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Takashi Hikage
Faculty of Information Science and Technology　Media and Network Technologies　Information Communication Systems
Associate Professor
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Last Updated :2024/05/09

Researcher Profile and Settings

Affiliation

  • Faculty of Information Science and Technology　Media and Network Technologies　Information Communication Systems

Job Title

  • Associate Professor

Degree

  • Ph.D（Hokkaido University）

URL

Research funding number

  • 30312391

ORCID ID

Researcher ID

  • E-3012-2012

J-Global ID

Research Interests

  • Pacemaker EMI   FDTD法   キャビティ   素子間相互結合   フェーズドアレーアンテナ   マイクロ波送電   無線LAN   アンテナ   太陽発電衛星   電磁界解析   ミリ波   スロットアンテナ   ミリ波技術   アンテナ技術   大規模電磁界解   並列計算   電磁環境適合性   マイクロ波   小型アンテナ   高効率   大規模電磁界解析   大型計算機   電磁環境   RFIDリーダ   多重反射環境   ミアンダラインアンテナ   FDTD解析   RF-ID   屋内電波伝搬   電磁干渉   環境電磁工学   情報通信工学   Information and Communication Eng.   

Research Areas

  • Manufacturing technology (mechanical, electrical/electronic, chemical engineering) / Electronic devices and equipment
  • Manufacturing technology (mechanical, electrical/electronic, chemical engineering) / Electrical power engineering
  • Manufacturing technology (mechanical, electrical/electronic, chemical engineering) / Communication and network engineering

Educational Organization

Academic & Professional Experience

  • 2022/06 - Today Faculty of Information Science and Technology, Hokkaido University Associate Professor
  • 2019/04 - Today Nagoya Institute of Technology Project Associate Professor
  • 2007 - 2022/05 Faculty of Information Science and Technology, Hokkaido University
  • 2019/04 - 2021/03 北海道大学 国際連携研究教育局

Education

  •        - 1999  Hokkaido University  Graduate School of Engineering
  •        - 1997  Hokkaido University  School of Engineering  Department of Electronics Engineering

Association Memberships

  • JAPANESE SOCIETY FOR MEDICAL AND BIOLOGICAL ENGINEERING   Bioelectromagnetics Society   THE INSTITUTE OF ELECTRICAL ENGINEERS OF JAPAN   米国電気電子学会(IEEE : the Institute of Electrical and Electronics Engineers, Inc.)   電子情報通信学会   

Research Activities

Published Papers

  • 表英毅, 佐藤彰弘, 木村翔, 田中翔馬, LIN Ho Yu, 日景隆, 山里敬也
    電子情報通信学会論文誌 B(Web) J106-B (11) 1881-0209 2023/11 [Refereed]
  • Kun Li, Takashi Hikage, Hiroshi Masuda, Etsuko Ijima, Akiko Nagai, Kenji Taguchi
    Scientific reports 13 (1) 17397 - 17397 2023/10/13 [Refereed]
     
    This study presents a parametric analysis of the steady-state temperature elevation in rat skin models due to millimeter wave exposure at frequencies from 6-100 GHz. The statistical data of the thickness of skin layers, namely epidermis, dermis, dermal white adipose tissue, and panniculus carnosus, were measured for the first time using the excised tissues of real male Sprague-Dawley rats. Based on the precise structure obtained from the histological analysis of rat skin, we solve the bioheat transfer equation to investigate the effects of changes in parameters, such as body parts and thermal constants, on the absorbed power density and temperature elevation of biological tissues. Owing to the notably thin dermal white adipose tissue layer, the surface temperature elevation in the rat head and dorsal skin at 6-100 GHz is 52.6-32.3% and 83.3-58.8% of the average values of different human skin models, respectively. Our results also reveal that the surface temperature elevation of rat skin may correlate with the tissue thickness and deep blood perfusion rates.
  • ETSUKO IJIMA, KUN LI, TAKASHI HIKAGE, AKIKO NAGAI, YASUTAKA MURAKAMI, TAKUJI ARIMA, TATSUYA ISHITAKE, HIROSHI MASUDA
    In Vivo 37 (5) 2092 - 2099 0258-851X 2023/08/31 [Refereed]
     
    BACKGROUND/AIM: The widespread use of fifth-generation 5G millimeter-waves (MMW) generates concern about potential adverse health effects. The latest international guidelines for MMW exposure adopt an absorbed power density (APD) of 200 W/m2 to avoid a local temperature rise of 5°C in human tissues as an operational adverse health effect threshold. However, because APD is estimated by simulations using human tissue models, it is unknown whether a similar value can be confirmed for living tissues. The aim of this study was to investigate the relationship between APD and skin temperature rise in vivo, and to validate the estimated values. MATERIALS AND METHODS: The rat dorsal skin was locally exposed to a 26.5 GHz quasi-MMW (qMMW) for 18 min using a patch antenna. The qMMW exposure intensities estimated by dosimetry were set to 0-500 W/m2 of APD. The temperatures in the dorsal skin and rectum were simultaneously measured during exposure. RESULTS: The qMMW-induced local temperature increase at different sites. The dorsal skin temperature increased by approximately 11.3°C at a maximum intensity of 500 W/m2, but the rectal temperature increased by only 0.6°C, indicating highly localized effects of exposure to rats. A significant correlation was observed between APD and skin temperature rise. The relationship provided a linear regression model, and a temperature rise of less than 5°C was estimated in the skin exposed to 200 W/m2 of APD. CONCLUSION: These results suggest that the operational threshold for the MMW exposure guidelines is valid under the present experimental conditions using rats.
  • 杉村海渡, 山本康平, 日景隆, 山崎圭子, 田村菜穂美, 宮下ちひろ, 岸玲子
    電子情報通信学会論文誌 B(Web) 電子情報通信学会 J106-B (8) 640 - 642 1881-0209 2023/08 [Refereed][Not invited]
     
    In order to achieve precise dosimetry analysis for epidemiologic research on RF exposure and adolescent health, we evaluate human body blockage characteristics on RF measurement due to deploying a personal exposure meter device near the subject's body, based upon FDTD analysis and actual measurements using an adolescent human phantom.
  • 西川拓次, 日景隆, 長岡智明
    電子情報通信学会論文誌 C(Web) J106-C (5) 1881-0217 2023/05 [Refereed]
  • Chihiro Miyashita, Keiko Yamazaki, Naomi Tamura, Atsuko Ikeda-Araki, Satoshi Suyama, Takashi Hikage, Manabu Omiya, Masahiro Mizuta, Reiko Kishi
    Environmental health and preventive medicine 28 22 - 22 2023/04 [Refereed]
     
    BACKGROUND: Concerns have been raised about the adverse health impacts of mobile device usage. The objective of this cross-sectional study was to examine the association between a child's age at the first use of a mobile device and the duration of use as well as associated behavioral problems among school-aged children. METHODS: This study focused on children aged 7-17 years participating in the Hokkaido Study on Environment and Children's Health. Between October 2020 and October 2021, the participants (n = 3,021) completed a mobile device use-related questionnaire and the strengths and difficulties questionnaire (SDQ). According to the SDQ score (normal or borderline/high), the outcome variable was behavioral problems. The independent variable was child's age at first use of a mobile device and the duration of use. Covariates included the child's age at the time of survey, sex, sleep problems, internet addiction, health-related quality of life, and history of developmental concerns assessed at health checkups. Logistic regression analysis was performed for all children; the analysis was stratified based on the elementary, junior high, and senior high school levels. RESULTS: According to the SDQ, children who were younger at their first use of a mobile device and used a mobile device for a longer duration represented more problematic behaviors. This association was more pronounced among elementary school children. Moreover, subscale SDQ analysis showed that hyperactivity, and peer and emotional problems among elementary school children, emotional problems among junior high school children, and conduct problems among senior high school children were related to early and long usage of mobile devices. CONCLUSIONS: Elementary school children are more sensitive to mobile device usage than older children, and early use of mobile devices may exacerbate emotional instability and oppositional behaviors in teenagers. Longitudinal follow-up studies are needed to clarify whether these problems disappear with age.
  • Shuhei Waki, Takuji Nishikawa, Takashi Hikage, Manabu Yamamoto
    URSI Radio Science Letters International Union of Radio Science (URSI) 4 1 - 3 2023/04 [Refereed]
     
    Experimental and numerical interference voltage estimations for the active implantable medical device electromagnetic interference due to the state-of-the-art cellular frequency bands are presented. A numerical model of a human torso phantom with a pacemaker was constructed for the finite element method simulation, and the interference voltage characteristics induced at the pacemaker connector at fourth-generation and fifth-generation sub-6 GHz bands were obtained. We confirmed the validity of the numerical results by comparing simulation results and measured interference voltages
  • Sachiko Kodera, Norika Miura, Yinliang Diao, Miyako Inoue, Takashi Hikage, Kenji Taguchi, Hiroshi Masuda, Akimasa Hirata
    IEEE Journal of Electromagnetics, RF and Microwaves in Medicine and Biology 7 (1) 65 - 72 2469-7249 2023/03 [Refereed]
  • Etsuko Ijima, Sachiko Kodera, Akimasa Hirata, Takashi Hikage, Akiko Matsumoto, Tatsuya Ishitake, Hiroshi Masuda
    Frontiers in public health 11 1225896 - 1225896 2023 [Refereed]
     
    INTRODUCTION: Limited information is available on the biological effects of whole-body exposure to quasi-millimeter waves (qMMW). The aim of the present study was to determine the intensity of exposure to increase body temperature and investigate whether thermoregulation, including changes in skin blood flow, is induced in rats under whole-body exposure to qMMW. METHODS: The backs of conscious rats were extensively exposed to 28 GHz qMMW at absorbed power densities of 0, 122, and 237 W/m2 for 40 minutes. Temperature changes in three regions (dorsal and tail skin, and rectum) and blood flow in the dorsal and tail skin were measured simultaneously using fiber-optic probes. RESULTS: Intensity-dependent temperature increases were observed in the dorsal skin and the rectum. In addition, skin blood flow was altered in the tail but not in the dorsum, accompanied by an increase in rectal temperature and resulting in an increase in tail skin temperature. DISCUSSION: These findings suggest that whole-body exposure to qMMW drives thermoregulation to transport and dissipate heat generated on the exposed body surface. Despite the large differences in size and physiology between humans and rats, our findings may be helpful for discussing the operational health-effect thresholds in the standardization of international exposure guidelines.
  • Keiko Yamazaki, Atsuko Ikeda-Araki, Chihiro Miyashita, Naomi Tamura, Toshio Yoshikawa, Takashi Hikage, Manabu Omiya, Masahiro Mizuta, Miwa Ikuyo, Kazuhiro Tobita, Teruo Onishi, Masao Taki, Soichi Watanabe, Reiko Kishi
    ENVIRONMENTAL RESEARCH 216 (Pt 1) 114429 - 114429 0013-9351 2023/01 [Refereed]
     
    The opportunities for exposure to radiofrequency electromagnetic fields (RF-EMF) among children are increasing. Children's exposure to RF-EMF in Japan was recorded using a personal exposure meter (ExpoM-RF), and factors associated with the exposure examined. A total of 101 children, aged 10-15 years old, participated in the prospective birth cohort "Hokkaido study". RF-EMF data were recorded in the 700 MHz-5.8 GHz frequency range for 3 days. The recorded data were summarized into six groups of frequency bands: downlink from mobile phone base stations (DL), uplink from mobile phones to a base station (UL), Wireless Local Area Network (LAN), terrestrial digital TV broadcasting (digital TV), 2.5 GHz and 3.5 GHz Time Division Duplex (TDD), 1.9 GHz TDD, and total (the summation of power density in all measured frequency bands). A questionnaire was used to document the internet environment (at home) and mobile phone usage. Personal RF-EMF exposure in Japanese children was lower than that reported in studies in Europe. The DL signals from mobile phone base stations were the most significant contributors to total exposure, while Wireless LAN and digital TV were only higher at home. The urban residence was consistently associated with increases in the four groups of frequency bands (DL, UL, digital TV, and TDD). TDD level has several associations with mobile phone usage (calls using mobile phones, video viewing, text message service, and online game). The association between inattention/hyperactivity subscale of the Strengths and Difficulties Questionnaire (SDQ) and higher Wireless LAN exposure at nighttime was also noted. Further studies with additional data will shed light on factors involved in RF-EMF exposure among Japanese children.
  • OMOTE Hideki, SATO Akihiro, KIMURA Sho, TANAKA Shoma, LIN HoYu, HIKAGE Takashi
    IEICE Transactions on Communications E105.B (10) 1219 - 1230 0916-8516 2022/10/01 [Refereed]
     
    In recent years, High-Altitude Platform Station (HAPS) has become the most interesting topic for next generation mobile communication systems, because platforms such as Unmanned Aerial Vehicles (UAVs), balloons, airships can provide ultra-wide coverage, up to 200km in diameter, from altitudes of around 20 km. It also offers resiliency to damage caused by disasters and so ensures the stability and reliability of mobile communications. In order to further integrate HAPS with existing terrestrial mobile communication networks in providing mobile services to users, radio wave propagation models such as terrain, vegetation loss, human shielding loss, building entry loss, urban/suburban areas must be taken into consideration when designing HAPS-based cell configurations. This paper proposes a human body shielding propagation loss model that considers the basic signal attenuation by the human body at high elevation angles. It also analyzes the effect of changes in actual urban/suburban environments due to the arrival of multipath radio waves for HAPS communications in the frequency range of 0.7 to 3.3GHz. Measurements in actual urban/rural environments in Japan and actual stratospheric base station measurements in Kenya are carried out to confirm the validity of the proposed model. Since the measured results agree well with the results predicted by the proposed model, the model is good enough to provide estimates of human loss in various environments.
  • Ozaki Ryunosuke, Hikage Takashi, Taguchi Kenji, Kashiwa Tatsuya, Inoue Miyako, Masuda Hiroshi, Ishitake Tatsuya
    IEEJ Transactions on Fundamentals and Materials 一般社団法人 電気学会 142 (6) 250 - 256 0385-4205 2022/06/01 [Refereed][Not invited]
     
    A novel 60 GHz band exposure set-up has been newly developed for studies on thermal thresholds of biological effects of humans exposed to millimeter waves (MMW) that are 5th generation wireless systems (5G) and beyond-5G candidate frequency bands. To achieve high duty exposure to 60 GHz at the desired area, the authors proposed a spatial synthetic beam-type exposure set-up consists of dielectric lens antennas that can irradiate focused beam. We applied orthogonalizing polarized feeding structure to eliminate interference fringes generated in the exposure area due to the combined two-directional beam radiations. Using FDTD simulation, electromagnetic fields distributions on the exposure area due to incident angles of the combined beams was estimated. In order to obtain exposure characteristics, we achieved exposure experiments of temperature rise measurements using a physical arm-shaped skin phantom and human forearm. The developed set-up enabled efficient and desired exposure control for the experiments to explore the biological effects of local exposure to MMWs on human volunteers.
  • OHTSUKA Atsuki, HIKAGE Takashi, ISHIOKA Ryota, HIGASHIYAMA Junji, IYAMA Takahiro, SUZUKI Yasunori
    IEICE transactions on electronics IEICE - Institute of the Electronics, Information and Communication Engineers J105-C (5) 157 - 166 1745-1353 2022/05/01 [Refereed]
     
    This paper describes a numerical assessment of implantable medical devices (implantable cardiac pacemaker/implantable defibrillator) electromagnetic interference (EMI) triggered by wireless devices. By using three-dimensional full-wave numerical simulation based on finite element method, interference voltage induced at the connector of pacemaker inside torso phantom that is used for in-vitro EMI assessment is obtained. We discuss EMI characteristics due to irradiation by slot antenna comparing with irradiation by a dipole antenna. Furthermore, in order to validate the simulated results, we achieved measurement of interference voltage induced at pacemaker connector inside test phantom using novel electro-optic sensor installed in a pacemaker mock-up.
  • SATO Ai, HIKAGE Takashi, OMIYA Manabu, FUTATSUMORI Syunichi, KOHMURA Akiko, YONEMOTO Naruto
    電子情報通信学会論文誌 C J105-C (5) 149 - 156 2432-6380 2022/05/01 [Refereed]
     
    We investigate the applicability of large-scale FDTD analysis to estimate precise radio wave propagation characteristics to design a newly developed wireless link system inside and outside aircraft. This paper predicts interference pass loss characteristics from the cabin to an external altimeter's vicinity using a small aircraft model in the 5G sub-6 GHz frequency bands. Applicability of path loss models, namely alpha beta gamma (ABG) or floating intercept (FI) models with their parameters derived from simulation data, are discussed.
  • HOR Mangseang, HIKAGE Takashi, YAMAMOTO Manabu
    IEICE Transactions on Communications E105.B (3) 285 - 294 0916-8516 2022/03/01 [Refereed]
     
    In this paper, a linear array of 4 leaf-shaped bowtie slot antennas is proposed for use in quasi-millimeter wave band. The slot antennas array is designed to operate at 28 GHz frequency band. The leaf-shaped bowtie slot antenna is a type of self-complementary antenna with low profile and low cost of fabrication. The proposed antenna structure offers improvement in radiation pattern, gain, and -10 dB impedance bandwidth. Through out of this paper radiation pattern, actual gain, and -10 dB impedance bandwidth are evaluated by Finite Different Time Domain (FDTD) simulation. Antenna characteristics are analyzed in the frequency range of 27 GHz to 29 GHz. To improve antenna characteristics such as actual gain and -10 dB impedance bandwidth, a dielectric superstrate layer with relative permittivity of 10.2 is placed on top of ground plane of the slot antennas array. Three antenna structures are introduced and compared. With two layers of dielectric superstrate on top of the antennas ground plane, analysis results show that -10 dB impedance bandwidth occupies the frequency range of 27.17 GHz to 28.39 GHz. Therefore, the operational impedance bandwidth is 1.22 GHz. Maximum actual gain of the slot antennas array with two dielectric superstrate layers is 20.49dBi and —3 dB gain bandwidth occupies the frequency range of 27.02 GHz to 28.57 GHz. To validate the analysis results, prototype of the designed slot antennas array is fabricated. Characteristics of the slot antennas array are measured and compared with the analysis results.
  • YAMAMOTO Naoya, HIKAGE Takashi, YAMAMOTO Manabu
    電子情報通信学会論文誌 B(Web) 電子情報通信学会 J105-B (3) 310 - 312 1881-0209 2022/03/01 [Refereed]
     
    This letter shows that it is possible to realize the wideband, cross-polarization suppressed planar antenna by constructing the 2×2 element array antenna using Both-sided MIC and Leaf-shaped bowtie slot radiating element.
  • HOR Mangseang, YAMAMOTO Naoya, HIKAGE Takashi, YAMAMOTO Manabu, UCHIDA Daisei, SHIRATO Yushi, KITA Naoki
    電子情報通信学会論文誌 B(Web) 電子情報通信学会 J105-B (3) 166 - 177 1881-0209 2022/03/01 [Refereed]
     
    In this paper, we focus on the leaf-shaped bow tie slot antenna as a wideband antenna that is indispensable for the realization of a high-frequency band distributed antenna system. For the case when a reflector is added to make the bidirectional antenna unidirectional, the design takes into consideration the influence of the reflector. For the case when even if the reflector is added, it is shown that the wide band of various antenna characteristics is possible. It is shown that a wide band of impedance characteristics is possible by adopting a quater-wave transformer as a matching circuit for impedance matching and obtaining double resonance characteristics. Measurement of prototype of designed antenna is perfomed in order to validate the effectiveness of the proposed antenna.
  • 大塚敦生, 日景隆, 石岡諒汰, 東山潤司, 井山隆弘, 鈴木恭宜
    電子情報通信学会論文誌 C(Web) J105-C (5) 1881-0217 2022 [Refereed]
  • Takashi Hikage, Ryunosuke Ozaki, Tatsuya Ishitake, Hiroshi Masuda
    Frontiers in public health 9 777712 - 777712 2021/12 [Refereed]
     
    The global spread of 5th generation (5G) wireless systems causes some concern about health effects of millimeter waves (MMW). To investigate biological effects of local exposure to 5G-MMW on human body, a novel 60 GHz band exposure setup was developed, and its performance was validated. A spatial synthetic beam-type exposure setup using two dielectric lens antennas was proposed to achieve high intensity 60 GHz irradiation to the target area of human skin. Variety distributions and intensities of electromagnetic fields at the exposed area, which is modified by incident angles of the combined beams, were simulated using finite-difference time-domain methods. The exposure performance we estimated was verified by temperature elevations of surface in a physical arm-shaped silicone phantom during the MMW exposure. The interference fringes generated in the exposed area due to the combined two-directional beam radiations were observed both in the simulation and in the phantom experiment but eliminated by applying an orthogonalizing polarized feeding structure. Under these exposure conditions, the local temperature changes, which could evoke warmth sensations, were obtained at the target area of the human forearm skin, which means the achievement of exposure performance we intended.
  • 尾崎龍之介, 日景隆
    電子情報通信学会論文誌 B(Web) 電子情報通信学会 J104-B (7) 648 - 649 1881-0209 2021/07 [Refereed]
     
    We have newly developed a novel 60 GHz band exposure setup for studies on thermal perception thresholds of biological effects for 5G and Beyond. To achieve high duty exposure on desired area at 60 GHz required, the authors proposed spatial synthetic type exposure setup consists of lens antennas that can irradiate focused beam. In order to obtain basic exposure performance, we used physical phantom and achieved exposure experiments of temperature rise measurements.
  • 山崎, 圭子, 荒木, 敦子, 田村, 菜穂美, 寺岡, 友里, 日景, 隆, 水田, 正弘, 大宮, 学, 岸, 玲子
    北海道公衆衛生学雑誌 北海道公衆衛生学会 34 (2) 14 - 21 0914-2630 2021/03 [Refereed]
     
    近年，電波ばく露環境は急速に変化していると考えられ，子どもの健康，特に精神神経発達への影響が懸念される．本研究の目的は，胎児期と出生後のばく露による子どもの精神神経発達への影響について先行研究を概観し，今後の研究の方向性を明らかにすることである．胎児期ばく露を扱った７編のうち３編で妊娠中の母の携帯電話使用状況と精神神経発達の間に負の関連が，１編で正の関連が報告されていた．出生後のばく露を扱った22編では，２編を除き，携帯電話使用状況または電波ばく露レベルと精神神経発達との負の関連が報告されていた．今後の研究では，携帯電話や電子機器の使用状況と電波ばく露による影響を独立に検討する必要がある．また，因果関係を考察するために適した前向き研究デザインを用いることが望ましい．さらに電波ばく露の背後にある交絡要因についても慎重に検討する必要がある． 近年，電波ばく露環境は急速に変化していると考えられ，子どもの健康，特に精神神経発達への影響が懸念される．本研究の目的は，胎児期と出生後のばく露による子どもの精神神経発達への影響について先行研究を概観し，今後の研究の方向性を明らかにすることである．胎児期ばく露を扱った７編のうち３編で妊娠中の母の携帯電話使用状況と精神神経発達の間に負の関連が，１編で正の関連が報告されていた．出生後のばく露を扱った22編では，２編を除き，携帯電話使用状況または電波ばく露レベルと精神神経発達との負の関連が報告されていた．今後の研究では，携帯電話や電子機器の使用状況と電波ばく露による影響を独立に検討する必要がある．また，因果関係を考察するために適した前向き研究デザインを用いることが望ましい．さらに電波ばく露の背後にある交絡要因についても慎重に検討する必要がある．
  • 伊藤涼音, 大塚敦生, 日景隆, 長岡智明, 和氣加奈子, 渡辺聡一
    電子情報通信学会論文誌 B(Web) 電子情報通信学会 J104-B (6) 500 - 502 1881-0209 2021 [Refereed]
     
    Local Specific Absorption Rate (SAR) enhancement mechanism due to implanted metal plates in humans exposed to RF electromagnetic fields are investigated. In some cases, a combination of two metal plates is applied instead of a single plate because of surgical reasons such as space limit, stability, strength, and so on. The main objective of this study is to evaluate RF exposure conditions under which the SAR is enhanced when two metal plates are placed in parallel.
  • Toru Ishihara, Keiko Yamazaki, Atsuko Araki, Yuri Teraoka, Naomi Tamura, Takashi Hikage, Manabu Omiya, Masahiro Mizuta, Reiko Kishi
    International Journal of Environmental Research and Public Health 17 (9179) 1 - 20 1661-7827 2020/12 [Refereed]
     
    With increasing use of mobile phones, exposure to radiofrequency electromagnetic field (RF-EMF) in the high-frequency band associated with mobile phones has become a public concern, with potentially adverse effects on cognitive function in children and adolescents. However, findings regarding the relation of RF-EMF and cognitive function in children and adolescents have been inconsistent due to a number of study design-related factors, such as types of exposure and outcome measures, age of participants, and the era of study conduction. The present literature review focused on these possible factors that could explain this inconsistency. This review identified 12 eligible studies (participants ages 4 to 17 years) and extracted a total 477 relations. In total, 86% of the extracted relations were not statistically significant; in the remaining 14%, a negative relation between RF-EMF and cognitive performance was detected under limited conditions: when (1) RF-EMF was assessed using objective measurement not subjective measurement (i.e., questionnaire), (2) participants were relatively older (12 years and above) and had greater opportunity of exposure to RF-EMF, and (3) the collection of cognitive function data was conducted after 2012. Given that 86% of the extracted relations in this analysis were not statistically significant, the interpretation should be approached with caution due to the possibility of the 14% of significant relationships, extracted in this review, representing chance findings.
  • Takashi Hikage
    URSI Radio Science Letters 2 1 - 3 2020/11 [Refereed]
  • Masakazu YAMAGISHI, Takashi HIKAGE, Nobuaki KUNO, Mitsuki NAKAMURA, Wataru YAMADA, Yasushi TAKATORI
    電子情報通信学会論文誌 C Vol.J102-C (No.5) 131 - 138 1881-0217 2019/05/10 [Refereed][Not invited]
  • Tetsuya Sekiguchi, Takashi Hikage, Manabu Yamamoto, Toshio Nojima, Shunichi Futatsumori, Kazuyuki Morioka, Akiko Kohmura, Naruto Yonemoto
    IEICE Communications Express Vol. 8 (Iss. 5) 129 - 134 2187-0136 2019/05 [Refereed][Not invited]
     
    The aim of this study is to develop an accurate and reliable method for estimating the propagation characteristics inside and outside aircraft cabins so as to advance the radio link design techniques for WAIC systems. This paper uses the FDTD method and large-scale parallel computing to conduct the world's first study on the propagation characteristics of signals emitted by a transmit antenna above the wing tip to WAIC antennas installed inside and outside the aircraft cabin (Airbus 320-200). EMF distributions created by a 4.4 GHz wireless transmitter inside the cabin are analyzed and propagation characteristics are determined from the analysis results.
  • Shunichi Futatsumori, Kazuyuki Morioka, Akiko Kohmura, Naruto Yonemoto, Takashi Hikage, Tetsuya Sekiguchi, Manabu Yamamoto, Toshio Nojima
    Applied Computational Electromagnetics Society Journal 34 (2) 365 - 368 1054-4887 2019/02 [Refereed][Not invited]
     
    Radio altimeters and wireless avionics intra-communication (WAIC) systems are both operated at the frequency band 4,200 MHz-4,400 MHz. Hence, a detailed analysis is required for spectrum sharing in the same band. Firstly, a large-scale finite-difference time-domain analysis is performed to obtain the detailed characteristics of the electromagnetic field (EMF) around the three-dimensional Airbus A320 aircraft model, which assumes that a WAIC device is located inside the cabin. Then, the 4-GHz EMF propagation characteristics are evaluated based on the analyzed results. Finally, the methodology of the interference analysis is discussed based on the obtained EMF characteristics.
  • Takashi Hikage
    電子情報通信学会論文誌 B Vol.J102-B (No. 2) 72 - 79 2019/02/01 [Refereed][Not invited]
  • Takashi Hikage, Toshio Nojima, Eiji Yonezawa, Atsushi Sakai, Kouji Osawa
    Transactions of Japanese Society for Medical and Biological Engineering 55 (1) 32 - 38 1347-443X 2017 [Refereed][Not invited]
     
    This paper describes local specific absorption rate (SAR) and temperature elevation estimation in a human head model implanted with wireless power transfer technology (WPT) -based vision prosthesis system, as an example of the medical application of WPT and the safety issue of WPT-related electromagnetic field (EMF). A high-resolution numerical model of a human head and an internally implanted vision prosthesis component including WPT coil was constructed. Using finite-difference time-domain analysis, the electromagnetic field distribution inside the human head was calculated and exposure levels to ensure human safety were obtained. Implantable medical devices such as implantable pacemakers and capsule endoscopes are an important application of WPT. Traditionally, these devices use rechargeable or disposable batteries that constitute a source of constraints including large device size and limited operation life. WPT is now considered a key solution to these problems. WPT-based implantable devices are expected to offer patients better mobility and improved quality of life. Using inductive coupling to link the external power source to the implanted device is a sensible choice when considering short-range wireless power transfer for biomedical implants. However, EMF emitted by wireless devices is a subject in the radio radiation protection guidelines on human exposure to EMF. In Japan, Radio Radiation Protection Guidelines for Human Exposure to Electromagnetic Fields has been published. However, these guidelines provide no quantitative discussions about their relevance in patients with WPT-based active implantable devices. It is very important to estimate the amount and nature of EMF that users are likely to be exposed. Given the progress in biomedical technologies, the number of such users will rapidly increase in the near future. Based on precise numerical simulation, we showed that the estimated SAR and temperature elevation in the human head model implanted with a WPT-based vision prosthesis system were within the safety limits described in the guidelines.
  • Naoki Tanaka, Takashi Hikage, Toshio Nojima
    IEICE TRANSACTIONS ON ELECTRONICS E99C (7) 809 - 812 1745-1353 2016/07 [Refereed][Not invited]
     
    This paper describes a numerical assessment methodology of pacemaker EMI triggered by HF-band wireless power transfer system. By using three dimensional full-wave numerical simulation based on finite element method, interference voltage induced at the connector of the pacemaker inside the phantom that is used for in-vitro EMI assessment is obtained. Simulated example includes different exposure scenarios in order to estimate the maximum interference voltage.
  • Takashi Hikage, Toshio Nojima, Hiroshi Fujimoto
    PHYSICS IN MEDICINE AND BIOLOGY 61 (12) 4522 - 4536 0031-9155 2016/06 [Refereed][Not invited]
     
    The electromagnetic interference (EMI) imposed on active implantable medical devices by wireless power transfer systems (WPTSs) is discussed based upon results of in vitro experiments. The purpose of this study is to present comprehensive EMI test results gathered from implantable-cardiac pacemakers and implantable cardioverter defibrillators exposed to the electromagnetic field generated by several WPTSs operating in low-frequency (70 kHz-460 kHz) and high-frequency (6.78 MHz) bands. The constructed in vitro experimental test system based upon an Irnich's flat torso phantom was applied. EMI test experiments are conducted on 14 types of WPTSs including Qi-compliant system and EV-charging WPT system mounted on current production EVs. In addition, a numerical simulation model for active implantable medical device (AIMD) EMI estimation based on the experimental test system is newly proposed. The experimental results demonstrate the risk of WPTSs emitting intermittent signal to affect the correct behavior of AIMDs when operating at very short distances. The proposed numerical simulation model is applicable to obtain basically the EMI characteristics of various types of WPTSs.
  • FDTD解析による高速鉄道車両内5GHz帯無線接続サービスの伝搬特性推定
    白船 雅巳, 日景 隆, 野島 俊雄, 佐々木 元晴, 山田 渉, 杉山 隆利
    電子情報通信学会論文誌 B Vol.J97-B (No.9) 762 - 769 2014/09 [Refereed][Not invited]
  • 白船雅巳, 日景 隆, 野島俊雄, 二ッ森俊一, 河村暁子, 米本成人
    電子情報通信学会論文誌 C J97-C (No. 5) 197 - 200 1881-0217 2014/05 [Refereed][Not invited]
  • Shunichi Futatsumori, Kazuyuki Morioka, Akiko Kohmura, Narutoc Yonemoto, Masami Shirafune, Takashi Hikage, Toshio Nojima
    Annual Review of Progress in Applied Computational Electromagnetics 2014-January 119 - 123 2014 [Refereed]
     
    Electromagnetic field (EMF) propagation characteristics including the whole body of a Boeing 777 class large passenger aircraft is analyzed by a parallel computing finite-difference time-domain technique. The analyzed EMF distributions in the aircraft cabin are in good agreement with measured distributions. The developed EMF analysis method can be applied for electromagnetic compatibility evaluations of aircrafts.
  • Takuma Suzuki, Takashi Hikage, Toshio Nojima
    2013 IEEE MTT-S International Microwave Workshop Series on RF and Wireless Technologies for Biomedical and Healthcare Applications 373 - 375 2377-0260 2013 [Refereed][Not invited]
     
    A numerical assessment methodology to understand the EMI imposed by magnetic resonance type wireless power transfer systems on active implantable medical devices (implantable cardiac pacemaker/cardioverter defibrillator) is introduced. A numerical estimation model that consists of magnetic resonant coils and a human torso phantom with a pacemaker model is constructed. Numerical simulation based on the finite element method yields the interference voltage induced at the connector of the pacemaker inside the torso phantom. Our example assumes magnetic resonance coils operating in the frequency band of 10 MHz. © 2013 IEEE.
  • KAWAMURA Yoshifumi, HIKAGE Takashi, NOJIMA Toshio, FUKUI Koh, FUJIMOTO Hiroshi, TOYOSHIMA Takeshi
    BME Japanese Society for Medical and Biological Engineering 50 (3) 289 - 298 1347-443X 2012/06 [Refereed][Not invited]
     
    Methods and results of in vitro experiments examining the electromagnetic interference (EMI) imposed on active implantable medical devices (AIMDs) by electronic article surveillance (EAS) systems are presented. Examined EAS systems include eleven models provided by four manufacturers. They are classified into four categories according to operating principle, and consist of one magnetic-type system, four acousto-magnetic type systems, five electromagnetic-type systems, and one microwave-type system. Examined AIMDs include five models of implantable cardiac pacemakers and five models of implantable cardioverter defibrillators (ICDs) provided by six manufacturers. These EAS systems and AIMDs are currently available in the Japanese market. The in vitro test system is based upon Irnich's flat torso phantom. The observed EMI on pacemakers is either missing pulses or undesirable generation of asynchronous pulses. The observed EMI on ICDs are inappropriate tachyarrhythmia detection and erroneous delivery of therapy. To summarize the results, in the worst case for pacemakers, interference occurred when approaching the EAS system up to 90 cm and entering the gate of the EAS system. The most significant effect was complete omission of pacing pulse and continuous generation of asynchronous pulses. These were observed when the pacemaker was set at maximum sensitivity. In the worst case for ICDs, interference occurred when approaching the EAS pedestal up to 90 cm within the gate. The most significant effect was inappropriate or inhibited tachyarrhythmia detection at 60 cm. These effects were drastically suppressed when the sensitivity was reduced and when the AIMD was far from the EAS system and magnetic field was attenuated. All AIMDs that experienced EMI returned to normal operation mode upon departing the EAS system.
  • Marie-Christine Gosselin, Guenter Vermeeren, Sven Kuehn, Valpre Kellerman, Stefan Benkler, Tero M. I. Uusitupa, Wout Joseph, Azeddine Gati, Joe Wiart, Frans J. C. Meyer, Luc Martens, Toshio Nojima, Takashi Hikage, Quirino Balzano, Andreas Christ, Niels Kuster
    IEEE TRANSACTIONS ON ELECTROMAGNETIC COMPATIBILITY 53 (4) 909 - 922 0018-9375 2011/11 [Refereed][Not invited]
     
    The demonstration of compliance with guidelines for human exposure to base-station antennas can be a time consuming process or often results in overly conservative estimates. To alleviate this burden and reduce the overestimation, approximation formulas for the whole-body average specific absorption rate (SAR) and the peak spatial SAR of human bodies using readily available basic antenna parameters have been developed and validated in this study. The formulas can be used for adults standing in the radiating near field of base-station antennas operating between 300 MHz and 5 GHz, at distances larger than 200 mm. It is shown that the 95th-percentile absorption for the human population can be well approximated by the absorption mechanism and statistical data of weight, height, and body-mass index of the human population. The validation was performed numerically using three anatomical humanmodels (Duke, Ella, and Thelonious) exposed to 12 generic base-station antennas in the frequency range 300 MHz to 5 GHz at six distances between 10 mm and 3 m. From the 432 evaluated configurations, the estimation formulas for adult models are proven to be conservative in predicting the SAR exposure values of the two adults, but as expected not of the child.
  • A. Y. Simba, S. Watanabe, T. Hikage, T. Nojima
    IET SCIENCE MEASUREMENT & TECHNOLOGY 5 (6) 225 - 230 1751-8822 2011/11 [Refereed][Not invited]
     
    A spherical phantom head irradiated with a mobile phone was placed in close proximity to a metallic wall and its specific absorption rates (SARs) were investigated both experimentally and numerically. The main goal of this study was to determine the effect of the reflected electromagnetic fields from the walls on the maximum spatial average 10 g SAR. The mobile phone was modelled as a half-wavelength dipole antenna operating in the 900 MHz range, radiating a constant output power. Two wall arrangements were considered and the change in the SARs with the distance from the wall was recorded. Measured SAR results presented in this work are the first of their kind in the study of the effect of the radio frequency exposure from mobile phones used near metallic walls. Simulated results were obtained using the finite-difference time-domain method. A good agreement between the experiment and the simulation was obtained. When the phantom was placed at a distance of 64 mm from the wall, the SARs obtained were higher than their free-space values by 38, 54 and 82% for the phantom-dipole antenna separation distances of 16, 22 and 30 mm, respectively.
  • Norio Imai, Mayumi Kawabe, Takashi Hikage, Toshio Nojima, Satoru Takahashi, Tomoyuki Shirai
    SYSTEMS BIOLOGY IN REPRODUCTIVE MEDICINE 57 (4) 204 - 209 1939-6368 2011/08 [Refereed][Not invited]
     
    In recent years concern has arisen whether carrying a cellular phone near the reproductive organs such as the testes may cause dysfunction and particularly decrease in sperm development and production, and thus fertility in men. The present study was performed to investigate the effects of a 1.95 GHz electromagnetic field on testicular function in male Sprague-Dawley rats. Five week old animals were divided into 3 groups of 24 each and a 1.95-GHz wide-band code division multiple access (W-CDMA) signal, which is used for the freedom of mobile multimedia access (FOMA), was employed for whole body exposure for 5 hours per day, 7 days a week for 5 weeks (the period from the age of 5 to 10 weeks, corresponding to reproductive maturation in the rat). Whole-body average specific absorption rates (SAR) for individuals were designed to be 0.4 and 0.08 W/kg respectively. The control group received sham exposure. There were no differences in body weight gain or weights of the testis, epididymis, seminal vesicles, and prostate among the groups. The number of sperm in the testis and epididymis were not decreased in the electromagnetic field (EMF) exposed groups, and, in fact, the testicular sperm count was significantly increased with the 0.4 SAR. Abnormalities of sperm motility or morphology and the histological appearance of seminiferous tubules, including the stage of the spermatogenic cycle, were not observed. Thus, under the present exposure conditions, no testicular toxicity was evident.
  • Takashi Hikage, Yoshifumi Kawamura, Toshio Nojima, Ben Koike, Hiroshi Fujimoto, Takeshi Toyoshima
    2011 IEEE MTT-S International Microwave Workshop Series on Innovative Wireless Power Transmission: Technologies, Systems, and Applications 109 - 112 2011 [Refereed][Not invited]
     
    This paper describes the electromagnetic interference (EMI) characteristics of active implantable medical devices based on assessments of Radio Frequency Identification interrogators. Typical examples of interrogators operating in various RF bands are tested to estimate the EMI experienced by implantable-cardiac pacemakers and -cardioverter-defibrillators. The EMI occurrence mechanism and some experimental EMI evaluation results for typical devices are shown. Observed characteristics of the EMI are discussed based upon the transmission radio wave specifications. This discussion can give a good perspective on the same EMI issue raised by wireless power transmission systems. © 2011 IEEE.
  • Yoshifumi Kawamura, Takashi Hikage, Toshio Nojima
    IEICE TRANSACTIONS ON COMMUNICATIONS E93B (10) 2636 - 2643 0916-8516 2010/10 [Refereed][Not invited]
     
    The purpose of this study is to establish a whole-body averaged specific absorption rate (WB-SAR) estimation method using the power absorbed by humans; a cylindrical-external field scanning technique is used to measure the radiated RF (radio-frequency) power. This technique is adopted with the goal of simplifying the estimation of the exposure dosimetry of humans who have different postures and/or sizes. In this paper, to validate the proposed measurement method, we subject numerical human phantom models and cylindrical scanning conditions to FDTD analysis. We design a radiation system that uses a dielectric lens to achieve plane-wave irradiation of tested human phantoms in order to develop an experimental WB-SAR measurement system for UHF far-field exposure condition. In addition, we use a constructed SAR measurement system to confirm absorbed power estimations of simple geometrical phantoms and so estimate measurement error of the measurement system. Finally, we discuss the measurement results of WB-SARs for male adult and child human phantom models.
  • Atsushi Kitagawa, Takashi Hikage, Toshio Nojima, Ally Y. Simba, Soichi Watanabe
    IEICE TRANSACTIONS ON COMMUNICATIONS E93B (7) 1839 - 1846 0916-8516 2010/07 [Refereed][Not invited]
     
    The purpose of this study is to estimate the possible effect of cellular radio on implantable cardiac pacemakers in elevators. We previously investigated pacemaker EMI in elevator by examining the E-field distribution of horizontal plane at the height of expected for implanted pacemakers inside elevators. In this paper, we introduce our method for estimating EMI impact to implantable cardiac pacemakers using EMF distributions inside the region of the human body in which pacemakers are implanted. Simulations of a human phantom in an elevator are performed and histograms are derived from the resulting EMF distributions. The computed results of field strengths are compared with a certain reference level determined from experimentally obtained maximum interference distance of implantable cardiac pacemakers. This enables us to carry out a quantitative evaluation of the EMI impact to pacemakers by cellular radio transmission. This paper uses a numerical phantom model developed based on an European adult male. The simulations evaluate EMI on implantable cardiac pacemakers in three frequency bands. As a result, calculated E-field strengths are sufficiently low to cause the pacemaker to malfunction in the region examined.
  • Yoshifumi Kawamura, Takashi Hikage, Toshio Nojima
    IEICE TRANSACTIONS ON COMMUNICATIONS E93B (7) 1826 - 1833 0916-8516 2010/07 [Refereed][Not invited]
     
    The aim of this study is to develop a new whole-body averaged specific absorption rate (SAR) estimation method based on the external-cylindrical field scanning technique. This technique is adopted with the goal of simplifying the dosimetry estimation of human phantoms that have different postures or sizes. An experimental scaled model system is constructed. In order to examine the validity of the proposed method for realistic human models, we discuss the pros and cons of measurements and numerical analyses based on the finite-difference time-domain (FDTD) method. We consider the anatomical European human phantoms and plane-wave in the 2 GHz mobile phone frequency band. The measured whole-body averaged SAR results obtained by the proposed method are compared with the results of the FDTD analyses.
  • Yoko Mizuno, Yoshiya Moriguchi, Takashi Hikage, Yasuo Terao, Takashi Ohnishi, Toshio Nojima, Yoshikazu Ugawa
    BIOELECTROMAGNETICS 30 (7) 536 - 544 0197-8462 2009/10 [Refereed][Not invited]
     
    Use of the third generation mobile phone system is increasing worldwide. This is the first study to investigate the effects of the third generation system on regional cerebral blood flow (rCBF) in humans. We compared effects of the electromagnetic field (EMF) emitted from the Wideband Code Division Multiple Access (W-CDMA) cellular system versus sham control exposure on rCBF in humans. Nine healthy male Volunteers participated in this study. Positron emission tomography (PET) scans were obtained before, during, and after unilateral 30min EMF exposure. The subtraction analysis revealed no significant rCBF changes caused by the EMF conditions compared with the sham exposure, suggesting that EMF emitted by a third generation mobile phone does not affect rCBF in humans. Bioelectromagnetics 30:536-544, 2009. (C) 2009 Wiley-Liss, Inc.
  • Louis-Ray Harris, Takashi Hikage, Toshio Nojima
    IEICE TRANSACTIONS ON FUNDAMENTALS OF ELECTRONICS COMMUNICATIONS AND COMPUTER SCIENCES E92A (9) 2177 - 2183 0916-8508 2009/09 [Refereed][Not invited]
     
    The Finite-Difference Time-Domain (FDTD) technique is presented in this paper as an estimation method for radio propagation prediction in large and complex wireless local area network (WLAN) environments. Its validity is shown by comparing measurements and Ray-trace method with FDTD data. The 2 GHz (802.11 b/g) and 5 GHz (802.11 a) frequency bands are used in both the calculations and experiments. The electric field (E-field) strength distribution has been illustrated in the form of histograms and cumulative ratio graphs. By using the FDTD method to vary the number of human bodies in the environment, the effects on E-field distribution due to human body absorption are also observed for 5 GHz WLAN design.
  • Louis-Ray Harris, Takashi Hikage, Toshio Nojima
    IEICE TRANSACTIONS ON ELECTRONICS E92C (9) 1182 - 1187 0916-8524 2009/09 [Refereed][Not invited]
     
    The purpose of this paper is to investigate the possible impact of cellular phones' signals on implantable cardiac pacemakers in elevators. This is achieved by carrying out precise numerical simulations based on the Finite-Difference-Time-Domain method to examine the electromagnetic fields in elevator models. In order to examine the realistic and complicated situations where humans are present in the elevator, we apply the realistic homogeneous human phantom and cellular radios operating in the frequency bands 800 MHz, 1.5 GHz and 2 GHz. These computed results of field strength inside the elevator are compared with a certain reference level determined from the experimentally obtained maximum interference distance of implantable cardiac pacemakers. This enables us to carry out a quantitative evaluation of the EMI risk to pacemakers by cellular radio transmission. The results show that for the case when up to 5 mobile radio users are present in the elevator model used. there is no likelihood of pacemaker malfunction for the frequency bands 800 MHz, 1.5 GHz and 2 GHz.
  • Masuda, Hiroshi, Ushiyama, Akira, Takahashi, Miyuki, Wang, Jianqing, Fujiwara, Osamu, Hikage, Takashi, Nojima, Toshio, Fujita, Koji, Kudo, Motoshige, Ohkubo, Chiyoji
    RADIATION RESEARCH 172 (1) 66 - 73 0033-7587 2009/07 [Refereed][Not invited]
     
    The aim of this study was to determine whether albumin leakage and dark neurons were present in rat brains 14 and 50 days after a single 2-h exposure to a 915 MHz electromagnetic field, as reported by Salford et al. (Environ. Health Perspect. 111, 881-883, 203). Sixty-four male F344 rats (12 weeks old) were exposed to a 915 MHz electromagnetic field at whole-body average specific absorption rates of 0, 0.02, 0.2 and 2.0 W/kg in TEM cells for 2 h, following the protocol reported by Salford et al. The brains were examined histologically and immunohistochemically. No albumin immunoreactivity was observed in the exposed groups. In addition, dark neurons, assessed using hematoxylin and eosin staining, were rarely present, with no statistically significant difference between exposed and sham-exposed animals. This study thus failed to confirm the results of Salford et al. (C) 2009 by Radiation Research Society
  • Shunichi Futatsumori, Masato Furuno, Takashi Hikage, Toshio Nojima, Akihiko Akasegawa, Teru Nakanishi, Kazunori Yamanaka
    IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY 19 (3) 3595 - 3599 1051-8223 2009/06 [Refereed][Not invited]
     
    The intermodulation distortion (IMD) of a 5-GHz HTS resonator is precisely measured and a nonlinear analysis is conducted. When designing a radio communication system that uses an HTS microwave device, the device's IMD characteristic is one of the most important problems that must be quantitatively evaluated. The amplitudes of third-order IMD (IMD3) and higher-order IMD, which are generated in an HTS resonator given a two-tone fundamental signal, are measured in detail using a fundamental signal cancellation circuit. Moreover, the relative phase of IMD3 is obtained by using a novel measurement system constructed around a reference IMD3 generator. The measured IMD3 phase shows a drastic change in a relatively low IMD3 amplitude region. In addition, the measured resonator exhibits strong higher-order IMD. A nonlinear evaluation using complex power series representation confirms that the drastic phase change may be due to the higher-order distortions present in IMD3.
  • Ally Y. Simba, Takashi Hikage, Soichi Watanabe, Toshio Nojima
    IEEE TRANSACTIONS ON MICROWAVE THEORY AND TECHNIQUES 57 (5) 1250 - 1259 0018-9480 2009/05 [Refereed][Not invited]
     
    This paper presents a detailed numerical investigation to determine whether or not an increased specific absorption rate (SAR) in an adult using a mobile phone inside an elevator due to the multireflections of electromagnetic fields from the walls exceed the RF-exposure guidelines. A fully realistic heterogeneous human body model and an actual elevator size were employed. The nonuniform mesh finite-difference time-domain technique and a supercomputer were employed to obtain the SAR and other important parameters. The mobile phone was modeled as a lambda/2 dipole antenna placed at a distance of 16 mm from the head. For computations, operating frequencies of 900, 1500, and 2000 MHz with transmitting power of 250 mW were used. Computed results show that the peak spatial-average 10-g SAR depends on the position of the passenger and the antenna against the elevator walls. We observed a substantial increase in the whole-body average SAR and peak 10-g SAR values of the passenger in the elevator over their respective free-space values. However, the maximum values obtained do meet the basic restrictions described in the international RF safety guidelines. For example, the maximum values of the whole-body average and peak spatial-average SAR were 4.4% and 78% of the international RF safety guideline, respectively.
  • Shunichi Futatsumori, Takashi Hikage, Toshio Nojima, Akihiko Akasegawa, Teru Nakanishi, Kazunori Yamanaka
    IEICE TRANSACTIONS ON ELECTRONICS E92C (3) 307 - 314 0916-8524 2009/03 [Refereed][Not invited]
     
    We propose a new hand selective stop filter construction to decrease the out of band intermodulation distortion (IMD) noise generated in the transmitting power amplifier. Suppression of IMD noise directly improves the adjacent channel leakage power ratio (ACLR). A high-temperature superconducting (FITS) device with extremely high-Q performance with very small hybrid IC pattern Would make it possible to implement the proposed filter construction as a practical device. To confirm the effectiveness of the HTS reaction-type filter (HTS-RTF) in improving ACLR, investigations based on both experiments and numerical analyses,ire carried out. The structure of a 5-GHz split open-ring resonator is investigated its targets include high-unload Q-factor, low Current densities. and low radiation. A designed 5-GHz HTS-RTF with 4 MHz Suppression bandwidth and more than 40 dB MHz(-1) sharp skirt is fabricated and experimentally investigated. The measured ACLR Values are improved by a maximum of 12.8 dB and are constant Lip to the passband signal power of 40 dBm. In addition. to examine the power efficiency improvement offered by noise Suppression of the HTS-RTF numerical analyses based oil measured results of gallium nitride HEMT power amplifier characteristics are conducted. The analyzed results shows the drain efficiency of the amplifier can be improved to 44.2% of the amplifier with the filter front the 15.7% of the without filter.
  • Shunichi Futatsumori, Yoshifumi Kawamura, Takashi Hikage, Toshio Nojima, Ben Koike, Hiroshi Fujimoto, Takeshi Toyoshima
    Journal of Arrhythmia 25 (3) 142 - 152 1883-2148 2009 [Refereed][Not invited]
     
    Introduction: The electromagnetic interference (EMI) of active implantable medical devices (AIMDs) due to 125-135kHz and HF (13.56MHz) radio-frequency identification (RFID) reader/writers are discussed based on in vitro experiments. The purpose of this paper is to clarify the detailed EMI occurrence conditions of both implantable cardiac pacemakers and implantable cardioverter defibrillators (ICDs) when used in proximity to commercial low-band RFID reader/writers. Methods and results: A total of 20 types of pacemakers and 7 types of ICDs from 9 manufacturers are used in the experiments. The tested RFID reader/writers are 4 types of 125-135 kHz antennas and 26 types of HF antennas. The test system is newly constructed based on the one previously proposed for the estimation of EMI due to mobile phones. The measured reactions are missing of pacing pulses and generation of asynchronous pulses for pacemaker functions and inappropriate tachyarrhythmia detection and delivery of therapy for ICDs. In addition, measured EMI characteristics strongly depend on intermittent period of RFID signals. However, all AIMDs tested return to normal operation once removed from RFID exposure. Conclusion: The detailed EMI characteristics of AIMDs and low-band RFID reader/ writers are obtained to prevent adverse interactions. © 2009, Japanese Heart Rhythm Society. All rights reserved.
  • S. Futatsumori, T. Hikage, T. Nojima, A. Akasegawa, T. Nakanishi, K. Yamanaka
    SUPERCONDUCTOR SCIENCE & TECHNOLOGY 21 (4) 0953-2048 2008/04 [Refereed][Not invited]
     
    A new kind of high- temperature superconducting ( HTS) transmitting filter based on a reaction- type resonator is presented. The purpose of an HTS reaction- type filter ( HTS- RTF) is to eliminate the intermodulation distortion noise generated by microwave power amplifiers such as those employed in mobile base stations. An HTS- RTF enables both higher power handling capability and sharper cutoff characteristics compared to existing planar- type HTS transmitting filters, since a reaction- type resonator does not resonate with high power fundamental signals. To achieve steep skirt characteristics and high power handling capability simultaneously, a 5 GHz three- pole HTS- RTF using a split open- ring resonator is designed. This split open- ring resonator offers low maximum current densities and a high- unloaded Q factor with low radiation. The designed prototype filter has Chebyshev characteristics with a centre frequency of 4.95 GHz and a bandwidth of 1.5 MHz. The HTS- RTF is fabricated using a double- sided YBa(2)C(3)O(7-delta) thin film deposited on a 0.5 mm thick MgO substrate. The measured filter shows an insertion loss of less than 0.1 dB and a third intermodulation distortion value of - 56.7 dBc for a 40 dBm passband signal. In addition, adjacent channel leakage power ratio ( ACLR) measurements using an actual wideband CDMA signal confirm an ACLR improvement of about 10 dB for a four- carrier signal with power up to 40 dBm.
  • ABIKO Yusuke, HARRIS Louis-Ray, HIKAGE Takashi, NOJIMA Toshio, WATANABE Soichi, SHINOZUKA Takashi
    The transactions of the Institute of Electronics, Information and Communication Engineers. B 一般社団法人電子情報通信学会 J90-B (11) 1097 - 1105 1344-4697 2007/11 [Refereed][Not invited]
     
    乗り物やオフィスなどの閉空間内でマイクロ波が発射される場合,壁や床,人体などでの散乱吸収によって内部に多くの多重波が発生して,自由空間内とは性質の異なる複雑な電磁界分布が形成される.このような電磁界分布を精度良く推定することが,例えば閉空間内での携帯電話無線回線設計の面から,またEMCや電波防護の評価を行うために必要である.筆者らは通勤電車内での携帯電話電波による心臓ペースメーカリスク評価法を目的に大規模FDTD(Finite Difference Time Domain)解析法を採用し,また空間内に局所的に点在発生する強い電磁界領域(ホットスポット)を強度について集約的に評価するためにヒストグラムの適用を先に提案している.本論文は,通勤電車に加えて大型旅客機を対象空間に,また無線LANアクセスポイントと携帯電話をマイクロ波発射源として電界に更に磁界分布の解析を行い,心臓ペースメーカリスクに加えて新たに無線LANサービスエリアの評価を行う.人体の存在による影響を含めて,レイトレースなど従来の推定法では困難であった高精度で緻密な電磁界解析と評価ができることを示す.電車内での実験測定により本解析評価法の妥当性を確認する.
  • S. Futatsumori, T. Hikage, T. Nojima, A. Akasegawa, T. Nakanishi, K. Yamanaka
    ELECTRONICS LETTERS 43 (17) 956 - 957 0013-5194 2007/08 [Refereed][Not invited]
     
    Novel planar construction of high-temperature superconducting (HTS) filters that improve power-handling capability is proposed. Split openring resonators are developed to be used in reaction-type transmitting filters that have very sharp bandstop characteristics. Resonator structotes to achieve high-unloaded Q-factors and low radiation as well as low surface current densities in the passband are numerically investigated for 5 GHz band operation. Low surface current densities reduce the generation of inter-modulation distortions. Measurements confirm an unloaded Q-factor of 68 000 and third intermodulation distortion of -82 dBc at 30 dBm input power.
  • FUTATSUMORI Shunichi, HIKAGE Takashi, NOJIMA Toshio
    The transactions of the Institute of Electronics, Information and Communication Engineers. C 一般社団法人電子情報通信学会 J89-C (5) 266 - 273 1345-2827 2006/05 [Refereed][Not invited]
     
    高温超伝導体(High-Temperature Superconductor, HTS)の有望なマイクロ波デバイス応用の一つにフィルタがある.HTSフィルタを送信系に適用する場合,電流がデバイスの一部に集中するため耐電力(許容入力)に制限が生じる.本論文では,高Q値を維持しながら電流密度分散可能な構造をもつ新たな分割オープンリング共振器を適用した,マイクロ波送信用超伝導リアクション型フィルタを提案する.はじめに,最も電力の大きい基本波信号成分が共振しないリアクション型フィルタの基本動作を述べ,携帯電話基地局に適用する際の課題を検討する.次に,マイクロストリップ線路を用いた共振器のエッジ部での電流密度減少を可能とする分割オープンリング共振器を提案し,最大電流密度低減効果を電磁界シミュレーションにより示す.その結果を踏まえて,分割オープンリング共振器を適用した三次リアクション型フィルタを設計し,従来のパッチ型共振器を用いたデュアルモードフィルタよりも急しゅんな特性が得られ,耐電力特性向上が達成できることを解析により示し,本フィルタ方式の基本構成法及び実現可能性を検討する.
  • S. Futatsumori, T. Hikage, T. Nojima
    ELECTRONICS LETTERS 42 (7) 428 - 430 0013-5194 2006/03 [Refereed][Not invited]
     
    A microwave superconducting reaction-type filter consisting of novel split open-ring resonators is presented. Novel split open-ring resonators, which reduce the maximum current density while maintaining high Q-factors, are proposed. The frequency characteristics and Current distributions of the filter are investigated by the method of moments. The results predict that the filter realises both a higher power-handling capability and a better skirt property than existing high-temperature superconductor filters.
  • T Hikage, T Nojima, S Watanabe, T Shinozuka
    IEICE TRANSACTIONS ON COMMUNICATIONS E88B (8) 3281 - 3286 0916-8516 2005/08 [Refereed][Not invited]
     
    The electromagnetic field (EMF) distributions created inside a train carriage by the cellular radios of the passengers are analyzed and the impact their electromagnetic interference (EMI) on the implantable cardiac pacemakers is evaluated based upon the analysis results. Both computer simulations and experiments using 800 MHz and 2 GHz transmitters in an actual train carriage confirm that excessively high EMF, high enough to affect the normal functions of the pacemaker, does not occur inside the carriage provided the safe distance of 22 cm specified for pacemaker users is kept. A simplified histogram estimation method for electric field strength is newly developed to deal with the complicated EMF distributions. It allows the EMI risk to pacemakers by cellular radio transmission to be quantitatively evaluated. Methodologies are described first. Typical results of FDTD analysis and actual measurement data are then shown. Finally, considerations and conclusions are made.
  • Cavity-Backed Slot Antennas and Array with Simple Geometry Adapted to Microwave Energy Transmission
    Takashi Hikage, Kousuke Munakata, Toshio Nojima, Manabu Omiya, Kiyohiko Itoh
    U.R.S.I. The Radio Science Bulletin No.310 23 - 28 2004 [Refereed][Not invited]
  • KAWAMURA Teruo, YAMAMOTO Manabu, HIKAGE Takashi, ITOH Kiyohiko
    The transactions of the Institute of Electronics, Information and Communication Engineers. B 一般社団法人電子情報通信学会 J85-B (9) 1633 - 1643 1344-4697 2002/09 [Refereed][Not invited]
     
    無線LANシステムでは,マルチパスによる伝送品質の劣化が問題となる.このような劣化を回避する一手法として,マルチセクタアンテナの利用があげられる.設置の容易さなどを考慮すると,突起物のないアンテナを平面配置した平面マルチセクタアンテナを用いることが望ましい.そこで,本論文では,プリントスロット八木・宇田アレーアンテナで構成した平面マルチセクタアンテナを提案する.数値計算(スペクトル領域モーメント法及びFDTD法)を用いて,提案したアンテナの特性評価を行う.これにより,平面構造であるにもかかわらず,セクタ間の相互干渉が極めて小さなマルチセクタアンテナが実現可能であることを示す.また,19GHz帯において,提案したアンテナの試作測定を行い,数値計算による検討結果の妥当性を確認している.
  • T Hikage, M Omiya, K Itoh
    IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION 49 (12) 1712 - 1717 0018-926X 2001/12 [Refereed][Not invited]
     
    The finite-difference time-domain (FDTD) method is considered a versatile and efficient tool for the solution of Maxwell's equations in complex structures for any time dependence. In this paper, we show an antenna feed model suitable for performance evaluation of a cavity-backed slot antenna using the FDTD technique. The gap voltage and the coaxial feed models are examined, and their input characteristics and absolute gains are compared. Analytical results show that the input characteristics are estimated with fewer time steps for the coaxial model than for the conventional gap voltage model. Furthermore, we show how to calculate absolute gains and radiation patterns using the coaxial model and a sinusoidal voltage source at the desired frequency. The computed results of the absolute gain converge after the fifteenth period of the voltage source for the coaxial model and are in good agreement with the experimental results. On the other hand, the absolute gain is observed to fluctuate when the gap voltage model is used. The performance evaluation and comparison reveals that the coaxial model is an appropriate feed model for use in the analysis of the performance of the cavity-backed slot antenna using the FDTD technique. The good agreement of the FDTD results with the experimental measurements demonstrates the effectiveness of the model and the method proposed.
  • T Hikage, M Omiya, K Itoh
    ELECTRONICS AND COMMUNICATIONS IN JAPAN PART I-COMMUNICATIONS 84 (8) 70 - 77 8756-6621 2001 [Refereed][Not invited]
     
    By applying the FDTD method to the evaluation of the characteristics of a cavity-backed slot antenna, a design considering the feed structure is possible. In this paper, a feed model suitable for the design and analysis of a cavity-backed slot antenna is presented. As feed models, a gap voltage model and a coaxial model are used and results of their analysis are compared. From the analysis of the input characteristics, it is revealed that characteristic evaluation is possible in the coaxial model with fewer time steps than the gap voltage model. In the evaluation of the radiation characteristics, the absolute gain evaluation method is presented with a sinusoidal excitation. From the results of analysis of the absolute gain, the results converge within about 15 periods in the case of the coaxial model. The obtained radiation characteristics agree with the experimental results. In the gap voltage model, undulations of the absolute gain values are observed. From a comparison of these characteristic evaluations, the coaxial model is found to be suitable for FDTD analysis of a cavity-backed slot antenna. (C) 2001 Scripta Technica
  • HIKAGE Takashi, IMADA Mizuki, OMIYA Manabu, ITOH Kiyohiko
    The transactions of the Institute of Electronics, Information and Communication Engineers. B 一般社団法人電子情報通信学会 J82-B (10) 1905 - 1914 1344-4697 1999/10 [Refereed][Not invited]
     
    太陽発電衛星SPS2000では,送電アンテナ素子としてキャビティ付きスロットアンテナを使用することが提案されている.本論文においては,送電アンテナ素子の薄形化を目的として検討を行う.送電アンテナ素子として,終端短絡プローブ給電キャビティ付きスロットアンテナを使用する.このアンテナ素子では,キャビティ高さを低くした場合,キャビティ内部のプローブ位置,スロットの長さ及び幅を適当に設定することによって,送電周波数2.45GHzにおいてインピーダンス整合を実現することができる.本論文では,高さが12mm以下のキャビティ付きスロットアンテナについて,インピーダンス整合を実現する設計法とアンテナパラメータを示す.設計には時間領域差分(FDTD)法を使用し,解析結果と実験結果との比較検討を行う.これら検討から,提案した設計法の有効性を示す.更に,薄形化による特性変化について明らかにする.
  • HIKAGE Takashi, OMIYA Manabu, ITOH Kiyohiko
    The transactions of the Institute of Electronics, Information and Communication Engineers. B 一般社団法人電子情報通信学会 J82-B (5) 1038 - 1045 1344-4697 1999/05 [Refereed][Not invited]
     
    キャビティ付きスロットアンテナの特性評価にFDTD法を適用することで, 給電構造を考慮した設計が可能である. 本論文においては, キャビティ付きスロットアンテナの設計・解析に適した給電モデルを明らかにする. 給電モデルとしてギャップ電圧モデル及び同軸モデルを使用し, その解析結果を比較検討する. 入力特性解析結果から, 同軸モデルではギャップ電圧モデルに比較して少ないタイムステップ数で特性評価が可能であることを明らかにした. 放射指向特性評価では, 正弦波励振した場合の絶対利得評価法を示した. 絶対利得解析結果から, 同軸モデルでは15周期程度で値は収束し, その指向性は実験結果と一致すること, ギャップ電圧モデルでは絶対利得の値が振動する現象が観測されることを示した. これら特性評価比較結果から, キャビティ付きスロットアンテナのFDTD解析には, 給電モデルとして同軸モデルが適していることを明らかにした.
  • T Hikage, N Ohno, M Omiya, K Itoh
    ELECTRONICS AND COMMUNICATIONS IN JAPAN PART I-COMMUNICATIONS 82 (3) 20 - 27 8756-6621 1999/03 [Refereed][Not invited]
     
    A cavity-backed slot antenna is thought to be one of the most suitable elements for the wireless transmission of microwave energy, and especially for SPS2000, which was conceptually developed in Japan as a straw-man model of the solar power satellite. First, this paper presents the configuration and dimensions of the antenna element. Second, we propose a feeder geometry for which the above requirements are fulfilled and the desired antenna characteristics are obtained. The feeders are a short-ended probe and an inverted-F element whose dimensional parameters are examined experimentally and analytically. Here we use the FDTD technique developed in our previous study for the analysis of the cavity-backed slot antenna excited by these two kinds of feeder. (C) 1998 Scripta Technica.
  • T Hikage, M Omiya, K Itoh
    IEICE TRANSACTIONS ON ELECTRONICS E81C (12) 1838 - 1844 0916-8524 1998/12 [Refereed][Not invited]
     
    This paper discusses a method to evaluate mutual couplings of cavity-backed slot antennas using the FDTD technique. The antenna fed by the Short-ended probe is considered, which is investigated as an element of the power transmission antenna, Spacetenna, for the solar power satellite SPS2000. It is found from the FDTD computation on E-plane two- and four-element array antennas that the size of the problem space should be larger for the evaluation of the mutual coupling than for the estimation of the input impedance. Since enlarging the size of the problem space requires a large amount of computer storage, it is not practical for computer simulations. In order to carry out accurate estimations of the mutual coupling with relatively small amount of computer memory, the problem space is extended only in the broadside of the array antenna and in the other directions there are ten cells between the antenna surface and the outer boundary. Computer simulations demonstrate that there are no differences between the results of the proposed problem space geometry and the problem space extended in each direction of the axis coordinate by the same number of cells. Furthermore comparisons of computed and experimental results demonstrate the effectiveness of the approach after discussing how large the size of the problem space is required to estimate the mutual coupling.
  • M Omiya, T Hikage, N Ohno, K Horiguchi, K Itoh
    IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION 46 (12) 1853 - 1858 0018-926X 1998/12 [Refereed][Not invited]
     
    A cavity-backed slot antenna is thought to be one of the most suitable elements for the wireless transmission of microwave energy. A design technique is developed for the cavity-backed slot antenna using the finite-difference time-domain (FDTD) method. The technique is effective in characterizing antenna performance such as the input impedance and the far-field pattern since it takes into account the geometry of the feeder as well as the cavity. In this paper, we present a method that overcomes difficulties when the FDTD method is used to design the antenna. Moreover, we discuss how to determine the calculation parameters used in the FDTD analysis. Several numerical results are presented, along with measured data, which demonstrate the validity, efficiency, and capability of the techniques, The paper proposes a new prediction method for frequency characteristics of the cavity-backed slot antenna, which applies computational windows to time-sequence data. It is emphasized that windowing the slow decaying signal enables the extraction of accurate antenna characteristics. We also discuss how to estimate antenna patterns when we use a sinusoidal voltage excitation.
  • HIKAGE Takashi, OHNO Norio, OMIYA Manabu, ITOH Kiyohiko
    The transactions of the Institute of Electronics, Information and Communication Engineers 一般社団法人電子情報通信学会 J81-B-2 (3) 218 - 225 0915-1885 1998/03 [Refereed][Not invited]
     
    我が国において検討が行われている太陽発電衛星のストローマンモデルであるSPS2000では, 送電アンテナ素子としてキャビティ付きスロットアンテナの利用が提案されている.本論文においては, 初めに送電アンテナ素子に要求される寸法および構造条件を示す.更に, その条件を満足し, 所望のアンテナ特性を実現する給電構造について新たに提案を行う.給電方法として, 終端短絡ブローブ給電素子および逆F給電素子を用いることを提案し, その給電素子パラメータの決定法を解析および実験により明らかにする.但し, 給電構造を考慮したアンテナ特性の解析には, 筆者らによって明らかにされたFDTD解析手法を使用する.

Books etc

  • 空間伝送型ワイヤレス給電技術の最前線
    監修, 篠原真毅 (Contributor)
    シーエムシー出版 2021/05 (ISBN: 9784781316031)
  • Wireless Power Transfer: Theory, technology, and applications
    Naoki Shinohara (Contributor13 Impact of electromagnetic interference arising from wireless power transfer upon implantable medical device)
    IET (The Institution of Engineering and Technology) 2018/06 (ISBN: 9781785613463) 296
  • 監修, 篠原真毅 (Contributor8. ワイヤレス給電とEMC -ペースメーカを一例に-)
    シーエムシー出版 2016 (ISBN: 9784781311753)

Conference Activities & Talks

  • Mangseang Hor, Masanobu Hirose, Takashi Hikage
    IEEE Antennas and Propagation Society, AP-S International Symposium (Digest)  2023 
    In this paper, a 2×2 planar array of slot antennas for use in local 5G of 28 GHz frequency band is presented. The X-shaped slot antennas are used as radiating elements in the planar array. The feeding circuits of the planar array are conventional microstrip line and slot line. In this paper, antenna characteristics are evaluated by using the Finite Element Method in the commercial simulation software EMPro (Keysight). From the simulation results, -10 dB impedance bandwidth is obtained within the frequency range of 27.4 GHz to 30.5 GHz which is about 3.1 GHz bandwidth. The realized gain has the peak value of 14.6 dBi within 28.3 GHz to 28.5 GHz.
  • Mangseang Hor, Masanobu Hirose, Takashi Hikage
    2023 35th General Assembly and Scientific Symposium of the International Union of Radio Science, URSI GASS 2023  2023 
    In this paper, a slot antenna with wideband characteristics is newly designed and proposed for use in sub-6 local 5G band. The slot antenna is in the shape of X character. In this design, a microstrip line is electromagnetically coupled to the feeding point at the center portion of the slot antenna. A microstrip tapered line is used for impedance matching and connecting to the 50 Ω input port. Throughout this paper, the antenna characteristics are evaluated by using the Finite Element Method (FEM) in a commercial simulation software (EMPro). From simulation results, -10dB impedance bandwidth is obtained within 3.2 GHz to 5.1 GHz, which is about 1.9 GHz bandwidth and realized gain has a peak value of 11 dBi at 4.7 GHz.
  • Keiko Yamazaki, Naomi Tamura, Chihiro Miyashita, Toshio Yoshikawa, Atsuko Ikeda-Araki, Takashi Hikage, Manabu Omiya, Masahiro Mizuta, Miwa Ikuyo, Kazuhiro Tobita, Teruo Onishi, Masao Taki, Soichi Watanabe, Reiko Kishi
    2023 35th General Assembly and Scientific Symposium of the International Union of Radio Science, URSI GASS 2023  2023 
    We recorded Japanese children's exposure to radiofrequency electromagnetic fields (RF-EMF) using personal exposure meters from 2020 to 2021. There was no difference in the total exposure level during 2020 and 2021, in each recording place. However, the levels of each frequency bands were found to change between the recording years. The results suggest that the composition of the frequency bands to which children were exposed changed between 2020 and 2021 in Japan.
  • Kaito Sugimura, Takashi Hikage, Hiroshi Masuda, Tatsuya Ishitake, Kun Li, Akiko Nagai
    2023 IEEE International Symposium on Antennas and Propagation, ISAP 2023  2023 
    In order to study thermo-physiological reactions and changes in cellular functions of living animals and humans induced by millimeter-wave exposure, a novel localized exposure system at 60 GHz was developed using a spatial synthetic technique. We have confirmed that the exposure intensity at the desired area was sufficient to achieve desired temperature rise on the skin surface of living mice.
  • Funa Tsumura, Shuhei Waki, Takashi Hikage, Takahiro Iyama, Junji Higashiyama, Yasunori Suzuki
    2023 IEEE International Symposium on Antennas and Propagation, ISAP 2023  2023 
    In order to assess the interference effects in the micro/millimeter wave bands of the 5G, which is rapidly becoming popular in recent years, we have a newly developed monitoring tool for interference voltage induced in the pacemaker connector that can be used for a validation study of numerical simulations. We evaluated interference voltages under near-field exposure in 5G FR1 frequency bands.
  • Sakura Tsuruga, Manabu Omiya, Chihiro Miyashita, Kaito Sugimura, Keiko Yamazaki, Naomi Tamura, Takashi Hikage, Atsuko Ikeda-Araki, Reiko Kishi
    2023 IEEE International Symposium on Antennas and Propagation, ISAP 2023  2023 
    Due to the spread of smartphones and other wireless devices, and the decline in the age of starting to use these devices, children are increasingly exposed to RF-EMF. Therefore, it is required to conduct epidemiological research about the effect on children's health and RF exposure in the general environment. In this study, we precisely estimate the effects of human body blockage on personal exposure assessment tools in frequency bands, including 5G, using the FDTD method to investigate the dosimetry protocol for epidemiologic research.
  • Kohsuke Ushimaru, Takashi Hikage, Manabu Yamamoto, Manabu Omiya
    2023 IEEE International Symposium on Antennas and Propagation, ISAP 2023  2023 
    his study aims to investigate the propagation characteristics of private 5th-generation mobile communication system (5G) frequency bands, including the human body shadowing in indoor environments. We conducted a large-scale three-dimensional numerical analysis using the finite-difference time-domain (FDTD) method to model an indoor propagation environment containing humans and evaluate the propagation loss characteristics. The precise electric field distribution excited by a 5G transmitting antenna, which is used as the private-5 G access point, was calculated. Shadowing and scattering effects due to a real human body were evaluated in the full-wave simulations. Our simulation results show that the effect of reflected waves is significant for indoor radio propagation, and multipath fading increases significantly even though the loss due to human shielding is ameliorated.
  • Interference Voltage Measurement for EMI Evaluation of Active Implantable Medical Devices by Exposure to 4G and 5G Frequency Radio Waves using Electro-Optical Converter
    西川拓次, 日景隆, 井山隆弘, 東山潤司, 鈴木恭宜
    電子情報通信学会技術研究報告(Web)  2023
  • Estimation of Human Blockage Characteristics for Indoor Propagation in a Local-5G Frequency Band Using Large Scale FDTD Analysis
    吉田総希, 日景隆, 大宮学
    電子情報通信学会技術研究報告(Web)  2023
  • Performance Evaluation of 60 GHz Exposure Set-up for Study of Changes in Thermal Physiology and Cellular Mechanisms Induced by Localized Millimeter-wave Exposure
    山本康平, 日景隆, 増田宏, 石竹達也, LI Kun, 永井亜希子
    電子情報通信学会技術研究報告(Web)  2023
  • 子どものスクリーンタイムと聴覚・視覚ワーキングメモリーとの関連:北海道スタディ
    田村菜穂美, 山崎圭子, 宮下ちひろ, 池田敦子, 池田敦子, 日景隆, 水田正弘, 大宮学, 竹鼻美月, 赤坂梨莉花, 岸玲子
    日本衛生学雑誌(Web)  2023
  • 学童期の子どもの電磁波曝露実態の変化-北海道スタディ
    山崎圭子, 宮下ちひろ, 田村菜穂美, 池田敦子, 池田敦子, 日景隆, 水田正弘, 大宮学, 岸玲子
    日本衛生学雑誌(Web)  2023
  • Characteristics Estimation of 60 GHz Exposure Equipment for Investigation of Effects of Local Exposure to Millimeter-waves on Thermal Physiology and Cellular Functions
    杉村海渡, 敦賀桜, 日景隆, 増田宏, 石竹達也, LI Kun, 永井亜希子
    電子情報通信学会技術研究報告(Web)  2023
  • Experimental Assessment of Temperature Increase Due to Implanted Metal Plates under Combined Exposure of 4G and 5G Sub-6GHz Bands
    脇修平, 津村楓奈, 日景隆, 長岡智明
    電子情報通信学会技術研究報告(Web)  2023
  • A study on quasi-millimeter wave wideband slot array antenna with double-sided feeding circuit
    大野和輝, 日景隆, 山本学, 和井秀樹, 北直樹
    電子情報通信学会大会講演論文集(CD-ROM)  2023
  • Arrival Angle Dependency of SAR Enhancement Characteristics Due to Implanted Metal Plates Exposed to Plane Waves
    脇修平, 西川拓次, 日景隆, 長岡智明
    電子情報通信学会大会講演論文集(CD-ROM)  2023
  • Evaluation of 60 GHz Exposure Equipment for Investigation of Effects of Local Exposure to Millimeter-waves on Thermal Physiology and Cellular Functions
    杉村海渡, 敦賀桜, 日景隆, 増田宏, 石竹達也, LI Kun, 永井亜希子
    電子情報通信学会技術研究報告(Web)  2023
  • Characteristics of Human Body Shadowing Considering Elevation Angle in 5G Frequency Band for Epidemiological Research on RF Exposure and Children’s Health
    敦賀桜, 杉村海渡, 日景隆, 大宮学, 山崎圭子, 宮下ちひろ, 田村奈穂美, 池田敦子, 岸玲子
    電子情報通信学会技術研究報告(Web)  2023
  • Numerical Estimation of Temperature Increase Due to Implanted Metal Plates Under Radio Frequency Exposure of 4G/LTE Frequency Bands
    脇修平, 津村楓奈, 日景隆, 長岡智明
    電子情報通信学会技術研究報告(Web)  2023
  • Characteristics Evaluation of Wideband Slot Array Antenna with Slitted Reflector by Prototype Measurement
    大野和輝, 日景隆, 山本学, 和井秀樹, 北直樹
    電子情報通信学会技術研究報告(Web)  2023
  • EM Wave Exposure Assessment Technology for Human Bodies: 5: Experimental Investigation of SAR Enhancement Due to Implant Metal Exposed to External Electromagnetic Waves
    日景隆
    情報通信研究機構研究報告  2023
  • Estimation of the Perceptual Temperature Rise for Localized Electromagnetic Exposure at 28 GHz
    新井紀香, 小寺紗千子, 上原信太郎, 湯浅明子, 牛澤一樹, 大高洋平, 日景隆, 平田晃正
    電子情報通信学会技術研究報告(Web)  2023
  • Numerical Estimation of Specific Absorption Rates in Vertical Upward Exposures Using Various Anatomical Human Body Models
    篭橋みのり, 日景隆, 山本学
    電子情報通信学会技術研究報告(Web)  2023
  • 4G/LTE周波数帯の遠方界ばく露における医療用埋込金属プレート近傍のSAR上昇推定—Numerical Estimation of SAR Enhancement Due to Implanted Metal Plates Exposed to Far-Field at 4G/LTE Frequency Bands—電磁環境 半導体電力変換合同研究会・半導体電力変換,EMC一般
    脇 修平, 西川 拓次, 日景 隆, 長岡 智明
    電気学会研究会資料. SPC = The papers of technical meeting on semiconductor power converter, IEE Japan / 半導体電力変換研究会 [編]  2022/12
  • 医療・福祉分野のデジタルトランスフォーメーションを支える電波の植込み型医療器EMI評価技術
    日景 隆, 脇 修平, 西川 拓次
    Precision Medicine  2022/08  (株)北隆館
     
    医療・福祉分野で進むデジタルトランスフォーメーション(DX)を支える電波利用に対する体内植込み型医療機器(心臓ペースメーカ/ICD)の電磁干渉影響(EMI)とその評価法について概説する。第5世代移動通信システムやワイヤレス電力伝送装置など、新たな電波利用がDXを加速させる状況において、電波機器の利用者、植込み型医療機器などの装着者、双方の機器の製造者などが影響の発生・防止に関する情報を共有し、影響防止に努めていくことが重要である。(著者抄録)
  • 山崎 圭子, 田村 菜穂美, 宮下 ちひろ, 池田 敦子, 福永 久典, 日景 隆, 水田 正弘, 大宮 学, 岸 玲子
    日本衛生学雑誌  2022/03  (一社)日本衛生学会
  • 田村 菜穂美, 山崎 圭子, 宮下 ちひろ, 池田 敦子, 福永 久典, 日景 隆, 水田 正弘, 大宮 学, 岸 玲子
    日本衛生学雑誌  2022/03  (一社)日本衛生学会
  • 宮下 ちひろ, 山崎 圭子, 田村 菜穂美, 池田 敦子, 福永 久典, 日景 隆, 水田 正弘, 大宮 学, 岸 玲子
    日本衛生学雑誌  2022/03  (一社)日本衛生学会
  • Evaluation of Aircraft Cabin- to-Exterior Propagation Characteristics for 4 GHz-band WAIC Systems using a Large Scale FDTD Analysis
    関口徹也, 日景隆, 山本学, 野島俊雄, 二ッ森俊一, 森岡和行, 河村暁子, 米本成人
    電子情報通信学会技術研究報告(Web)  2022
  • A Study on FDTD Simulation of Lens Antennas for Spatial Synthetic Exposure System
    尾崎龍之介, 山本尚也, 日景隆
    電子情報通信学会技術研究報告(Web)  2022
  • Estimation of Human Body Blockage Effects on Portable Exposure Meter for Epidemiological Studies on Radio Wave Exposure and Health Effects in Adolescents
    山本康平, 日景隆, 大宮学, 山崎圭子, 池田敦子, 宮下ちひろ, 田村菜穂美, 岸玲子
    電子情報通信学会大会講演論文集(CD-ROM)  2022
  • Numerical Estimation of SAR Enhancement Due to Implanted Metal Plates Exposed to Far-Field at 4G/LTE Frequency Bands
    脇修平, 西川拓次, 日景隆, 長岡智明
    電子情報通信学会技術研究報告(Web)  2022
  • A Study on Miniaturized Patch Antenna with Circular Polarization for Earth Sensing Platform via LEO Satellite
    大友啓暉, 日景隆, 山本学, 坂元一光, 藤野洋輔
    電子情報通信学会技術研究報告(Web)  2022
  • Estimation of Electromagnetic Coupling Due to Lead on Pacemaker EMI in Cellular Frequency Band
    西川拓次, 日景隆, 山本学
    電気・情報関係学会北海道支部連合大会講演論文集(CD-ROM)  2022
  • A fundamental study on miniaturized patch antenna with L-probe feed and circular polarization
    大友啓暉, 日景隆, 山本学
    電気・情報関係学会北海道支部連合大会講演論文集(CD-ROM)  2022
  • Numerical Estimation of SAR Enhancement Due to Implanted Metal Plates Exposed to Circularly Polarized Wave
    脇修平, 西川拓次, 日景隆, 長岡智明
    電気・情報関係学会北海道支部連合大会講演論文集(CD-ROM)  2022
  • Fundamental study on quasi-millimeter wave band slot array antenna with double-sided feeding circuit
    大野和輝, 日景隆, 山本学
    電気・情報関係学会北海道支部連合大会講演論文集(CD-ROM)  2022
  • Estimation of Human Body Blockage Characteristics Considering Elevation Angle of Plane-wave for RF Dosimetry of Adolescent
    杉村海渡, 山本康平, 日景隆, 山崎恵子, 宮下ちひろ, 田村菜穂美, 荒木敦子, 岸玲子
    電気・情報関係学会北海道支部連合大会講演論文集(CD-ROM)  2022
  • Large-scale FDTD Analysis for Optimal Wireless Link Design of Local 5G in Real Indoor Propagation Environment
    吉田総希, 日景隆, 山本学, 大宮学
    電気・情報関係学会北海道支部連合大会講演論文集(CD-ROM)  2022
  • 子どものスクリーンタイムおよび問題行動との関連:北海道スタディ
    田村菜穂美, 山崎圭子, 宮下ちひろ, 池田敦子, 池田敦子, 福永久典, 日景隆, 水田正弘, 大宮学, 岸玲子
    日本衛生学雑誌(Web)  2022
  • 学童期における携帯電話等の電磁波曝露の実態調査-北海道スタディ
    山崎圭子, 田村菜穂美, 宮下ちひろ, 池田敦子, 池田敦子, 福永久典, 日景隆, 水田正弘, 大宮学, 岸玲子
    日本衛生学雑誌(Web)  2022
  • 小児の携帯情報端末の使用開始年齢と問題行動の程度との関連-北海道スタディ
    宮下ちひろ, 山崎圭子, 田村菜穂美, 池田敦子, 池田敦子, 福永久典, 日景隆, 水田正弘, 大宮学, 岸玲子
    日本衛生学雑誌(Web)  2022
  • Characterization of Human Body Blockage in Cellular and Wireless LAN Frequency Bands for Epidemiologic Research on Association Between Radio Frequency Wave Exposure and Children Health
    山本康平, 杉村海渡, 日景隆, 大宮学, 山崎圭子, 宮下ちひろ, 田村奈穂美, 池田敦子, 岸玲子
    電子情報通信学会技術研究報告(Web)  2022
  • Estimation on Human Body Blockage Characteristics of Child Model for Epidemiologic Research on RF Exposure and Adolescent Health
    杉村海渡, 山本康平, 日景隆, 大宮学, 山崎圭子, 宮下ちひろ, 田村奈穂美, 池田敦子, 岸玲子
    電子情報通信学会技術研究報告(Web)  2022
  • Estimation of Exposure Polarization Dependent Characteristics of Active Implantable Medical Device EMI in 5G Sub-6 Frequency Band
    西川拓次, 日景隆, 井山隆弘, 東山潤司, 鈴木恭宜
    電子情報通信学会技術研究報告(Web)  2022
  • Active Implantable Medical Device EMI Estimation for EV-Charging WPT Systems
    脇修平, 西川拓次, 日景隆
    電子情報通信学会技術研究報告(Web)  2022
  • FDTD Simulation for Specific Absorption Rate Enhancement Due to Metallic Plate Implants with Screw Holes at Mobile Radio Frequency Bands
    西川拓次, 日景隆, 長岡智明
    電子情報通信学会技術研究報告(Web)  2022
  • A Study on Gain Reduction Suppression in a Wideband Slot Array Antenna with a Reflector
    山本尚也, 日景隆, 山本学, 和井秀樹, 岩國辰彦, 内田大誠, 北直樹
    電子情報通信学会技術研究報告(Web)  2022
  • Measurement of Temperature Rise due to RF Exposure Around Implanted Metal Plates for Mandibular Fracture Fixation
    西川拓次, 大塚敦生, 日景隆, 長岡智明
    電子情報通信学会大会講演論文集(CD-ROM)  2022
  • Estimation of Indoor Propagation Characteristics Considering Human Blockage at 5G Frequency Band Using Parallelized FDTD Analysis
    吉田総希, 日景隆, 山本学, 久野伸晃, 猪又稔, 山田渉
    電子情報通信学会大会講演論文集(CD-ROM)  2022
  • A study on a wideband rectangular loop antenna backed by a periodic patch-loaded grounded slab
    大友啓暉, 日景隆, 山本学
    電子情報通信学会大会講演論文集(CD-ROM)  2022
  • FEM Simulation of induced interference voltage of implantable medical devices near dipole and slot antennas in 5G sub6 frequency band
    大塚敦生, 西川拓次, 日景隆, 井山隆弘, 東山潤司, 鈴木恭宜
    電子情報通信学会技術研究報告(Web)  2022
  • 日景 隆, 大塚 敦生, 西川 拓次
    地域ケアリング / 地域ケアリング企画編集委員会 編  2021/08  北隆館
  • 日景 隆, 大塚 敦生, 西川 拓次
    Bio clinica = バイオクリニカ  2021/07
  • 電波へのばく露による児の精神神経発達への影響に関する最近の研究動向 文献調査
    山崎 圭子, 荒木 敦子, 田村 菜穂美, 寺岡 友里, 日景 隆, 水田 正弘, 大宮 学, 岸 玲子
    北海道公衆衛生学雑誌  2021/03  北海道公衆衛生学会
     
    近年、電波ばく露環境は急速に変化していると考えられ、子どもの健康、特に精神神経発達への影響が懸念される。本研究の目的は、胎児期と出生後のばく露による子どもの精神神経発達への影響について先行研究を概観し、今後の研究の方向性を明らかにすることである。胎児期ばく露を扱った7編のうち3編で妊娠中の母の携帯電話使用状況と精神神経発達の間に負の関連が、1編で正の関連が報告されていた。出生後のばく露を扱った22編では、2編を除き、携帯電話使用状況または電波ばく露レベルと精神神経発達との負の関連が報告されていた。今後の研究では、携帯電話や電子機器の使用状況と電波ばく露による影響を独立に検討する必要がある。また、因果関係を考察するために適した前向き研究デザインを用いることが望ましい。さらに電波ばく露の背後にある交絡要因についても慎重に検討する必要がある。(著者抄録)
  • Design of Planar-Type Wideband Array Antenna Using Double-Sided Feeding Circuit and Leaf-Shaped Bowtie Slot Element
    山本尚也, 日景隆, 山本学
    電子情報通信学会技術研究報告(Web)  2021
  • Numerical Estimation of Indoor/Outdoor Multipath Propagation Characteristics Using a Large-Scale FDTD Analysis
    日景隆, 大宮学
    電子情報通信学会技術研究報告(Web)  2021
  • Assessment technique for active implantable medical device EMI for new wireless IoT devices
    日景隆, 大塚敦生, 西川拓次
    地域ケアリング  2021
  • Interference Path Loss Measurements at 4 GHz Radio Altimeter Band Based on Twin Turboprop Aircraft-Evaluations Using Beechcraft B300 aircraft-
    二ッ森俊一, 宮崎則彦, 日景隆, 関口徹也, 山本学, 野島俊雄
    電子情報通信学会技術研究報告(Web)  2021
  • Estimation on Human Body Blockage Characteristics at 5G Sub-6GHz Frequency bands for Epidemiologic Research on RF Exposure and Adolescent Health
    山本康平, 尾崎龍之介, 日景隆, 山崎圭子, 宮下ちひろ, 岸玲子
    電子情報通信学会技術研究報告(Web)  2021
  • Development of Novel 60 GHz Band Spatial Synthetic Exposure Set-up for Studies on Thermal Perception Thresholds of Biological Effects
    尾崎龍之介, 日景隆, 増田宏, 田口健治
    電子情報通信学会技術研究報告(Web)  2021
  • Interference-induced Voltage Estimation for Implantable Medical Devices Due to Near Field Exposure from Electric and Magnetic Antennas
    大塚敦生, 日景隆, 石岡諒汰, 東山潤司, 鈴木恭宜
    電子情報通信学会技術研究報告(Web)  2021
  • Evaluation of Cabin- to-Exterior Propagation Characteristics for Sub-6GHz/5G using Small Aircraft Model
    佐藤亜衣, 日景隆, 大宮学, 二ッ森俊一, 河村暁子, 米本成人
    電子情報通信学会技術研究報告(Web)  2021
  • Novel assessment technique for active implantable medical device EMI due to new wireless equipments
    日景隆, 大塚敦生, 西川拓次
    Bio Clinica  2021
  • A Study of Acceleration Method for Estimation on Propagation Characteristics in an Urban Environment Using Large-scale FDTD Analysis
    佐藤亜衣, 吉江明花, 日景隆, 山本学, 大宮学, 久野伸晃, 猪又稔, 山田渉
    電子情報通信学会大会講演論文集(CD-ROM)  2021
  • Radio Altimeter Interference Pass Loss of Small Size Aircraft-Measurement and Evaluation Including Adjacent Frequency Bands using Beechcraft B300 Aircraft-
    二ッ森俊一, 宮崎則彦, 佐藤亜衣, 尾崎龍之介, 日景隆, 野島俊雄
    電子情報通信学会大会講演論文集(CD-ROM)  2021
  • A Study on a Leaf-Shaped Bowtie Slot Array Antenna Using Double-Sided Feeding Circuits
    山本尚也, 日景隆, 山本学
    電子情報通信学会大会講演論文集(CD-ROM)  2021
  • Interference Voltage Measurement Using an Electro-Optic Converter for Estimation of Implantable Cardiac Pacemaker EMI for 5G/Sub-6 GHz
    日景隆, 大塚敦生, 石岡諒汰, 東山潤司, 鈴木恭宜
    電子情報通信学会大会講演論文集(CD-ROM)  2021
  • A Study on Simulation Accuracy for Numerical estimation of Indoor Multipath Propagation Characteristics Using a Large-Scale FDTD Analysis
    吉江明花, 佐藤亜衣, 日景隆, 山本学, 大宮学, 久野伸晃, 猪又稔, 山田渉
    電子情報通信学会技術研究報告(Web)  2021
  • Numerical Estimation on Active Implantable Medical Device EMI Due to 5G Sub6 Frequency band Using Finite Element Analysis
    SUN Jintao, 伊藤涼音, 日景隆
    電子情報通信学会技術研究報告(Web)  2021
  • Evaluation of Aircraft Cabin- to-Exterior Propagation Characteristics for Sub-6GHz/5G using a Large Scale FDTD Analysis
    佐藤亜衣, 吉田総希, 日景隆, 二ッ森俊一, 河村暁子, 米本成人
    電子情報通信学会技術研究報告(Web)  2021
  • Estimation on Frequency Characteristics of SAR Elevation Due to Mandibular Treatment Plate Implantation
    伊藤涼音, 大塚敦生, 日景隆, 長岡智明, 和氣加奈子
    電子情報通信学会技術研究報告(Web)  2021
  • 電波へのばく露による児の精神神経発達への影響に関する最近の研究動向:文献調査
    山崎圭子, 荒木敦子, 田村菜穂美, 寺岡友里, 日景隆, 水田正弘, 大宮学, 岸玲子
    北海道公衆衛生学雑誌  2021
  • 山崎 圭子, 荒木 敦子, 寺岡 友里, 日景 隆, 水田 正弘, 大宮 学, 岸 玲子
    日本衛生学雑誌  2020/03  (一社)日本衛生学会
  • 荒木 敦子, 山崎 圭子, 寺岡 友里, 日景 隆, 水田 正弘, 大宮 学, 岸 玲子
    日本衛生学雑誌  2020/03  (一社)日本衛生学会
  • Numerical Estimation of RF Leakage Wave Characteristics in WAIC Frequency Band using FDTD Simulation
    関口徹也, 日景隆, 山本学, 二ッ森俊一, 森岡和行, 河村暁子, 米本成人
    電気・情報関係学会北海道支部連合大会講演論文集(CD-ROM)  2020
  • Measurement of Temperature Rise Around Gap of Implanted Metal Plates with Screw Holes
    伊藤涼音, 日景隆, 山本学, 長岡智明, 和氣加奈子, 渡辺聡一
    電気・情報関係学会北海道支部連合大会講演論文集(CD-ROM)  2020
  • Interference Voltage Measurement Set-up for Estimation of Implantable Cardiac Pacemaker EMI for Sub6GHz of IMT-2020
    大塚敦生, 日景隆, 山本学
    電気・情報関係学会北海道支部連合大会講演論文集(CD-ROM)  2020
  • Characteristics Evaluation of Rectangular Loop Antenna Backed by EBG Reflector
    鴫原達郎, 日景隆, 山本学
    電気・情報関係学会北海道支部連合大会講演論文集(CD-ROM)  2020
  • Development of Novel 60 GHz Spatial Power Combining Exposure Set-up for Studies on Thermal Perception Thresholds of Biological Effects Exposed to mm-Wave
    尾崎龍之介, 日景隆, 山本学, 増田宏
    電気・情報関係学会北海道支部連合大会講演論文集(CD-ROM)  2020
  • Numerical Estimations of Specific Absorption Rates for 920MHz-band RFID Using Anatomical Phantom Models of Different Age and Gender
    木村凌太, 日景隆, 山本学
    電気・情報関係学会北海道支部連合大会講演論文集(CD-ROM)  2020
  • A Study of Estimation Accuracy on Propagation Characteristics in an Urban Environment Using Commercial Software of Ray-tracing
    吉江明花, 日景隆, 山本学
    電気・情報関係学会北海道支部連合大会講演論文集(CD-ROM)  2020
  • A Study of Safety Exposure Assessment for Multi-hop Magnetic Resonance Wireless Power Transfer System
    大勝隆平, 日景隆, 山本学
    電気・情報関係学会北海道支部連合大会講演論文集(CD-ROM)  2020
  • Numerical Estimation on Received Power Distribution of RF Propagation in an Urban Environment Using FDTD simulation
    佐藤亜衣, 日景隆, 大宮学, 山本学
    電気・情報関係学会北海道支部連合大会講演論文集(CD-ROM)  2020
  • A 16-element Leaf-Shaped Bowtie Slot Array Antenna Using Double-Sided Feeding Circuits
    山本尚也, 日景隆, 山本学
    電気・情報関係学会北海道支部連合大会講演論文集(CD-ROM)  2020
  • Numerical Estimation on Interference Voltage at Implantable Cardiac Pacemaker Due to Near-field Exposure from Slot Antenna Using Finite Element Analysis
    SUN Jintao, 日景隆, 山本学
    電気・情報関係学会北海道支部連合大会講演論文集(CD-ROM)  2020
  • A Leaf-Shaped Bowtie Slot Array Antenna Using Double-Sided Feeding Circuits
    山本尚也, 日景隆, 山本学
    電子情報通信学会大会講演論文集(CD-ROM)  2020
  • Aircraft Electric Field Strength Evaluations at 4 GHz Wireless Avionics Intra-Communications Band-Measurement of Ground Radiation Characteristics Using Beechcraft B300 Aircraft-
    二ッ森俊一, 宮崎則彦, 関口徹也, 日景隆, 野島俊雄
    電子情報通信学会大会講演論文集(CD-ROM)  2020
  • Estimation on Human Body Blockage Characteristics at 5G Frequency Bands for Epidemiologic Research on RF Exposure and Adolescent Health
    尾崎龍之介, 日景隆, 大宮学, 水田正弘, 山崎圭子, 荒木敦子, 岸玲子
    電子情報通信学会大会講演論文集(CD-ROM)  2020
  • Estimation of Specific Absorption Rate Around Gap of Implanted for Mandibular Fracture Fixation Metal Plates with Screw Holes
    伊藤涼音, 大塚敦生, 日景隆, 長岡智明, 和氣加奈子, 渡辺聡一
    電子情報通信学会大会講演論文集(CD-ROM)  2020
  • 伊藤涼音, SUN Jintao, 日景隆, 東山潤司, 大西輝夫
    電子情報通信学会技術研究報告  2019/07
  • 関口徹也, 日景隆, 山本学, 野島俊雄, 大宮学, 二ッ森俊一, 森岡和行, 河村暁子, 米本成人
    電子情報通信学会技術研究報告  2019/07
  • 二ッ森俊一, 森岡和行, 河村暁子, 米本成人, 日景隆, 関口徹也, 野島俊雄
    電子航法研究所研究発表会講演概要  2019/06
  • 吉江明花, 榊原慶太, 日景隆
    電子情報通信学会技術研究報告  2019/06
  • 日景隆, SON Shinto, 野島俊雄
    電子情報通信学会技術研究報告  2019/06
  • Shunichi Futatsumori, Kazuyuki Morioka, Takashi Hikage, Tetsuya Sekiguchi, Manabu Yamamoto, Toshio Nojima
    2019 International Applied Computational Electromagnetics Society Symposium in Miami, ACES-Miami 2019  2019/05 
    © 2019 ACES. Wireless avionics intra-communication (WAIC) systems are operated at the same frequency bands as aircraft radio altimeters, i.e., 4,200-4,400 MHz. The coexistence conditions of WAIC systems and radio altimeters are investigated in detail with respect to electromagnetic compatibility. Firstly, the 4-GHz electromagnetic field around a three-dimensional Airbus A320 aircraft model is obtained through large-scale finite-difference time-domain analysis. Then, a transmitting antenna is modeled at the center of the aircraft at window height. Finally, the point source transmitting power at the geometrical center of the aircraft is estimated for the coexistence investigation.
  • 吉江明花, 山岸誠知, 日景隆
    電子情報通信学会大会講演論文集(CD-ROM)  2019/03
  • 関口徹也, 日景隆, 山本学, 野島俊雄, 二ッ森俊一, 森岡和行, 河村暁子, 米本成人
    電子情報通信学会大会講演論文集(CD-ROM)  2019/03
  • 伊藤涼音, 松田映美, 日景隆, 野島俊雄, 長岡智明, 渡邊聡一
    電子情報通信学会大会講演論文集(CD-ROM)  2019/03
  • 吉江明花, 山岸誠知, 日景隆, 久野伸晃, 中村光貴, 山田渉, 鷹取泰司
    電子情報通信学会大会講演論文集(CD-ROM)  2019/03
  • 佐藤彰弘, 緒方大悟, 木村翔, 表英毅, 日景隆
    電子情報通信学会大会講演論文集(CD-ROM)  2019/03
  • Shinto Son, Emi Matsuda, Takashi Hikage, Toshio Nojima
    2019 URSI Asia-Pacific Radio Science Conference, AP-RASC 2019  2019/03 
    © 2019 URSI. All rights reserved. With regard to the electromagnetic field (EMF) emitted from wireless communication devices, international radio radiation protection guidelines for human exposure to EMF have been established by the International Commission on Non-Ionizing Radiation Protection (ICNIRP) [1] and the Institute of Electrical and Electronic Engineers (IEEE) [2]. These guidelines provide no quantitative discussions about their relevance to humans with metallic objects embedded in their bodies. It is very important to estimate the amount of exposure that users with metallic implants will experience. Some papers regarding interaction of radio frequency (RF) EMF and metallic implants have been published, and studies on the EMF exposure of users with passive metallic implants have reported measurements and numerical estimations [3], [4].
  • T. Sekiguchi, T. Hikage, S. Futatsumori, A. Kohmura, N. Yonemoto
    2018 USNC-URSI Radio Science Meeting (Joint with AP-S Symposium), USNC-URSI 2018 - Proceedings  2019/01 
    © 2018 IEEE. Aim of this study is to develop an accurate and reliable method for estimating propagation characteristics inside and outside aircraft cabin so as to advance wireless link design for Wireless Avionics Intra-Communication (WAIC) system. This paper estimates propagation characteristics from inside cabin to exterior mounted antenna of WAIC system installed on a passenger aircraft (Airbus 320-200 model). EMF distributions excited by a 4.4 GHz wireless transmitter inside cabin are analyzed and fundamental characteristics for the WAIC system are derived from the analysis results.
  • Masakazu Yamagishi, Takashi Hikage, Motoharu Sasaki, Mitsuki Nakamura, Yasushi Takatori
    2018 48th European Microwave Conference, EuMC 2018  2018/11 
    © 2018 European Microwave Association. The aim of this study is to develop an accurate and reliable method of estimating propagation channels and propagation modelling so as to advance radio link design of fifth generation (5G) wireless systems. It was reported that in the high frequency bands used for 5G, shadow fading is large as is the loss due to human bodies. This paper elucidates the effects of human body blockage on 26 GHz-band propagation characteristics in an indoor environment. A novel method for estimating human body blockage characteristics based on large scale FDTD analysis is proposed. Electromagnetic field distributions inside an office environment created by a 26 GHz wireless transmitter are analysed and propagation characteristics are discussed.
  • Emi Matsuda, Keita Sakakibara, Takashi Hikage, Manabu Yamamoto, Toshio Nojima
    2018 IEEE International Workshop on Electromagnetics: Applications and Student Innovation Competition, iWEM 2018  2018/11 
    © 2018 IEEE. The RF exposure guidelines do recognize that an increased local SAR (Specific Absorption Rate) due to metallic implants is possible. In this study, the effect of implantable medical device in human torso region is examined. A simple flat torso phantom is used which a cardiac pacemaker model is implanted in. The local SAR dependencies due to exposure frequency bands were presented. Here, we estimate localized SAR at several candidate frequency bands for 5th generation wireless systems.
  • 日景隆, 松田映美, 山岸誠知, 東山潤司, 大西輝夫
    電子情報通信学会技術研究報告  2018/11
  • 松田映美, 日景隆, 山本学, 野島俊雄, 長岡智明, 渡邊聡一
    電気・情報関係学会北海道支部連合大会講演論文集(CD-ROM)  2018/10
  • 榊原慶太, 関口徹也, 日景隆
    電気・情報関係学会北海道支部連合大会講演論文集(CD-ROM)  2018/10
  • 山岸誠知, 日景隆, 山本学, 野島俊雄
    電気・情報関係学会北海道支部連合大会講演論文集(CD-ROM)  2018/10
  • 関口徹也, 日景隆, 山本学, 大宮学, 二ッ森俊一, 森岡和行, 河村暁子, 米本成人
    電気・情報関係学会北海道支部連合大会講演論文集(CD-ROM)  2018/10
  • 日景隆, 山岸誠知, 飴谷充隆, 黒川悟
    電気・情報関係学会北海道支部連合大会講演論文集(CD-ROM)  2018/10
  • 山岸 誠知, 日景 隆, 久野 伸晃, 中村 光貴, 山田 渉, 鷹取 泰司
    電子情報通信学会技術研究報告 = IEICE technical report : 信学技報  2018/09
  • 松田映美, 日景隆, 山本学, 野島俊雄, 長岡智明, 渡邊聡一
    電子情報通信学会大会講演論文集(CD-ROM)  2018/08
  • 二ッ森俊一, 宮崎則彦, 関口徹也, 日景隆, 野島俊雄
    電子情報通信学会大会講演論文集(CD-ROM)  2018/08
  • 山岸 誠知, 日景 隆, 榊原 慶太, 野島 俊雄
    電気学会研究会資料. SPC = The papers of technical meeting on semiconductor power converter, IEE Japan  2018/07
  • 山岸誠知, 日景隆, 榊原慶太, 野島俊雄
    電子情報通信学会技術研究報告  2018/06
  • 松田映美, 日景隆, 野島俊雄
    電子情報通信学会技術研究報告  2018/06
  • 榊原慶太, 日景隆, 山岸誠知
    電子情報通信学会技術研究報告  2018/06
  • Futatsumori Shunichi, Morioka Kazuyuki, Kohmura Akiko, Yonemoto Naruto, Hikage Takashi, Sekiguchi Tetsuya, Yamamoto Manabu, Nojima Toshio
    IEEE Conference Proceedings  2018/05 
    ? 2018 Applied Computational Electromagnetics Society (ACES). Radio altimeters and wireless avionics intra-communication (WAIC) systems are both operated at the frequency band 4,200 MHz-4,400 MHz. Hence, a detailed analysis is required for spectrum sharing in the same band. Firstly, a large-scale finite-difference time-domain analysis is performed to obtain the detailed characteristics of the electromagnetic field (EMF) around the three-dimensional Airbus A320 aircraft model, which assumes that a WAIC device is located inside the cabin. Then, the 4-GHz EMF propagation characteristics are evaluated based on the analyzed results. Finally, the methodology of the interference analysis is discussed based on the obtained EMF characteristics.
  • 誘電体板付加によるパッチアレーアンテナの高利得化に関する基礎検討  [Not invited]
    蒔苗匠馬, 本橋諄平, 日景隆, 山本学, 平賀健, 内田大誠
    電子情報通信学会大会講演論文集(CD-ROM)  2018/03
  • 積雪中に埋もれた人体に装着した携帯端末の電波伝搬特性  [Not invited]
    表英毅, 藤井輝也, 日景隆
    電子情報通信学会大会講演論文集(CD-ROM)  2018/03
  • FDTD解析を用いた26GHz帯での人体遮蔽特性推定  [Not invited]
    山岸誠知, 日景隆, 佐々木元晴, 中村光貴, 鷹取泰司
    電子情報通信学会大会講演論文集(CD-ROM)  2018/03
  • 携帯電話周波数帯におけるネジ穴を考慮した埋め込み金属プレートによるSAR上昇推定  [Not invited]
    松田映美, 日景隆, 山本学, 野島俊雄, 長岡智明, 渡邊聡一
    電子情報通信学会大会講演論文集(CD-ROM)  2018/03
  • 大規模FDTD解析を用いた4.4GHz帯機外WAICシステム設計のための伝搬特性推定  [Not invited]
    関口徹也, 日景隆, 山本学, 野島俊雄, 二ッ森俊一, 河村暁子, 米本成人
    電子情報通信学会大会講演論文集(CD-ROM)  2018/03
  • Temperature Increase on Implantable Medical Device Inside Human Body Due to External Electromagnetic Waves : HF-WPT and 5G Cellular Frequency Bands  [Not invited]
    日景 隆, 大勝 隆平, 井山 隆弘, 大西 輝夫
    電子情報通信学会技術研究報告 = IEICE technical report : 信学技報  2018/03
  • Temperature Increase on Implantable Medical Device Inside Human Body Due to External Electromagnetic Waves: HF-WPT and 5G Cellular Frequency Bands-  [Not invited]
    日景隆, 大勝隆平, 井山隆弘, 大西輝夫
    電子情報通信学会技術研究報告  2018/02
  • Evaluation of Aircraft Cabin- to-Exterior Propagation Characteristics for 4.4 GHz-band WAIC Systems using a Large Scale FDTD Analysis  [Not invited]
    関口 徹也, 日景 隆, 山本 学, 野島 俊雄, 二ッ森 俊一, 河村 暁子, 米本 成人
    電子情報通信学会技術研究報告 = IEICE technical report : 信学技報  2018/01
  • Evaluation of Aircraft Cabin-to-Exterior Propagation Characteristics for 4.4GHz-band WAIC Systems using a Large Scale FDTD Analysis  [Not invited]
    関口徹也, 日景隆, 山本学, 野島俊雄, 二ッ森俊一, 河村暁子, 米本成人
    電子情報通信学会技術研究報告  2018/01
  • Microwave electromagnetic field characteristic evaluations in aircrafts containing lossy materials based on quality factor of a reverberation chamber  [Not invited]
    Shunichi Futatsumori, Takashi Hikage
    2017 International Symposium on Antennas and Propagation, ISAP 2017  2017/12 
    ? 2017 IEEE. The effects of electromagnetic lossy materials such as humans, on the electromagnetic field (EMF) characteristics of an aircraft are evaluated using finite-difference time-domain analyses and experiments conducted in a reverberation chamber. This study aims to confirm the EMF reduction effect, through measurements. The results of a large-scale finite-difference time-domain analysis conducted on a model of the B777-200 aircraft with occupants show a reduction in the electric field strength inside the cabin. The EMF loss due to a human phantom is measured quantitatively using a reverberation chamber, between 500 MHz and 6 GHz. The measured quality factor is found to be reduced by 55% when using a full-sized human phantom, which is lower than of the value measured at 2.1 GHz, without using a phantom.
  • 大規模FDTD解析を用いた機外WAICシステムの4.4GHz帯電波伝搬特性推定  [Not invited]
    関口徹也, 日景隆, 山本学, 野島俊雄, 二ッ森俊一, 河村暁子, 米本成人
    電気・情報関係学会北海道支部連合大会講演論文集(CD-ROM)  2017/10
  • レイトレーシング解析を用いた26GHz帯電波のオフィス内伝播特性推定  [Not invited]
    山岸誠知, 日景隆, 山本学, 野島俊雄
    電気・情報関係学会北海道支部連合大会講演論文集(CD-ROM)  2017/10
  • 3D‐FEMシミュレーションを用いたEV充電WPT機器による植込み型医療器EMI評価法の基礎検討  [Not invited]
    佐藤尚樹, 日景隆, 山本学, 野島俊雄
    電気・情報関係学会北海道支部連合大会講演論文集(CD-ROM)  2017/10
  • 2GHz帯携帯無線端末使用時における頭部植込み型医療機周辺の局所SAR分布に関する偏波依存性  [Not invited]
    進藤和輝, 松田映美, 日景隆, 山本学, 野島俊雄
    電気・情報関係学会北海道支部連合大会講演論文集(CD-ROM)  2017/10
  • 近傍ばく露における埋め込み金属プレートによるSAR上昇の実験的評価  [Not invited]
    松田映美, 日景隆, 山本学, 野島俊雄, 長岡智明, 渡邊聡一
    電気・情報関係学会北海道支部連合大会講演論文集(CD-ROM)  2017/10
  • EAS機器による植込み型医療機器EMIの実験的評価法  [Not invited]
    近藤研, 日景隆, 野島俊雄
    電気・情報関係学会北海道支部連合大会講演論文集(CD-ROM)  2017/10
  • 進藤 和輝, 松田 映美, 日景 隆, 野島 俊雄
    電子情報通信学会技術研究報告 = IEICE technical report : 信学技報  2017/10
  • Numerical Estimation on Local SAR Enhancement in Considering Combined Exposures to Cellular Radio and Implanted Visual Prosthesis Featuring Wireless Power Transfer in Human Head  [Not invited]
    進藤和輝, 松田映美, 日景隆, 野島俊雄
    電子情報通信学会技術研究報告  2017/10
  • Active implantable medical device EMI estimation for EV-charging WPT system based on 3D full-wave analysis  [Not invited]
    Hikage Takashi, Yamagishi Masakazu, Shindo Kazuki, Nojima Toshio
    IEEE Conference Proceedings  2017/07 
    ? 2017 IEEE. A numerical assessment methodology of active implantable pacemaker EMI triggered by wireless power transfer system for electric vehicle charging is presented. A numerical model that consists of electric vehicle wireless power transfer system and a human phantom is developed and used in the simulation. The interference voltages induced at the implantable pacemaker model are obtained using three dimensional full-wave numerical simulations based upon the finite element method. We assume realistic exposure scenarios, when the orientation and location of the human are varied, in order to develop conservative estimates of the interference voltage.
  • Aircraft electromagnetic field estimation for wireless avionics intra-communication band using large-scale FDTD analysis - Field estimation of A320 class passenger aircraft at 4 GHz band  [Not invited]
    Futatsumori Shunichi, Morioka Kazuyuki, Kohmura Akiko, Yonemoto Naruto, Hikage Takashi, Yahagi Kanji, Shirafune Masami, Yamamoto Manabu, Nojima Toshio, Narahashi Shoichi
    IEEE Conference Proceedings  2017/05 
    ? 2017 ACES. Electromagnetic compatibly (EMC) is required to be investigated for newly introduced on-board Wireless Avionics Intra-Communication (WAIC) systems. In this paper, the feasibility of the detailed electromagnetic field (EMF) estimation method for the Airbus A320 class passenger aircraft at 4 GHz band is discussed. Firstly, the three-dimensional analysis model based on Airbus A320-200 aircraft is developed for the EMF estimation using the large-scale finite-difference time-domain (FDTD) method. Then, the material constants and the FDTD analysis parameters are discussed. Finally, the analyzed EMF characteristics confirm the effectiveness of the EMC investigation at WAIC band using the numerical analysis.
  • 日景 隆, 野島 俊雄
    電子情報通信学会技術研究報告 = IEICE technical report : 信学技報  2017/04
  • 日景 隆, 野島 俊雄
    電子情報通信学会技術研究報告 = IEICE technical report : 信学技報  2017/04
  • Statistical analysis method of radio propagation path loss for gas-smart meters in a built-up area based on large-scale FDTD simulation  [Not invited]
    Shirafune Masami, Hikage Takashi, Shindo Kazuki, Narahashi Shoichi, Nojima Toshio, Tsuchiya Sota, Kawata Takuya
    IEEE Conference Proceedings  2017/04 
    ? 2017 IEEE. This paper presents a large-scale Finite-Difference Time-Domain (FDTD) simulation as a prediction method for radio propagation characteristics for multi-hop communication of gas-smart meters in a built-up area. The frequency bands used in the simulations is 920 MHz-bands. By using the FDTD method to obtain precise and comprehensive results in multi-reflective environment, wave propagation from the gas-smart meters are observed and path loss characteristics are estimated statistically. Obtained larger path loss for the gas-smart meter in the built-up area compared with other propagation model, such as cellular communication, was more noticeable, and it is important for these effects need to be considered in the wireless link planning.
  • Active implantable medical device EMI assessment for wireless power transfer  [Not invited]
    日景隆, 野島俊雄
    電子情報通信学会技術研究報告  2017/04
  • 山岸 誠知, 日景 隆, 猪又 稔, 佐々木 元晴, 中村 光貴, 鷹取 泰司
    電子情報通信学会技術研究報告 = IEICE technical report : 信学技報  2017/04
  • FEM simulation of induced interference voltage at implantable cardiac pacemaker due to wireless power transfer in HF-band  [Not invited]
    Naoki Tanaka, Takashi Hikage, Juan C?rcoles, Toshio Nojima
    ISAP 2016 - International Symposium on Antennas and Propagation  2017/01 
    ? 2016 IEICE. A novel numerical Wireless Power Transfer (WPT)/Active Implantable Medical Device-EMI estimation methodology based upon finite element method analysis is presented. This assessment methodology can be applied to both Mobile/Portable-WPT system and electric-vehicle-WPT system. Here, an example for HF-band magnetic resonance type WPT is introduced. Simulated example includes different exposure scenarios in order to estimate the maximum interference voltage.
  • Large-scale FDTD analysis of 4.4 GHz-band propagation characteristics in aircraft cabin  [Not invited]
    Kanji Yahagi, Masami Shirafune, Takashi Hikage, Manabu Yamamoto, Toshio Nojima, Shoichi Narahashi, Syunichi Futatsumori, Akiko Kohmura, Naruto Yonemoto
    ISAP 2016 - International Symposium on Antennas and Propagation  2017/01 
    ? 2016 IEICE. Electromagnetic field (EMF) distributions generated by a 4.4 GHz-band wireless transmitter used in Wireless Avionics Intra Communications (WAIC) technology inside an aircraft cabin are analyzed and fundamental propagation characteristics are discussed from the analysis results. This paper uses FDTD method and a large-scale parallel computing technique to achieve calculation of whole aircraft (Airbus A320-200 model) including wings.
  • Aircraft Electromagnetic Field Estimation for Wireless Avionics Intra-Communication Band Using Large-Scale FDTD Analysis  [Not invited]
    2017 INTERNATIONAL APPLIED COMPUTATIONAL ELECTROMAGNETICS SOCIETY SYMPOSIUM - ITALY (ACES)  2017
  • 矢萩幹人, 日景隆, 山本学, 野島俊雄, 二ッ森俊一, 河村暁子, 米本成人
    電気・情報関係学会北海道支部連合大会講演論文集(CD-ROM)  2016/11
  • 橘友和, 日景隆, 野島俊雄
    電気・情報関係学会北海道支部連合大会講演論文集(CD-ROM)  2016/11
  • 白船雅巳, 日景隆, 山本学, 野島俊雄, 二ッ森俊一, 河村暁子, 米本成人
    電気・情報関係学会北海道支部連合大会講演論文集(CD-ROM)  2016/11
  • 田中尚樹, 日景隆, 山本学, 野島俊雄, 長岡智明, 渡邊聡一
    電気・情報関係学会北海道支部連合大会講演論文集(CD-ROM)  2016/11
  • 佐藤尚樹, 日景隆, 山本学, 野島俊雄
    電気・情報関係学会北海道支部連合大会講演論文集(CD-ROM)  2016/11
  • 進藤和輝, 日景隆, 山本学, 野島俊雄
    電気・情報関係学会北海道支部連合大会講演論文集(CD-ROM)  2016/11
  • 田中 尚樹, 日景 隆, 野島 俊雄, 井山 隆弘, 大西 輝夫
    電子情報通信学会技術研究報告 = IEICE technical report : 信学技報  2016/09
  • 田中尚樹, 日景隆, 野島俊雄, 井山隆弘, 大西輝夫
    電子情報通信学会技術研究報告  2016/09
  • 田中尚樹, 日景隆, 野島俊雄, 長岡智明, 渡邊聡一
    電子情報通信学会大会講演論文集(CD-ROM)  2016/09
  • 矢萩幹人, 白船雅巳, 日景隆, 山本学, 野島俊雄, 二ッ森俊一, 河村暁子, 米本成人
    電子情報通信学会大会講演論文集(CD-ROM)  2016/09
  • Identification and functional analysis of SVP ortholog in herbaceous perennial plant Gentiana triflora: Implication for its multifunctional roles  [Not invited]
    Yamagishi Noriko, Kume Kohei, Hikage Takashi, Hikage Takashi, Takahashi Yui, Bidadi Haniyeh, Wakameda Keisuke, Saitoh Yasushi, Saitoh Yasushi, Yoshikawa Nobuyuki, Tsutsumi Ken-ichi, Tsutsumi Ken-ichi
    Plant Science  2016/07
  • Effect of Passengers' Absorption onto Multi-path Suppression for Wireless LAN Propagation Analysis in High-Speed Train Cars based on FDTD Method  [Not invited]
    白船 雅巳, 日景 隆, 山本 学, 野島 俊雄, 猪又 稔, 佐々木 元晴, 山田 渉, 鬼沢 武
    電子情報通信学会技術研究報告 = IEICE technical report : 信学技報  2016/05
  • 白船雅巳, 日景隆, 山本学, 野島俊雄, 猪又稔, 佐々木元晴, 山田渉, 鬼沢武
    電子情報通信学会技術研究報告  2016/05
  • Masami Shirafune, Takashi Hikage, Manabu Yamamoto, Toshio Nojima, Minoru Inomata, Motoharu Sasaki, Wataru Yamada, Takeshi Onizawa
    2015 International Symposium on Antennas and Propagation, ISAP 2015  2016/04 
    © 2015 The Institute of Electronics, Information and Comm.The aim of this study is to develop an accurate and reliable method of estimating field distributions in train cars so as to advance radio link design of wireless LANs operated inside the cars. This paper describes effects of absorption and shielding caused by a large number of passengers on propagation characteristics of RF leakage from wireless access point operating in a bullet train. Field distributions created by a 2.4 GHz-band wireless transmitter inside cars, when oncoming train cars are passing through a double track railway tunnel, are analyzed and propagation characteristics are determined from the analysis results.
  • Allelic variants of the esterase gene W14/15 differentially regulate overwinter survival in perennial gentian (Gentiana L.)  [Not invited]
    HIKAGE Takashi, HIKAGE Takashi, YAMAGISHI Noriko, TAKAHASHI Yui, SAITOH Yasushi, YOSHIKAWA Nobuyuki, TSUTSUMI Ken‐ichi
    Mol Genet Genomics  2016/04
  • B-4-7 Measurement of Interference Voltage in Cellular Band Using an Electro-Optic Converter for Active Implantable Medical Device EMI assessment  [Not invited]
    TANAKA Naoki, HIKAGE Takashi, NOJIMA Toshio, IYAMA Takahiro, ONISHI Teruo
    Proceedings of the IEICE General Conference  2016/03
  • B-1-39 A Large-Scale Numerical Analysis of In-car Propagation Characteristics and RF Leakage to Oncoming Car of Wireless LAN in a Train Considering Loss due to Passengers' RF absorption  [Not invited]
    SHIRAFUNE Masami, HIKAGE Takashi, YAMAMOTO Manabu, NOJIMA Toshio, INOMATA Minoru, SASAKI Motoharu, YAMADA Wataru, ONIZAWA Takeshi
    Proceedings of the IEICE General Conference  2016/03
  • E/O変換器を用いた携帯電話周波数帯電波ばく露における植込み型医療機器EMI評価のための干渉誘起電圧測定  [Not invited]
    田中尚樹, 日景隆, 野島俊雄, 井山隆弘, 大西輝夫
    電子情報通信学会大会講演論文集(CD-ROM)  2016/03
  • 白船雅巳, 日景隆, 山本学, 野島俊雄, 猪又稔, 佐々木元晴, 山田渉, 鬼沢武
    電子情報通信学会大会講演論文集(CD-ROM)  2016/03
  • Estimation of Induced Interference Voltage at Implantable Cardiac Pacemaker Due to LF-band Wireless Power Transfer Coils  [Not invited]
    田中 尚樹, 日景 隆, 野島 俊雄
    電子情報通信学会技術研究報告 = IEICE technical report : 信学技報  2016/02
  • Estimation of Induced Interference Voltage at Implantable Cardiac Pacemaker Due to LF-band Wireless Power Transfer Coils  [Not invited]
    田中尚樹, 日景隆, 野島俊雄
    電子情報通信学会技術研究報告  2016/02
  • Numerical Estimation of Local SAR Enhancement Due to Cellular Radio Usage for Implantable Visual Prosthesis Featuring Wireless Power Transfer Coil in Human Head  [Not invited]
    進藤 和輝, 日景 隆, 野島 俊雄
    電子情報通信学会技術研究報告 = IEICE technical report : 信学技報  2016/01
  • FEM Simulation of Induced Interference Voltage at Implantable Cardiac Pacemaker Due to Wireless Power Transfer in HF-band  [Not invited]
    2016 INTERNATIONAL SYMPOSIUM ON ANTENNAS AND PROPAGATION (ISAP)  2016
  • Experimental estimation of SAR enhancement due to two parallel implanted metal plates using a head phantom and thermograph  [Not invited]
    Takashi Hikage, Naoki Tanaka, Toshio Nojima, Tomoaki Nagaoka, Soichi Watanabe
    MOBIHEALTH 2015 - 5th EAI International Conference on Wireless Mobile Communication and Healthcare - Transforming Healthcare through Innovations in Mobile and Wireless Technologies  2015/12 
    Copyright ? 2015 ICST. The main objective of this study is to assess whether two parallel metal plates implanted in the head region could be expected to cause SAR enhancements under UHF near-field exposure. In this paper, we achieve precise temperature distribution measurements for a physical head phantom implanted with two metallic plates using thermograph. The phantom was newly manufactured using silicone rubber and carbon material. In the measured distributions, temperature increase due to the metallic plates was clearly observed in the gap of two metal plates region. Obtained measurement data can be used for validation study for further SAR estimations using numerical analysis.
  • Estimation of RF leakage to oncoming train cars from wireless access point operating in bullet train passing through a tunnel  [Not invited]
    Masami Shirafune, Takashi Hikage, Manabu Yamamoto, Toshio Nojima, Minoru Inomata, Motoharu Sasaki, Wataru Yamada, Takeshi Onizawa
    2015 International Symposium on Antennas and Propagation, ISAP 2015  2015/11 
    ? 2015 The Institute of Electronics, Information and Comm.The aim of this study is to develop an accurate and reliable method of estimating field distributions in train cars so as to advance radio link design of wireless LANs operated inside the cars. This paper describes effects of absorption and shielding caused by a large number of passengers on propagation characteristics of RF leakage from wireless access point operating in a bullet train. Field distributions created by a 2.4 GHz-band wireless transmitter inside cars, when oncoming train cars are passing through a double track railway tunnel, are analyzed and propagation characteristics are determined from the analysis results.
  • Numerical Estimation of 4.4GHz-band Propagation Characteristics in Aircraft Cabin Using Large-Scale FDTD analysis  [Not invited]
    矢萩 幹人, 白船 雅巳, 日景 隆
    電子情報通信学会技術研究報告 = IEICE technical report : 信学技報  2015/11
  • Estimation of Induced Interference Voltage at Implantable Cardiac Pacemaker Due to HF-band Wireless Power Transfer Coils  [Not invited]
    田中 尚樹, 日景 隆, 野島 俊雄
    電子情報通信学会技術研究報告 = IEICE technical report : 信学技報  2015/11
  • 閉空間における生体電磁環境の安全性評価―電磁界解析に基づくエレベータ内ペースメーカEMI推定―  [Not invited]
    HIKAGE TAKASHI, NOJIMA TOSHIO
    電子情報通信学会大会講演論文集(CD-ROM)  2015/08
  • 下顎骨骨折治療用埋め込み金属プレートによるSAR上昇の実験的推定  [Not invited]
    TANAKA NAOKI, HIKAGE TAKASHI, NOJIMA TOSHIO, NAGAOKA TOMOAKI, WATANABE SOICHI
    電子情報通信学会大会講演論文集(CD-ROM)  2015/08
  • B-20-3 Experimental Estimation for SAR Enhancement Due to Implanted metal Plates for Mandibular fracture  [Not invited]
    TANAKA Naoki, HIKAGE Takashi, NOJIMA Toshio, NAGAOKA Tomoaki, WATANABE Soichi
    Proceedings of the Society Conference of IEICE  2015/08
  • BCS-1-1 An assessment for biological RF exposure safety in metallic enclosed environments : Numerical Estimation of EMI Impact by Mobile Radio on Implantable Cardiac Pacemakers in Elevator  [Not invited]
    HIKAGE Takashi, NOJIMA Toshio
    Proceedings of the Society Conference of IEICE  2015/08
  • Assessment of Electromagnetic Interference Due to Electric Vehicle Wireless Power Transfer System on Active Implantable Medical Devices  [Not invited]
    日景 隆, 白船 雅巳, 野島 俊雄
    電子情報通信学会技術研究報告 = IEICE technical report : 信学技報  2015/06
  • 電気光変換器を用いた植込み型医療機器EMI評価のための干渉誘起電圧測定系  [Not invited]
    HIKAGE TAKASHI, ONO TAISUKE, NOJIMA TOSHIO, IYAMA TAKAHIRO, HIGASHIYAMA JUNJI, ONISHI TERUO
    電子情報通信学会大会講演論文集(CD-ROM)  2015/02
  • B-20-7 Experimental Estimation for SAR Enhancement Due to Implanted metal Plates Using Thermographic Method  [Not invited]
    ONO Taisuke, HIKAGE Takashi, NOJIMA Toshio, NAGAOKA Tomoaki, WATANABE Soichi
    Proceedings of the IEICE General Conference  2015/02
  • B-4-22 Measurement Set-up Using an Electro-Optic Converter for Interference Voltage of Active Implantable Medical Devices EMI Assessment  [Not invited]
    HIKAGE Takashi, ONO Taisuke, NOJIMA Toshio, IYAMA Takahiro, HIGASHIYAMA Junji, ONISHI Teruo
    Proceedings of the IEICE General Conference  2015/02
  • B-1-162 Estimation of RF Leakage to Oncoming Train Cars from Wireless Access Point Operating in High-Speed Train Passing Through a Tunnel  [Not invited]
    SHIRAFUNE Masami, HIKAGE Takashi, NOJIMA Toshio, SASAKI Motoharu, YAMADA Wataru, SUGIYAMA Takatoshi
    Proceedings of the IEICE General Conference  2015/02
  • Masami Shirafune, Takashi Hikage, Toshio Nojima, Motoharu Sasaki, Wataru Yamada, Takatoshi Sugiyama
    ISAP 2014 - 2014 International Symposium on Antennas and Propagation, Conference Proceedings  2015/01  Institute of Electrical and Electronics Engineers Inc.
     
    The aim of this study is to develop an accurate and reliable method to estimate field distributions in train cars so as to advance radio link design of wireless LANs operating inside the cars. This paper describes effects of reflected waves due to tunnel wall and/or train passing on opposite track on propagation characteristics inside the high-speed train cars in a typical railway tunnel. Field distributions created by a 2.4 GHzband wireless transmitter inside cars are analyzed and exemplary propagation characteristics are determined statistically from large-scale numerical analysis results.
  • Propagation characteristic estimations of 2 GHz inter-car wireless links in high-speed train cars in a railway tunnel  [Not invited]
    Masami Shirafune, Takashi Hikage, Toshio Nojima, Motoharu Sasaki, Wataru Yamada, Takatoshi Sugiyama
    ISAP 2014 - 2014 International Symposium on Antennas and Propagation, Conference Proceedings  2015/01 
    ? 2014 Institute of Antenna Engineers of Taiwan.The aim of this study is to develop an accurate and reliable method to estimate field distributions in train cars so as to advance radio link design of wireless LANs operating inside the cars. This paper describes effects of reflected waves due to tunnel wall and/or train passing on opposite track on propagation characteristics inside the high-speed train cars in a typical railway tunnel. Field distributions created by a 2.4 GHzband wireless transmitter inside cars are analyzed and exemplary propagation characteristics are determined statistically from large-scale numerical analysis results.
  • Taisuke Ono, Takashi Hikage, Toshio Nojima, Tomoaki Nagaoka, Soichi Watanabe
    IEEE iWEM 2014 - IEEE International Workshop on Electromagnetics: Applications and Student Innovation Competition  2014/11  Institute of Electrical and Electronics Engineers Inc.
     
    RF exposure guidelines recognize that an increase in local SAR due to metallic implants is possible, depending upon the size and shape of the implant and the position. This study describes the local SAR calculations for an anatomical human with metallic osteosynthesis plates embedded in the mandibular zone exposed to 2GHz RF fields FDTD analysis is applied. The main objective is to assess whether combination of two metallic plates aligned in parallel in the head region could be expected to cause SAR enhancements under near-field exposure condition at 2 GHz.
  • Takashi Hikage, Masami Shirafune, Toshio Nojima, Shunichi Futatsumori, Akiko Kohmura, Naruto Yonemoto
    IEEE iWEM 2014 - IEEE International Workshop on Electromagnetics: Applications and Student Innovation Competition  2014/11  Institute of Electrical and Electronics Engineers Inc.
     
    Electromagnetic field distributions established in a commercial aircraft, Boeing 777 class large passenger aircraft, due to a personal electric device are evaluated. We use FDTD technique and a large-scale parallel computing technique to precisely estimate the EMF distributions. In order to evaluate EMF characteristics including the whole structure of the aircraft such as the wings and engines, the dimensions of the aircraft model used in the analysis are as accurate as possible. Based on field distribution analyses, interference path loss for aircraft communication and navigation receivers from a 2 GHz band wireless transmitter inside the cabin are obtained statistically.
  • 強制照射・サーモグラフィ法を用いた埋め込み金属プレートによるSAR上昇の実験的推定  [Not invited]
    小野泰伴, 日景隆, 野島俊雄, 長岡智明, 渡邊聡一
    電気・情報関係学会北海道支部連合大会講演論文集(CD-ROM)  2014/10
  • HF帯ワイヤレス電力伝送コイル近傍における植込み型心臓ペースメーカ干渉誘起電圧のFEM解析―心房・心室リードの比較―  [Not invited]
    政木遥, 小野泰伴, 日景隆, 野島俊雄
    電気・情報関係学会北海道支部連合大会講演論文集(CD-ROM)  2014/10
  • 電力伝送コイルの位置ずれを考慮した人工視覚システム埋め込み人体の局所SAR推定  [Not invited]
    日景隆, 小野泰伴, 野島俊雄, 米澤栄二, 大澤孝治
    電気・情報関係学会北海道支部連合大会講演論文集(CD-ROM)  2014/10
  • FDTD解析を用いた航空機客室‐機上アンテナ間の経路損失評価  [Not invited]
    白船雅巳, 日景隆, 野島俊雄, 二ッ森俊一, 河村暁子, 米本成人
    電気・情報関係学会北海道支部連合大会講演論文集(CD-ROM)  2014/10
  • Shunichi Futatsumori, Kazuyuki Morioka, Akiko Kohmura, Naruto Yonemoto, Masami Shirafune, Takashi Hikage, Toshio Nojima
    IEEE International Symposium on Electromagnetic Compatibility  2014/10  Institute of Electrical and Electronics Engineers Inc.
     
    Effects on electromagnetic field (EMF) characteristics inside aircraft due to internal structures, such as phenol internal walls are experimentally investigated using a reverberation chamber. This is aiming to improve the accuracy of the numerical analysis method for the electromagnetic compatibility estimation of the Boeing 777 class large aircraft based on finite-difference time-domain (FDTD) technique. Firstly, the FDTD analysis results of B777-200ER aircraft are compared with that of measured results. The dependencies of material constants of the aircraft model are briefly discussed. Secondly, the EMF loss due to the phenol walls is measured quantitatively using the reverberation chamber. The performance of the chamber is evaluated by the statistical analysis. The field uniformity evaluated by the measured electric field (E-field) strength is less than 3 dB between 500 MHz and 6 GHz. Next, the cumulative distribution function of the measured E-field strength is in good agreement with the theoretical Rayleigh distribution. Finally, the measured quality factor, which is reduced by 20 % at 2 GHz and 25 % at 5 GHz, confirms the loss of EMF due to the phenol walls.
  • Numerical Analysis of Local SAR of Human Implanted with Visual Prosthesis Featuring Wireless Power Transfer Coil in Head  [Not invited]
    日景 隆, 小野 泰伴, 野島 俊雄
    電子情報通信学会技術研究報告 = IEICE technical report : 信学技報  2014/10
  • An Estimation on Induced Voltage at Implantable Cardiac Pacemaker due to Magnetic Resonant Wireless Power Transfer Coils Using Finite Element Method  [Not invited]
    小野 泰伴, 日景 隆, 野島 俊雄
    電子情報通信学会技術研究報告 = IEICE technical report : 信学技報  2014/10
  • Numerical Analysis of Local SAR of Human Implanted with Visual Prosthesis Featuring Wireless Power Transfer Coil in Head  [Not invited]
    HIKAGE TAKASHI, ONO TAISUKE, NOJIMA TOSHIO, YONEZAWA EIJI, OSAWA KOJI
    電子情報通信学会技術研究報告  2014/10 
    This study describes local specific absorption rate (SAR) calculations for anatomical human implanted with visual prosthesis featuring wireless power transfer (WPT) coil in head. A numerical estimation model that consists of a human head and an internally implanted component of the visual prosthesis including the WPT coil is constructed. By using Finite-difference time-domain (FDTD) analysis, electromagnetic fields distribution inside the human head is calculated and peak values of 10g-averaged SAR are evaluated.
  • An Estimation on Induced Voltage at Implantable Cardiac Pacemaker due to Magnetic Resonant Wireless Power Transfer Coils Using Finite Element Method  [Not invited]
    ONO TAISUKE, HIKAGE TAKASHI, NOJIMA TOSHIO
    電子情報通信学会技術研究報告  2014/10 
    A numerical assessment methodology of active implantable medical device (implantable cardiac pacemaker / implantable cardioverter defibrillator) EMI triggered by magnetic resonance wireless power transmission (WPT) antennas is discussed. A numerical estimation model that consists of magnetic resonant coils and a human torso phantom including a pacemaker model is constructed. By using Finite element method (FEM), interference voltage induced at the connector of the pacemaker inside the human phantom is calculated. We consider, as an example, magnetic resonance WPT antennas operating on HF frequency band in this paper.
  • トンネル通過時の高速鉄道車両内2GHz帯電波の伝搬推定  [Not invited]
    白船雅巳, 日景隆, 野島俊雄, 佐々木元晴, 山田渉, 杉山隆利
    電子情報通信学会大会講演論文集(CD-ROM)  2014/03
  • 航空機内構造物が内部電磁界伝搬特性に及ぼす影響―フェノール内壁を付加した電波反射箱の構造体Q値測定評価―  [Not invited]
    二ッ森俊一, 森岡和行, 河村暁子, 米本成人, 白船雅巳, 日景隆, 野島俊雄
    電子情報通信学会大会講演論文集(CD-ROM)  2014/03
  • 非接触充電器による植込み型医療機器EMIのin vitro試験  [Not invited]
    日景隆, 白船雅巳, 野島俊雄, 藤本裕, 岩井洋
    電子情報通信学会大会講演論文集(CD-ROM)  2014/03
  • 金属プレート埋め込みファントムの2GHz帯SARおよび温度上昇推定  [Not invited]
    小野泰伴, 日景隆, 野島俊雄, 長岡智明, 渡邊聡一
    電子情報通信学会大会講演論文集(CD-ROM)  2014/03
  • 非接触電力伝送コイル付人工視覚システム埋め込み人体の局所SAR推定  [Not invited]
    日景隆, 小野泰伴, 野島俊雄, 米澤栄二, 大澤孝治
    電子情報通信学会大会講演論文集(CD-ROM)  2014/03
  • BI-4-4 In vitro Assessments of Active Implantable Medical Devices EMI from Radio Wave Emitted by Wireless Power Transfer Devices  [Not invited]
    HIKAGE Takashi, SHIRAFUNE Masami, NOJIMA Toshio, FUJIMOTO Hiroshi, IWAI Hiroshi
    Proceedings of the IEICE General Conference  2014/03
  • B-4-40 SAR & Temperature Elevation Estimations for a Phantom Model Implanted with Metal Plates Exposed to 2GHz Radio-Waves  [Not invited]
    ONO Taisuke, HIKAGE Takashi, NOJIMA Toshio, NAGAOKA Tomoaki, WATANABE Soichi
    Proceedings of the IEICE General Conference  2014/03
  • B-4-34 Numerical Analysis of Local SAR of Human Model Implanted with Visual Prosthesis Featuring Wireless Power Transfer Coil in Head  [Not invited]
    HIKAGE Takashi, ONO Taisuke, NOJIMA Toshio, YONEZAWA Eiji, OSAWA Kouji
    Proceedings of the IEICE General Conference  2014/03
  • B-4-4 Effects on Electromagnetic Field Characteristics Inside Aircrafts Due to Internal Structures : Measurement of Quality Factor of Cubic Reverberation Chamber With Phenol Internal Walls  [Not invited]
    FUTATSUMORI Shunichi, MORIOKA Kazuyuki, KOHMURA Akiko, YONEMOTO Naruto, SHIRAFUNE Masami, HIKAGE Takashi, NOJIMA Toshio
    Proceedings of the IEICE General Conference  2014/03
  • B-1-12 Propagation Characteristic Estimations of 2 GHz Intra-Car Wireless Links in High-Speed Train Cars in Railway Tunnel  [Not invited]
    SHIRAFUNE Masami, HIKAGE Takashi, NOJIMA Toshio, SASAKI Motoharu, YAMADA Wataru, SUGIYAMA Takatoshi
    Proceedings of the IEICE General Conference  2014/03
  • Propagation Characteristic Estimations of 2.4 GHz Inter-Car Wireless Links in High-Speed Train Cars in Railway Tunnel  [Not invited]
    日景 隆, 白船 雅巳, 野島 俊雄
    電子情報通信学会技術研究報告 = IEICE technical report : 信学技報  2014/02
  • Propagation Characteristic Estimations of 2.4 GHz Inter-Car Wireless Links in High-Speed Train Cars in Railway Tunnel  [Not invited]
    HIKAGE TAKASHI, SHIRAFUNE MASAMI, NOJIMA TOSHIO, SASAKI MOTOHARU, YAMADA WATARU, SUGIYAMA TAKATOSHI
    電子情報通信学会技術研究報告  2014/01 
    The aim of this study is to develop an accurate and reliable method of estimating field (EMF) distributions in train cars so as to advance radio link design of wireless LANs operated inside the cars. Previously, the authors investigated propagation characteristics for wireless LAN inside a typical commuter train and high-speed train using FDTD technique and a large-scale parallel computing technique. This paper describes propagation characteristic of Inter-Car wireless links in high-speed train in railway tunnel. EMF distributions created by a 2.4GHz wireless transmitter inside cars are analyzed and propagation characteristics are determined from the analysis results.
  • Electromagnetic field propagation characteristics of boeing 777 class large passenger aircraft-Numerical estimation and measurement results at 2 Ghz band  [Not invited]
    Shunichi Futatsumori, Kazuyuki Morioka, Akiko Kohmura, Narutoc Yonemoto, Masami Shirafune, Takashi Hikage, Toshio Nojima
    Annual Review of Progress in Applied Computational Electromagnetics  2014/01 
    Electromagnetic field (EMF) propagation characteristics including the whole body of a Boeing 777 class large passenger aircraft is analyzed by a parallel computing finite-difference time-domain technique. The analyzed EMF distributions in the aircraft cabin are in good agreement with measured distributions. The developed EMF analysis method can be applied for electromagnetic compatibility evaluations of aircrafts.
  • Evaluation of effects on electromagnetic field characteristics inside aircraft due to phenol internal structures using a reverberation chamber  [Not invited]
    Shunichi Futatsumori, Kazuyuki Morioka, Akiko Kohmura, Naruto Yonemoto, Masami Shirafune, Takashi Hikage, Toshio Nojima
    IEEE International Symposium on Electromagnetic Compatibility  2014/01 
    ? 2014 IEEE.Effects on electromagnetic field (EMF) characteristics inside aircraft due to internal structures, such as phenol internal walls are experimentally investigated using a reverberation chamber. This is aiming to improve the accuracy of the numerical analysis method for the electromagnetic compatibility estimation of the Boeing 777 class large aircraft based on finite-difference time-domain (FDTD) technique. Firstly, the FDTD analysis results of B777-200ER aircraft are compared with that of measured results. The dependencies of material constants of the aircraft model are briefly discussed. Secondly, the EMF loss due to the phenol walls is measured quantitatively using the reverberation chamber. The performance of the chamber is evaluated by the statistical analysis. The field uniformity evaluated by the measured electric field (E-field) strength is less than 3 dB between 500 MHz and 6 GHz. Next, the cumulative distribution function of the measured E-field strength is in good agreement with the theoretical Rayleigh distribution. Finally, the measured quality factor, which is reduced by 20 % at 2 GHz and 25 % at 5 GHz, confirms the loss of EMF due to the phenol walls.
  • Estimation of the electromagnetic fields excited by a cellular phone in a typical aircraft cabin  [Not invited]
    Masami Shirafune, Takashi Hikage, Toshio Nojima, Shunichi Futatsumori, Akiko Kohmura, Naruto Yonemoto
    IEEE International Symposium on Electromagnetic Compatibility  2014/01 
    ? 2014 The Institute of Electronics, Information and Communication Engineer.The aim of this study is to develop accurate and reliable estimation method of EMF distributions in aircraft that can contribute to numerical EMI assessment technique. Electromagnetic field distributions created by a cellular radio inside a cabin of aircraft are analyzed and propagation characteristics are discussed from the analysis results. We use FDTD technique and a large-scale parallel computing technique to precisely estimate the field distributions inside cabin of Boeing 777-200 aircraft model.
  • Numerical estimations of propagation characteristics and interference path loss due to personal electric device in a commercial aircraft cabin  [Not invited]
    Takashi Hikage, Masami Shirafune, Toshio Nojima, Shunichi Futatsumori, Akiko Kohmura, Naruto Yonemoto
    IEEE iWEM 2014 - IEEE International Workshop on Electromagnetics: Applications and Student Innovation Competition  2014/01 
    ? 2014 IEEE.Electromagnetic field distributions established in a commercial aircraft, Boeing 777 class large passenger aircraft, due to a personal electric device are evaluated. We use FDTD technique and a large-scale parallel computing technique to precisely estimate the EMF distributions. In order to evaluate EMF characteristics including the whole structure of the aircraft such as the wings and engines, the dimensions of the aircraft model used in the analysis are as accurate as possible. Based on field distribution analyses, interference path loss for aircraft communication and navigation receivers from a 2 GHz band wireless transmitter inside the cabin are obtained statistically.
  • Local SAR in anatomical phantom implanted with metallic osteosynthesis plates in mandibular exposed to 2 GHz RF fields  [Not invited]
    Taisuke Ono, Takashi Hikage, Toshio Nojima, Tomoaki Nagaoka, Soichi Watanabe
    IEEE iWEM 2014 - IEEE International Workshop on Electromagnetics: Applications and Student Innovation Competition  2014/01 
    ? 2014 IEEE.RF exposure guidelines recognize that an increase in local SAR due to metallic implants is possible, depending upon the size and shape of the implant and the position. This study describes the local SAR calculations for an anatomical human with metallic osteosynthesis plates embedded in the mandibular zone exposed to 2GHz RF fields; FDTD analysis is applied. The main objective is to assess whether combination of two metallic plates aligned in parallel in the head region could be expected to cause SAR enhancements under near-field exposure condition at 2 GHz.
  • Implantable cardiac pacemaker EMI triggered by HF-band wireless power transfer coils  [Not invited]
    Takashi Hikage, Masami Shirafune, Toshio Nojima
    IEEE International Symposium on Electromagnetic Compatibility  2014/01 
    ? 2014 The Institute of Electronics, Information and Communication Engineer.We introduce a numerical assessment methodology to understand the EMI imposed by coupled-resonant type wireless power transfer systems on active implantable medical devices (implantable cardiac pacemaker / cardioverter defibrillator). A numerical estimation model that consists of resonant coils and a human torso phantom with a pacemaker model is constructed. Numerical simulation based on the finite element method yields the interference voltage induced at the connector of the pacemaker inside the torso phantom. Our example assumes magnetic resonant coupling coils operating in the frequency band of 10 MHz.
  • A new improved electrode for the human body model: Application for EMI assessment of Active Implant Medical Devices  [Not invited]
    Hiroshi Fujimoto, Takeshi Toyoshima, Takashi Hikage, Toshio Nojima
    IEEE International Symposium on Electromagnetic Compatibility  2014/01 
    ? 2014 The Institute of Electronics, Information and Communication Engineer.The newly developed electrode for human body model, which is used for evaluation of EMI to a cardiac Active Implant Medical Device (AIMD), is reported. The electrode consists of applying and monitoring of signal portion and reduces crosstalk and signal leakage in application of cardiac pacing and sensing. It is practical and sufficient means of simulating EMI effects to an AIMD.
  • Local SAR evaluation of anatomical human implanted with metallic osteosynthesis plates exposed to UHF radio waves  [Not invited]
    Takashi Hikage, Yoshifumi Kawamura, Toshio Nojima, Tomoaki Nagaoka, Soichi Watanabe
    IEEE International Symposium on Electromagnetic Compatibility  2013/12 
    RF exposure guidelines recognize that an increase in local SAR (specific absorption rate) due to metallic implants is possible, depending upon the size and shape of the implant and the position. In this study, the effect of implanting metallic osteosynthesis plates in the human head region is examined by using FDTD analysis. The main objective is to simulate whether combination of two metallic plates aligned in parallel in the head region could be expected to cause SAR enhancements. An anatomical phantom model is used in which osteosynthesis plates of mandibular fractures are implanted. In the numerical modeling of the osteosynthesis plates, topological morphing operation is used. The peak 10-g averaged SAR dependencies in the mandibular zone are quantitatively investigated with metal plates of various sizes and shapes under far- and near-field exposure conditions. ? 2013 EMC Europe Foundation.
  • 無線電力伝送コイル近傍界による植込み型医療機器EMIのFDTD解析  [Not invited]
    小野泰伴, 日景隆, 野島俊雄
    電気・情報関係学会北海道支部連合大会講演論文集(CD-ROM)  2013/10
  • 列車内無線LAN電波の車車間伝搬に及ぼす車両間ドアの遮蔽影響推定―ドア窓の寸法と損失の関係―  [Not invited]
    白船雅巳, 日景隆, 野島俊雄
    電気・情報関係学会北海道支部連合大会講演論文集(CD-ROM)  2013/10
  • 有限要素法を用いた磁界共振型ワイヤレス電力伝送コイル近傍における植込み型心臓ペースメーカ干渉誘起電圧の推定―単極・双極モードの比較―  [Not invited]
    鈴木琢馬, 日景隆, 野島俊雄
    電気・情報関係学会北海道支部連合大会講演論文集(CD-ROM)  2013/10
  • In vitro assessment of EMI from RFID interrogator on implantable cardiac pacemakers and implantable cardioverter defibrillators  [Not invited]
    Takashi Hikage, Masami Shirafune, Toshio Nojima, Hiroshi Fujimoto, Takeshi Toyoshima
    2013 International Symposium on Electromagnetic Theory, EMTS 2013 - Proceedings  2013/09 
    Electromagnetic interference (EMI) characteristics of implantable cardiac pacemakers and cardioverter defibrillators (ICDs) based on assessments of RFID interrogators are described in this paper. Examples of interrogators operating in various RF bands are tested to estimate EMI experienced by pacemakers and ICDs. The EMI test set-up and some experimental evaluation results for practical devices are shown. Observed characteristics of the EMI occurrence are discussed based upon the transmission radio wave specifications. ? 2013 IEICE.
  • Whole-body averaged SAR measurements using cylindrical-external field scanning for 2 GHz plane wave irradiation of human models  [Not invited]
    Takashi Hikage, Yoshifumi Kawamura, Toshio Nojima, Tomoaki Nagaoka, Soichi Watanabe
    2013 7th European Conference on Antennas and Propagation, EuCAP 2013  2013/08 
    This paper presents measured whole-body averaged specific absorption rate (WB-SAR) values for human phantom models under 2GHz far-field exposure. Using cylindrical-external field scanning, we develop an experimental WB-SAR measurement system for far-field exposure. A key characteristic is that it can be easily applied to human phantoms that have different postures or sizes, because it is not necessary to determine the electromagnetic components distributed inside the phantom. The postured human phantoms used in this paper were designed from enhanced high-resolution numerical human models and fabricated from 2/3 muscle-equivalent tissue material consisting of carbon materials embedded in silicone. The measurement WB-SAR values for male adult and child human phantom were, under the ICNIRP reference level exposure condition, comparable with the numerical calculation results that have been reported. ? 2013 EurAAP.
  • Evaluation of Propagation Characteristics for Wireless LAN on Aircraft Considering the Wings  [Not invited]
    SHIRAFUNE MASAMI, HIKAGE TAKASHI, NOJIMA TOSHIO, FUTATSUMORI SHUN'ICHI, KOMURA AKIKO, YONAMOTO NARUTO
    電気学会電磁界理論研究会資料  2013/07
  • Evaluation of Propagation Characteristics for Wireless LAN on Aircraft Considering the Wings  [Not invited]
    SHIRAFUNE Masami, HIKAGE Takashi, NOJIMA Toshio, FUTATSUMORI Shunichi, KOHMURA Akiko, YONEMOTO Naruto
    Technical report of IEICE. OPE  2013/07 
    Demand for wireless broadband access services in long-distance transportations, such as trains and aircrafts, continues to grow. Recently, some airlines have begun in-flight call and in-flight wireless LAN access service. The final goal of this study is to develop an accurate and reliable numerical estimation tool of electromagnetic fields distributions inside aircraft so as to advance radio link design of wireless terminals operated inside the cabin. The authors previously proposed an EMF estimation method for an aircraft based on FDTD analysis and parallel computing. The EMF distributions established in the cabin of a Boeing 777- 200ER model due to a cellular radio were evaluated. In that modeling, the wings of the aircraft were not modeled in the analysis due to the limit of computational memory capability. This paper evaluates the propagation characteristics in cabin of Boeing 777-200ER by using newly developed numerical model of the aircraft which has the wings. In order to make the correct modeling of structures with details feasible, non-uniform gridding technique is employed. EMF distributions created by a 2 GHz band wireless transmitter inside the cabin are analyzed and propagation loss characteristics are obtained.
  • Inheritance of resistance to brown leaf spot disease in gentians  [Not invited]
    NEKODUKA Syuuichi, HORAGUCHI Hiroaki, AKASAKA Shihio, CHIBA Ken‐ichi, HIKAGE Takashi, KAWAMURA Hiromi, NAKATSUKA Takashi, NISHIHARA Masahiro
    J Gen Plant Pathol  2013/05
  • B-1-51 Numerical Estimation of RF Leakage from Wireless Access Point Operating in High-Speed Train Car  [Not invited]
    SHIRAFUNE Masami, HIKAGE Takashi, NOJIMA Toshio, YAMADA Wataru, SUGIYAMA Takatoshi
    Proceedings of the IEICE General Conference  2013/03
  • B-4-11 Thermographic SAR Estimation in a Phantom Model lmplanted with Metal Plates Exposed to 2 GHz Radio-Waves  [Not invited]
    KAWAMURA Yoshifumi, HIKAGE Takashi, NOJIMA Toshio, NAGAOKA Tomoaki, WATANABE Soichi
    Proceedings of the IEICE General Conference  2013/03
  • In vitro Assessment of EMI from RFID Interrogator on Implantable Cardiac Pacemakers/cardioverter defibrillators  [Not invited]
    HIKAGE Takashi, KAWAMURA Yoshifumi, NOJIMA Toshio, FUJIMOTO Hiroshi, TOYOSHIMA Takeshi
    電気学会研究会資料. EMC, 電磁環境研究会  2013/03
  • FDTD Analysis of Shielding Effect of Connecting Doors for Wireless LAN Access Service in High-Speed Train Cars  [Not invited]
    日景 隆, 白船 雅巳, 野島 俊雄
    電子情報通信学会技術研究報告 : 信学技報  2013/01
  • FDTD Analysis of Shielding Effect of Connecting Doors for Wireless LAN Access Service in High-Speed Train Cars  [Not invited]
    HIKAGE Takashi, SHIRAFUNE Masami, OJIMA Toshio, YAMADA Wataru, KITA Naoki, SUGIYAMA Takatoshi
    IEICE technical report. Antennas and propagation  2013/01 
    The aim of this study is to develop an accurate and reliable method of estimating field (EMF) distributions in tram cars so as to advance radio link design of wireless LANs operated inside the cars. Previously, the authors investigated propagation characteristics for wireless LAN inside a typical commuter tram and high-speed tram using FDTD technique and a large-scale parallel computing technique. This paper describes shielding effects due to connecting doors on propagation characteristics inside the high-speed tram cars EMF distributions created by a 2.4GHz wireless transmitter inside cars are analyzed and propagation characteristics are determined from the analysis results. In order to estimate the shielding effect by the doors, we derive histograms of the electric field distributions throughout the whole interior of the cars.
  • Efficient haploid and doubled haploid production from unfertilized ovule culture of gentians (Gentiana spp.)  [Not invited]
    DOI Hisako, HOSHI Nobue, YAMADA Eri, YOKOI Shuji, NISHIHARA Masahiro, HIKAGE Takashi, TAKAHATA Yoshihito
    Breed Sci  2013
  • Large-scale FDTD analysis to obtain precise propagation characteristics of in-flight wireless access service  [Not invited]
    Takashi Hikage, Toshio Nojima, Shunichi Futatsumori, Akiko Kohmura, Naruto Yonemoto
    IEEE AFRICON Conference  2013/01 
    Electromagnetic field distributions created by a 2 GHz band wireless transmitter inside an aircraft cabin are analyzed and propagation characteristics are discussed from the analysis results. We use FDTD technique and a large-scale parallel computing technique to precisely estimate the field distributions inside cabin of a Boeing 777-200 aircraft model. In order to validate FDTD analysis results, the calculated electric field distribution is compared to actual field measurement in the aircraft cabin. Additionally, the absorption effect due to passengers can be considered. ? 2013 IEEE.
  • Numerical assessment method for implantable cardiac pacemaker EMI triggered by 10MHz-band wireless power transfer coils  [Not invited]
    Takuma Suzuki, Takashi Hikage, Toshio Nojima
    2013 IEEE MTT-S International Microwave Workshop Series on RF and Wireless Technologies for Biomedical and Healthcare Applications, IMWS-BIO 2013 - Proceedings  2013/01 
    A numerical assessment methodology to understand the EMI imposed by magnetic resonance type wireless power transfer systems on active implantable medical devices (implantable cardiac pacemaker/cardioverter defibrillator) is introduced. A numerical estimation model that consists of magnetic resonant coils and a human torso phantom with a pacemaker model is constructed. Numerical simulation based on the finite element method yields the interference voltage induced at the connector of the pacemaker inside the torso phantom. Our example assumes magnetic resonance coils operating in the frequency band of 10 MHz. ? 2013 IEEE.
  • Numerical assessment methodology for active implantable medical device EMI due to magnetic resonance wireless power transmission antenna  [Not invited]
    Takashi Hikage, Yoshifumi Kawamura, Toshio Nojima, Eugenia Cabot
    IEEE International Symposium on Electromagnetic Compatibility  2012/12 
    This paper introduces a numerical assessment methodology of the EMI triggered by magnetic resonance wireless power transmission antennas and imposed on active implantable medical devices such as implantable-cardiac pacemakers and cardioverter defibrillators. A numerical estimation model that consists of magnetic resonant coils and a human torso phantom is constructed. Interference voltage induced at the connector of the pacemaker inside the human phantom is calculated. We consider, as an example, magnetic resonance WPT antennas operating the frequency band of 10 MHz, with air-gap of less than 0.5 m. Finally, the calculated interference voltage is compared with the EMI characteristics obtained by in-vitro EMI experiments. ? 2012 IEEE.
  • EMI risk assessment of electromagnetic field from mobile phone in elevator cabin for implantable pacemaker  [Not invited]
    Junji Higashiyama, Yoshiaki Tarusawa, Takashi Hikage, Toshio Nojima
    IEEE International Symposium on Electromagnetic Compatibility  2012/12 
    The electromagnetic interference impact of a mobile phone to implantable medical device in an elevator cabin is discussed based on electric field distribution measurement data. To measure the field strength, a simulated elevator cabin is constructed according to industry standards, which conform to wheelchair use. The resultant measured field strength shows that there is no electric field strength that has the potential to yield electromagnetic interference between an implantable cardiac pacemaker and a mobile phone if the isolation distance recommended by the pacemaker user guidelines is maintained for the implanted cardiac pacemaker. ? 2012 IEEE.
  • Whole-body averaged SAR measurements of postured phantoms exposed to E-/H-polarized plane-wave using cylindrical field scanning  [Not invited]
    Yoshifumi Kawamura, Takashi Hikage, Toshio Nojima, Tomoaki Nagaoka, Soichi Watanabe
    IEEE Antennas and Propagation Society, AP-S International Symposium (Digest)  2012/12 
    The aim of this study is to achieve experimental estimation of whole-body averaged specific absorption rate (WB-SAR) of human models using the radiation-field scanning technique. The original relationship between the WB-SAR and the reference level of ICNIRP Guidelines [1] was obtained through the theoretical analyses using the simple geometrical or block structure. Recently, high resolution numerical simulations have become possible through the use of highspeed computers and high accuracy human phantoms based on magnetic resonance imaging [2], [3]. On the other hand, some experiments to investigate the same subject have been reported [4]. It is very important to obtain reliable measurement data that can contribute to the validation of recent precise computation-based estimations. ? 2012 IEICE.
  • Numerical estimations of the propagation characteristics of wireless links in high-speed train cars  [Not invited]
    Takashi Hikage, Masami Shirafune, Toshio Nojima, Wataru Yamada, Takatoshi Sugiyama
    IEEE Antennas and Propagation Society, AP-S International Symposium (Digest)  2012/12 
    Demand for wireless broadband access services in long-distance transportations continues to grow. Several railway companies have recently begun in-car wireless LAN services [1]. In order to advance the radio link design in support of such services, an accurate and reliable method for estimating the electromagnetic environment in actual situations is required. However, comprehensive on-site field measurements cost too much, and it is difficult to carry them out precisely. In addition, measurements must take account of the absorbing effects due to many passengers triggering the drawbacks of poor feasibility and repeatability. This study introduces an accurate and reliable method of estimating electromagnetic field (EMF) distributions in train cars so as to advance the radio link design of wireless LANs operated inside train cars. The authors previously proposed an EMF estimation method for a typical commuter train based on FDTD analysis and parallel computing [2]. This paper evaluates the propagation characteristics in a High-Speed Train Car (HSTC). Using newly developed numerical models of HSTC, which include many passengers, EMF distributions created by a 5.2 GHz wireless transmitter inside the HSTC are analyzed and propagation characteristics are evaluated. In order to estimate the effect of the absorption by the passengers' bodies, simplified histograms of the electric field distributions throughout the whole interior of the car are derived. ? 2012 IEICE.
  • Harmonic matching and reflecting amplifiers with 2nd and 3rd harmonic phase tuning  [Not invited]
    Ken Hiraga, Takashi Hikage, Manabu Yamamoto, Toshio Nojima
    IEEE Antennas and Propagation Society, AP-S International Symposium (Digest)  2012/12 
    Efficiency of power amplifiers has been a major issue in the field of wireless transmitters and microwave power transmitters. Accordingly, many techniques for high efficiency have been proposed [1][2]. The use of class-F amplifiers has been considered to be one of the most effective approaches at microwave or higher frequencies. The drain efficiency is 100% for ideal class-F operation with an infinite number of harmonics in operating waveforms [2]. Such operation is realized with complete load conditions [3]. ? 2012 IEICE.
  • Local SAR Estimation of Human Model Implanted with Medical Metal Plates in Head Exposed to UHF Electromagnetic Fields  [Not invited]
    河村 由文, 日景 隆, 野島 俊雄
    電子情報通信学会技術研究報告 : 信学技報  2012/09
  • Local SAR Estimation of Human Model Implanted with Medical Metal Plates in Head Exposed to UHF Electromagnetic Fields  [Not invited]
    KAWAMURA Yoshifumi, HIKAGE Takashi, NOJIMA Toshio, NAGAOKA Tomoaki, WATANABE Soichi
    IEICE technical report. Electromagnetic compatibility  2012/08 
    The RF exposure guidelines do recognize that an increased local SAR (Specific Absorption Rate) due to metallic implants is possible, depending upon the size and shape of the implant and the position. In this study, the effect of medical metal plates in the head region is examined. An anatomical Japanese male adult and a simplified multi-layer flat model are used which the plates are implanted in mandibular zone. The local SAR dependencies due to the size variation of the metal plates were presented. In addition, a half-wave dipole antenna was used as an exposure source and the SAR in the near field was studied. The results indicated that some of the metal plates, under 2 GHz far-field and near-field exposure conditions, may cause a 37% increment of 10g averaged SAR.
  • B-1-22 Electric Characteristics of Cabin Sidewall Panel in Large Passenger Aircrafts : Dielectric Constant Measurements of Phenol FRP  [Not invited]
    FUTATSUMORI Shunichi, KOHMURA Akiko, ISOZAKI Eiju, YONEMOTO Naruto, HIKAGE Takashi, NOJIMA Toshio
    Proceedings of the Society Conference of IEICE  2012/08
  • B-4-19 In vitro Assessments of Active Implantable Medical Devices EMI from Radio Wave Emitted by LTE Wireless Devices  [Not invited]
    KAWAMURA Yoshifumi, HIKAGE Takashi, NOJIMA Toshio, FUJIMOTO Hiroshi, TOYOSHIMA Takeshi
    Proceedings of the Society Conference of IEICE  2012/08
  • 磁界共振型ワイヤレス電力伝送アンテナによる植込み型医療機器EMIの数値評価法 (エレクトロニクスシミュレーション)  [Not invited]
    鈴木 琢馬, 河村 由文, 日景 隆
    電子情報通信学会技術研究報告 : 信学技報  2012/07
  • 大規模FDTD解析を用いた航空機における無線LAN電波の伝搬特性評価 (エレクトロニクスシミュレーション)  [Not invited]
    木下 真樹, 日景 隆, 野島 俊雄
    電子情報通信学会技術研究報告 : 信学技報  2012/07
  • Estimation of Propagation Characteristics of Wireless LAN on Aircraft Using Large Scale FDTD Analysis  [Not invited]
    KINOSHITA Masaki, HIKAGE Takashi, NOJIMA Toshio, FUTATSUMORI Syunichi, KOHMURA Akiko, YONEMOTO Naruto
    電気学会研究会資料. EMT, 電磁界理論研究会  2012/07
  • Numerical Assessment Methodology for Active Implantable Medical Device EMI due to Magnetic Resonance Wireless Power Transmission Antenna  [Not invited]
    SUZUKI Takuma, KAWAMURA Yoshifumi, HIKAGE Takashi, NOJIMA Toshio
    電気学会研究会資料. EMT, 電磁界理論研究会  2012/07
  • Propagation Characteristic Estimations of Wireless Links in High-Speed Train Cars Based upon FDTD Analysis  [Not invited]
    白船 雅巳, 日景 隆, 野島 俊雄
    電子情報通信学会技術研究報告 : 信学技報  2012/07
  • Numerical Assessment Methodology for Active Implantable Medical Device EMI due to Magnetic Resonance Wireless Power Transmission Antenna  [Not invited]
    SUZUKI Takuma, KAWAMURA Yoshifumi, HIKAGE Takashi, NOJIMA Toshio
    電子情報通信学会技術研究報告. MWP, マイクロ波・ミリ波フォトニクス  2012/07 
    This paper introduces a numerical assessment methodology of the EMI triggered by magnetic resonance wireless power transmission(WPT) antennas and imposed on active implantable medical devices such as implantable-cardiac pacemakers and cardioverter defibrillators. A numerical estimation model that consists of magnetic resonant coils and a human torso phantom is constructed. Interference voltage induced at the connector of the pacemaker inside the human phantom is calculated using Finite element method(FEM). We consider, as an example, magnetic resonance WPT antennas operating the frequency band of 10MHz.
  • Estimation of Propagation Characteristics of Wireless LAN on Aircraft Using Large Scale FDTD Analysis  [Not invited]
    KINOSHITA Masaki, HIKAGE Takashi, NOJIMA Toshio, FUTATSUMORI Syunichi, KOHMURA Akiko, YONEMOTO Naruto
    電子情報通信学会技術研究報告. MWP, マイクロ波・ミリ波フォトニクス  2012/07 
    Recently, some airlines have begun in-flight wireless LAN service. The aim of this study is to develop an accurate and reliable method of estimating the electromagnetic field(EMF) distributions in aircraft cabins, which can contribute to advance the radio link design in support of such services. Previously, authors estimated propagation characteristics of cellular radio inside a typical aircraft cabin using a large scale FDTD computation. In this report, we estimate propagation characteristics of a 2.45GHz wireless LAN access point inside the cabin of a Boeing 777-200 model.
  • Propagation Characteristic Estimations of Wireless Links in High-Speed Train Cars Based upon FDTD Analysis  [Not invited]
    SHIRAFUNE Masami, HIKAGE Takashi, NOJIMA Toshio, YAMADA Wataru, SUGIYAMA Takatoshi
    IEICE technical report. Antennas and propagation  2012/07 
    The aim of this study is to develop an accurate and reliable method of estimating field (EMF) distributions in train cars so as to advance radio link design of wireless LANs operated inside the cars. This paper uses FDTD technique and a large-scale parallel computing technique to estimate the propagation characteristics of the high-speed train cars model. EMF distributions created by a 2.4GHz wireless transmitter inside cars are analyzed and propagation characteristics are determined from the analysis results. Additionally, in order to estimate the effect of the absorption by the passengers' bodies, we derive simplified histograms of the electric field distributions throughout the whole interior of the car.
  • Experimental Estimation of EMI from Electronic Article Surveillance on Implantable Cardiac Pacemakers and Implantable Cardioverter Defibrillators : Interference Distance and Clinical Estimation  [Not invited]
    河村 由文, 日景 隆, 野島 俊雄
    Transactions of Japanese Society for Medical and Biological Engineering  2012/06 
    Methods and results of in vitro experiments examining the electromagnetic interference (EMI) imposed on active implantable medical devices (AIMDs) by electronic article surveillance (EAS) systems are presented. Examined EAS systems include eleven models provided by four manufacturers. They are classified into four categories according to operating principle, and consist of one magnetic-type system, four acousto-magnetic type systems, five electromagnetic-type systems, and one microwave-type system. Examined AIMDs include five models of implantable cardiac pacemakers and five models of implantable cardioverter defibrillators (ICDs) provided by six manufacturers. These EAS systems and AIMDs are currently available in the Japanese market. The in vitro test system is based upon Irnich's flat torso phantom. The observed EMI on pacemakers is either missing pulses or undesirable generation of asynchronous pulses. The observed EMI on ICDs are inappropriate tachyarrhythmia detection and erroneous delivery of therapy. To summarize the results, in the worst case for pacemakers, interference occurred when approaching the EAS system up to 90 cm and entering the gate of the EAS system. The most significant effect was complete omission of pacing pulse and continuous generation of asynchronous pulses. These were observed when the pacemaker was set at maximum sensitivity. In the worst case for ICDs, interference occurred when approaching the EAS pedestal up to 90 cm within the gate. The most significant effect was inappropriate or inhibited tachyarrhythmia detection at 60 cm. These effects were drastically suppressed when the sensitivity was reduced and when the AIMD was far from the EAS system and magnetic field was attenuated. All AIMDs that experienced EMI returned to normal operation mode upon departing the EAS system.
  • Development of DNA markers that discriminate between white- and blue-flowers in Japanese gentian plants  [Not invited]
    NAKATSUKA Takashi, SAITO Misa, SATO-USHIKU Yuka, YAMADA Eri, NAKASATO Takashi, HOSHI Nobue, FUJIWARA Kazumichi, HIKAGE Takashi, NISHIHARA Masahiro
    Euphytica  2012/04
  • B-1-50 Propagation Characteristics for Wireless Communications in High-Speed Train Cars  [Not invited]
    HIKAGE Takashi, SHIRAFUNE Masami, NOJIMA Toshio, YAMADA Wataru, SUGIYAMA Takatoshi
    Proceedings of the IEICE General Conference  2012/03
  • B-4-44 Direction-of-Arrival Dependence Analysis of Local SAR of Human Model Implanted with Medical Metal Plates in Head  [Not invited]
    KAWAMURA Yoshifumi, HIKAGE Takashi, NOJIMA Toshio, NAGAOKA Tomoaki, WATANABE Soichi
    Proceedings of the IEICE General Conference  2012/03
  • FDTD Analysis of Propagation Characteristics of Wireless Communications in Crowded Train Cars  [Not invited]
    HIKAGE Takashi, IRIE Yohei, NOJIMA Toshio, YAMADA Wataru, SUGIYAMA Takatoshi
    電子情報通信学会技術研究報告. A・P, アンテナ・伝播  2012/01 
    Recently, some railway companies have begun in-car wireless LAN service. The aim of this study is to develop an accurate and reliable method of estimating electromagnetic field (EMF) distributions in train cars so as to advance radio link design of wireless LANs operated inside the cars. This paper uses FDTD technique and a large-scale parallel computing technique to estimate the propagation characteristics of the typical train car model. EMF distributions created by a 5.2 GHz wireless transmitter inside the train car are analyzed and propagation characteristics are determined from the anal...
  • Numerical estimation of the electric field distributions due to mobile radio in an aircraft cabin based on large scale FDTD analysis  [Not invited]
    Takashi Hikage, Shinya Hiraiwa, Toshio Nojima, Shunichi Futatsumori, Akiko Kohmura, Naruto Yonemoto
    Proceedings of EMC Europe 2011 York - 10th International Symposium on Electromagnetic Compatibility  2011/12 
    The aim of this study is to develop an accurate and reliable method that can estimate the electromagnetic field distributions in aircraft while contributing to the field of numerical EMI assessment. This paper describes large-scale numerical simulations of the electromagnetic fields excited by 800 MHz cellular radio inside an aircraft. We use a typical aircraft model and employ the parallel FDTD technique to estimate field distributions throughout the cabin. Computational results of the 1-dimensional electric field distribution inside the cabin agree well with measured values. In order to estimate the effect of absorption by the passengers' bodies inside the cabin, cumulative probabilities for field distributions are derived. ? 2011 EMC Europe.
  • Applicability Evaluation of Flat Torso Phantom with Back Absorbing Plate for Active Implantable Medical Devices' EMI Test Based on FDTD Analysis  [Not invited]
    IRIE Yohei, KAWAMURA Yoshifumi, HIKAGE Takashi, NOJIMA Toshio
    電気学会研究会資料. EMC, 電磁環境研究会  2011/12
  • Applicability Evaluation of Flat Torso Phantom with Back Absorbing Plate for Active Implantable Medical Devices' EMI Test Based on FDTD Analysis  [Not invited]
    IRIE Yohei, KAWAMURA Yoshifumi, HIKAGE Takashi, NOJIMA Toshio
    電子情報通信学会技術研究報告. EMCJ, 環境電磁工学  2011/12 
    The purpose of this research is to develop a new human torso phantom that provides more reliable estimations for active implantable medical devices (AIMDs) EMI due to UHF Radio Frequency Identification (RFID) interrogators. We proposed the phantom with an electromagnetic-field absorbing plate attached to the back of the AIMD in order to suppress standing waves, and estimated electromagnetic strength inside the phantom due to plane wave operating at 950 MHz and 2.45 GHz. In this paper, the effect of suppressing the standing waves inside the phantom due to radio waves emitted from a dipole antenna is estimated by using FDTD method.
  • Numerical estimation of RF propagation characteristics of cellular radio in an aircraft cabin  [Not invited]
    Masaki Kinoshita, Takashi Hikage, Toshio Nojima, Shunichi Futatsumori, Akiko Kohmura, Naruto Yonemoto
    Asia-Pacific Microwave Conference Proceedings, APMC  2011/12 
    This paper describes large-scale numerical simulations of the electromagnetic fields excited by cellular radio inside an aircraft. We use a typical aircraft model and employ the parallel FDTD technique to estimate field distributions throughout the cabin. In order to validate the analysis results, the calculated electric field distributions are compared to actual field measurements in a Boeing 777-200 aircraft. Computational results of the 1-dimensional electric field distribution inside the cabin agree well with measured values. Furthermore, a simplified histogram estimation method for electric field strength in the cabin was employed to deal with the complicated EMF distributions inside the cabin. ? 2011 Engineers Australia.
  • Numerical estimation methodology for RFID/Active Implantable Medical Device-EMI based upon FDTD analysis  [Not invited]
    Takashi Hikage, Yoshifumi Kawamura, Toshio Nojima
    2011 30th URSI General Assembly and Scientific Symposium, URSIGASS 2011  2011/11 
    A numerical estimation methodology for RFID /Active Implantable Medical Device (AIMD) EMI based upon FDTD analysis is presented. This methodology can be applied to low-band RFID. In this paper, an example for RFID interrogator in the frequency band of 13.56 MHz (ISO/IEC 18000-3 MODE 1) is shown. It assumes that RFID interrogators operating in the low or HF frequency bands might cause EMI on the AIMDs through the interference voltage induced by the magnetic flux excited by the RFID interrogator. Calculated interference voltage was compared with the EMI characteristics obtained by in-vitro EMI experiments to validate the analysis result. The estimated EMI characteristics obtained by the experiments and the FDTD analysis agreed well. ? 2011 IEEE.
  • Flat Torso Phantom with Back Absorbing Plate for EMI Test on Active Implantable Medical Devices  [Not invited]
    IRIE Yohei, KAWAMURA Yoshifumi, HIKAGE Takashi, NOJIMA Toshio
    IEICE technical report. Electromagnetic compatibility  2011/09 
    The purpose of this research is to develop a new human torso phantom that provides more reliable estimations for active implantable medical devices (AIMDs) EMI due to UHF Radio Frequency Identification (RFID) interrogators. The phantom has an electromagnetic-field absorbing plate attached to the back of the AIMD in order to suppress standing waves inside the phantom. In this paper, induced voltage at connector of an implantable cardiac pacemaker due to radio waves emitted from the RFID interrogators operating at 950 MHz and 2.45 GHz is estimated by using FDTD method. In addition, the induce...
  • Estimations of Implantable Cardiac Pacemaker EMI due to Magnetic Resonant Coil for Wireless Power Transfer Using FDTD Analysis  [Not invited]
    KINOSHITA Masaki, HIKAGE Takashi, NOJIMA Toshio
    IEICE technical report. Electromagnetic compatibility  2011/09 
    The purpose of our research is to develop a numerical electromagnetic interference (EMI) estimation method for Active Implantable Medical Device due to wireless power transmission antennas. Wireless Power Transmission technology using near-field magnetic coupling have been expected to achieve various applications (e.g. contactless electric vehicle (EV) charger). However, electromagnetic fields from these devices raises concern that they may cause other electronic devices to malfunction. Accordingly, investigations of EMI have been more important. In particular, EMI effects on medical equipm...
  • B-1-22 Estimation of Propagation Characteristics of Cellular Radio in an Aircrafi Cabin Using FDTD Method  [Not invited]
    KINOSHITA Masaki, HIKAGE Takashi, NOJIMA Toshio, FUTATSUMORI Shunichi, KOHMURA Akiko, YONEMOTO Naruto
    Proceedings of the Society Conference of IEICE  2011/08
  • B-4-14 Standing Wave Suppression inside Flat Torso Phantom for EMI Test on Active implantable medical devices  [Not invited]
    IRIE Yohei, KAWAMURA Yoshifumi, HIKAGE Takashi, NOJIMA Toshio
    Proceedings of the Society Conference of IEICE  2011/08
  • BI-3-4 Experimental Estimation and Mitigation Technique for Active Implantable Medical Devices EMI from RFID Interrogators  [Not invited]
    KAWAMURA Yoshifumi, FUTATSUMORI Shunichi, HIKAGE Takashi, NOJIMA Toshio, KOIKE Ben, FUJIMOTO Hiroshi, TOYOSHIMA Takeshi
    Proceedings of the Society Conference of IEICE  2011/08
  • Active implantable medical device EMI assessments for electromagnetic emitters operating in various RF bands  [Not invited]
    Takashi Hikage, Yoshifumi Kawamura, Toshio Nojima, Ben Koike, Hiroshi Fujimoto, Takeshi Toyoshima
    2011 IEEE MTT-S International Microwave Workshop Series on Innovative Wireless Power Transmission: Technologies, Systems, and Applications, IMWS-IWPT 2011 - Proceedings  2011/07 
    This paper describes the electromagnetic interference (EMI) characteristics of active implantable medical devices based on assessments of Radio Frequency Identification interrogators. Typical examples of interrogators operating in various RF bands are tested to estimate the EMI experienced by implantable-cardiac pacemakers and -cardioverter-defibrillators. The EMI occurrence mechanism and some experimental EMI evaluation results for typical devices are shown. Observed characteristics of the EMI are discussed based upon the transmission radio wave specifications. This discussion can give a good perspective on the same EMI issue raised by wireless power transmission systems. ? 2011 IEEE.
  • B-1-25 Propagation Characteristics in Crowded Train Cars for Wireless Communications  [Not invited]
    HIKAGE Takashi, OKAMURA Ryohei, NOJIMA Toshio, YAMADA Wataru, SUGIYAMA Takatoshi
    Proceedings of the IEICE General Conference  2011/02
  • B-4-18 FDTD Analysis Using Precise Numerical Human Models to Verify the Experimental Whole-Body Averaged SAR Estimation Method  [Not invited]
    KAWAMURA Yoshifumi, HIKAGE Takashi, NOJIMA Toshio, NAGAOKA Tomoaki, WATANABE Soichi
    Proceedings of the IEICE General Conference  2011/02
  • Numerical estimation of EMI impact on implantable cardiac pacemakers in elevator using EMF distributions inside human body  [Not invited]
    Takashi Hikage, Toshio Nojima, Ally Y. Simba, Soichi Watanabe
    2010 IEEE International Symposium on Antennas and Propagation and CNC-USNC/URSI Radio Science Meeting - Leading the Wave, AP-S/URSI 2010  2010/11 
    In recent years, mobile phone usage has extended to a wide range of environment such as places surrounded by conductive surfaces, e.g., train carriages, elevators, and airplanes. There have been concerns that cellular radio can interfere with different types of devices and increased usage in multi-reflection environments has led to concern about the possible effect of electromagnetic interference (EMI) on implantable medical devices (IMDs). Many experimental studies have been carried out in order to assess the EMI generated by cellular radio in free-space and experienced by IMDs including implantable cardiac pacemakers and implantable cardioverter defibrillators (ICDs) [1]-[3]. However, few studies have addressed the effect of EMI on IMDs in elevators. Precise and efficient methods of measuring the electric field (E-field) strength in different regions of multi-reflection environments have not been advanced due to the disturbed fields caused by the presence of measurement equipment and/or human bodies. Therefore, this is achieved by carrying out precise numerical simulations using the Finite-Difference-Time-Domain method [4]. We have already carried out numerical simulations on homogeneous human phantom models and some elevator models to investigate the EMI impact to implantable cardiac pacemakers in elevators; we examined the E-field distribution on the horizontal plane inside elevator [5], outside of human body. In this paper, we introduce our method for estimating pacemaker EMI using EMF distributions inside the region of the human body into which pacemakers are implanted. This enables us to carry out quantitative evaluations of the EMI impact to pacemakers by cellular radio transmission. In order to examine the complex situations where human is present in elevators, our analysis considered a realistically-shaped and anatomically-correct human phantom model. All calculations were run on a supercomputer. ? 2010 IEEE.
  • Estimation on Electric Field Distribution Emitted by Mobile Phone Inside an Elevator Using FDTD Method with Applied Perfect Electric Conductor Boundary Condition  [Not invited]
    OKAMURA Ryohei, HIKAGE Takashi, NOJIMA Toshio, SIMBA Ally Y, WATANABE Soichi
    電気学会研究会資料. EMC, 電磁環境研究会  2010/09
  • Large Scale FDTD Analysis on Propagation Characteristics of Cellular Radio in Aircraft Cabin  [Not invited]
    HIRAIWA Shinya, HIKAGE Takashi, NOJIMA Toshio, FUTATSUMORI Syunichi, KOHMURA Akiko, YONEMOTO Naruto
    電気学会研究会資料. EMC, 電磁環境研究会  2010/09
  • Estimation of Direction-of-Arrival Dependence of Whole-Body Averaged SAR in Japanese Human Models Exposed to Plane-Wave  [Not invited]
    KOBAYASHI Noriyuki, KAWAMURA Yoshifumi, HIKAGE Takashi, NOJIMA Toshio, NAGAOKA Tomoaki, WATANABE Soichi
    電気学会研究会資料. EMC, 電磁環境研究会  2010/09
  • FDTD Analysis of implantable medical device EMI due to near field generated around HF RFID reader/writers : Magnetic near-field distribution dependence  [Not invited]
    KIKUYA Atsushi, HIKAGE Takashi, NOJIMA Toshio, KOIKE Ben, FUJIMOTO Hiroshi, TOYOSHIMA Takeshi
    電気学会研究会資料. EMC, 電磁環境研究会  2010/09
  • B-1-23 Analysis of Polarization Characteristics in an Airplane Using FDTD Method  [Not invited]
    HIRAIWA Shinya, HIKAGE Takashi, NOJIMA Toshio, FUTATSUMORI Shunichi, KOHMURA Akiko, YONEMOTO Naruto
    Proceedings of the Society Conference of IEICE  2010/08
  • Estimation on Electric Field Distribution Emitted by Mobile Phone Inside an Elevator Using FDTD Method with Applied Perfect Electric Conductor Boundary Condition  [Not invited]
    OKAMURA Ryohei, HIKAGE Takashi, NOJIMA Toshio, Simba Ally Y, WATANABE Soichi
    IEICE technical report. Electromagnetic compatibility  2010/08 
    The purpose of this study is to estimate the electric field distributions emitted by mobile phone inside environments surrounded by conductive surfaces, for example, train carriages or elevators, using FDTD method. We previously investigated the electric field distribution inside elevator in analysis that modeled human body and elevator in high accuracy. In this paper, perfect electric conductor boundary (i.e. the infinite mirror reflection) condition is applied to achieve quantitative estimation for attenuation characteristics of RF field excited by mobile radio in an elevator. As a result...
  • Large Scale FDTD Analysis on Propagation Characteristics of Cellular Radio in Aircraft Cabin  [Not invited]
    HIRAIWA Shinya, HIKAGE Takashi, NOJIMA Toshio, FUTATSUMORI Syunichi, KOHMURA Akiko, YONEMOTO Naruto
    IEICE technical report. Electromagnetic compatibility  2010/08 
    Recently, some airlines have begun allowing in-flight voice calls. On the other hand, some paper reported that electromagnetic interference (EMI) to aircraft systems from active radio transmitters is possible. The aim of this study is to develop accurate and reliable estimation method of electromagnetic field distributions in aircraft that can contribute to numerical EMI assessment technique. In this report, large-scale numerical simulations are carried out to examine the electromagnetic fields excited by the 800 MHz cellular radio inside an aircraft. We used a typical aircraft model and em...
  • Estimation of Direction-of-Arrival Dependence of Whole-Body Averaged SAR in Japanese Human Models Exposed to Plane-Wave  [Not invited]
    KOBAYASHI Noriyuki, KAWAMURA Yoshifumi, HIKAGE Takashi, NOJIMA Toshio, NAGAOKA Tomoaki, WATANABE Soichi
    IEICE technical report. Electromagnetic compatibility  2010/08 
    Whole-body averaged specific absorption rate (WB-SAR) in realistic human models exposed to RF plane-wave has been estimated by numerical calculations. WB-SAR estimations using numerical calculation exhibit some variations due to difference in human shape or program code in several laboratories. On the other hand, there seems to be no experimental studies which have reported highly accurate and reproducible results for realistic shaped human models. We have proposed a novel WB-SAR estimation method based on external-cylindrical fields scanning technique and carried out measurements using rea...
  • FDTD Analysis of implantable medical device EMI due to near field generated around HF RFID reader/writers : Magnetic near-field distribution dependence  [Not invited]
    KIKUYA Atsushi, HIKAGE Takashi, NOJIMA Toshio, KOIKE Ben, FUJIMOTO Hiroshi, TOYOSHIMA Takeshi
    IEICE technical report. Electromagnetic compatibility  2010/08 
    Electromagnetic interference (EMI) from Radio Frequency Identification (RFID) reader/writers on implantable medical devices (IMD) is investigated. The purpose of our research is to study a numerical EMI estimation method. In this paper, a numerical EMI estimation methodology based upon finite-difference time-domain (FDTD) analysis is presented. The RFID/IMD-EMI discussed in this paper is implantable medical device EMI due to HF (13.56 MHz) RFID reader/writers. Some numerical HF RFID reader/writer antenna models and a human torso phantom model including pacemaker and lead wire are presented....
  • Whole-body averaged SAR Measurement based on electric field distributions on external cylindrical boundary  [Not invited]
    Takashi Hikage, Yoshifumi Kawamura, Toshio Nojima
    EuCAP 2010 - The 4th European Conference on Antennas and Propagation  2010/08 
    The aim of this study is to develop a new whole-body averaged specific absorption rate (SAR) measurement system based on the external-cylindrical field scanning technique. This technique is adopted with the goal of simplifying the dosimetry estimation of human phantoms that have different postures or sizes. An experimental scale model system is constructed. We consider the anatomical European human phantom and planewaves in the 2 GHz mobile phone frequency band. The measured whole-body averaged SAR results yielded by the proposed method are compared with the results of the FDTD analyses.
  • B-1-5 Inter-car Propagation Characteristics for Wireless communications in Train cars  [Not invited]
    HIKAGE Takashi, KITAGAWA Atsushi, NOJIMA Toshio, YAMADA Wataru, SUGIYAMA Takatoshi
    Proceedings of the IEICE General Conference  2010/03
  • B-4-48 Whole-Body Averaged SAR Estimation for Postured Japanese Numerical Human Models  [Not invited]
    KAWAMURA Yoshifumi, HIKAGE Takashi, NOJIMA Toshio, NAGAOKA Tomoaki, WATANABE Soichi
    Proceedings of the IEICE General Conference  2010/03
  • Effect of passive RF exposure from mobile phones on passengers inside an elevator: Comparison between adult and child passengers  [Not invited]
    All Y. Simba, Soichi Watanabe, Takashi Hikage, Toshio Nojima
    2nd International Symposium on Applied Sciences in Biomedical and Communication Technologies, ISABEL 2009  2009/12 
    This paper compares the effect of passive rf exposure on the specific absorption rate and absorbed power of an adult and a child passenger without phones inside an elevator when several other passengers are using their mobile phones simultaneously. The absorbed power and SAR were calculated using finite-difference time-domain. The mobile phones were modeled as half-wavelength dipole antenna placed at the distance of 16 mm from the head, with a transmitting power of 0.25 W. Our results show that child passenger without phone absorbs more power passively as compared to adult passenger. For the case when non-user passenger is surrounded by five passengers using mobile phones, power of 118 and 218 mW were absorbed by the adult and child models, respectively, implying that the passive rf exposure depends on the size of the passengers. Furthermore, the maximum values of the whole-body SARs due to passive exposure are obtained in this work are much smaller than the ICNIRP basic restriction. ?2009 IEEE.
  • A novel method of mitigating EMI on implantable medical devices: Experimental validation for UHF RFID reader/writers  [Not invited]
    Yoshifumi Kawamura, Shunichi Futatsumori, Takashi Hikage, Toshio Nojima, Ben Koike, Hiroshi Fujimoto, Takeshi Toyoshima
    IEEE International Symposium on Electromagnetic Compatibility  2009/12 
    A method of mitigating the electromagnetic interference (EMI) due to wireless communication devices on im-plantable medical devices (IMDs) such as implantable cardiac-pacemakers and implantable cardioverter-defibrillators (ICDs) is newly proposed. The key feature of the proposed method is that it does not require any modification of the IMDs. This method is based on the use of a "mitigation signal" which lies in the idle periods of the wireless communication device. By using this mitigation signal, the low frequency noise signal generated in the IMDs' internal circuits by nonlinear detection, can be reduced. This leads to a drastic improvement in the maximum interference distance. The proposed method is experimentally confirmed in this paper as applied to UHF RFID reader/writers. First, the proposed EMI mitigation method is detailed. An implementation of the method for UHF RFID reader/writers is then presented. The in vitro EMI experiment uses 3 types of actual implantable cardiac pacemakers. Finally, the mitigation results are shown. The results show the proposed method can greatly shorten the maximum interference distance by more than 90 % for all pacemakers. For example, the maximum interference distance of one pacemaker is reduced by 68 cm, from 71 cm to 3 cm. ? 2009 IEEE.
  • A review of mobile phone usage in enclosed areas and RF safety guideline  [Not invited]
    Ally Y. Simba, Soichi Watanabe, Takashi Hikage, Toshio Nojima
    IEEE AFRICON Conference  2009/12 
    The use of mobile phones in metallic enclosed environments such as elevators, train cars and even airplanes has attract a lot of attention in recent years. In these environments, most of the radio frequency (RF) energy from mobile phones remains inside due to the lack of escape routes, resulting in possibility of the field levels exceeding limits described in the international RF safety guidelines. This has resulted in an anxiety on possible health effects of passengers in these environments. In this review paper, size of the passengers (child vs. adult human model), method of investigation (theory vs. numerical), passenger position, elevator structure etc., are briefly discussed to determine how they affect the RF exposure. We also discuss few experimental investigation related to this problem for the passenger using a mobile phone near a metallic wall. Our objective is to provide an understanding of the SAR characteristics of the mobile phone user in such environment and how these characteristics are affected by the aforementioned factors. ? 2009 IEEE.
  • Whole-body averaged SAR measurement method using cylindrical scanning of external electromagnetic fields  [Not invited]
    Takashi Hikage, Yoshifumi Kawamura, Toshio Nojima
    2009 International Symposium on Electromagnetic Compatibility - EMC Europe  2009/11 
    The final goal of this study is to experimentally estimate the whole-body averaged specific absorption rate (SAR) of humans using the radiation-field scanning technique and a silicone rubber phantom. Dosimetry estimations for human exposure including very numerically accurate phantom models have been reported. However, due to the difficulty of measuring the SAR over the whole human body for the purpose of assessing electromagnetic RF exposure, few investigations have used realistically shaped human phantom models. In this paper, a novel whole-body averaged SAR estimation method based on the power consumption obtained by measuring the radiated power from cylindrical surfaces including humans and the exposure equipment is proposed. Validity of the proposed method based on cylindrical fields scanning is investigated using Finite-Difference Time-Domain (FDTD) calculations for the purpose of designing and developing the experimental system. The calculated whole-body averaged SAR yielded by the proposed method is compared with that obtained by standard calculation methods. ? 2009 IEEE.
  • C-1-18 An International Inter-laboratory Comparison of SAR Calculation with Virtual Family Model  [Not invited]
    Hikage Takashi, Kitagawa Atsushi, Nojima Toshio
    Proceedings of the Society Conference of IEICE  2009/09
  • B-4-3 Development of a Quasi-Microwave Whole-Body SAR Estimation System using the Cylindrical-External Electric-Field Scanning  [Not invited]
    KAWAMURA Yoshifumi, HIKAGE Takashi, NOJIMA Toshio
    Proceedings of the Society Conference of IEICE  2009/09
  • B-4-15 Whole-Body Averaged SAR Estimation Method using Cylindrical Scanning of External Electromagnetic Fields  [Not invited]
    KAWAMURA Yoshifumi, HIKAGE Takashi, NOJIMA Toshio
    Proceedings of the IEICE General Conference  2009/03
  • B-1-16 Numerical Analysis of Indoor Propagation of Plane Wave Incident from Side Walls  [Not invited]
    Hasegawa Tomotsugu, Shoji Tomohito, Omiya Manabu, Hikage Takashi
    Proceedings of the IEICE General Conference  2009/03
  • CS-3-6 ACLR and power efficiency improvements of GaN HEMT power amplifiers using a 5-GHz hightemperature superconducting reaction-type transmitting filter  [Not invited]
    FUTATSUMORI Shunichi, HIKAGE Takashi, NOJIMA Toshio, AKASEGAWA Akihiko, NAKANISHI Teru, YAMANAKA Kazunori
    Proceedings of the IEICE General Conference  2009/03
  • Specific absorption rates of anatomically realistic human models exposed to RF electromagnetic fields from mobile phones used in elevators  [Not invited]
    Ally Y. Simba, Takashi Hikage, Soichi Watanabe, Toshio Nojima
    IEEE Transactions on Microwave Theory and Techniques  2009/01 
    This paper presents a detailed numerical investigation to determine whether or not an increased specific absorption rate (SAR) in an adult using a mobile phone inside an elevator due to the multireflections of electromagnetic fields from the walls exceed the RF-exposure guidelines. A fully realistic heterogeneous human body model and an actual elevator size were employed. The nonuniform mesh finite-difference time-domain technique and a supercomputer were employed to obtain the SAR and other important parameters. The mobile phone was modeled as a λ/2 dipole antenna placed at a distance of 16 mm from the head. For computations, operating frequencies of 900, 1500, and 2000 MHz with transmitting power of 250 mW were used. Computed results show that the peak spatial-average 10-g SAR depends on the position of the passenger and the antenna against the elevator walls. We observed a substantial increase in the whole-body average SAR and peak 10-g SAR values of the passenger in the elevator over their respective free-space values. However, the maximum values obtained do meet the basic restrictions described in the international RF safety guidelines. For example, the maximum values of the whole-body average and peak spatial-average SAR were 4.4% and 78% of the international RF safety guideline, respectively. ? 2009 IEEE.
  • Effects of losses due to human phantoms on 3-dimensional Electromagnetic Field distribution in elevators  [Not invited]
    Y. Kawamaura, T. Hikage, T. Nojima, A. Simba, S. Watanabe
    Progress in Electromagnetics Research Symposium  2009/01 
    The purpose of this study is to estimate the Electromagnetic field (EMF) distributions emitted by Cellular radios in environments surrounded by conductive surfaces, e.g., elevators using precise numerical analysis based on the FDTD method. Since portable radios may be used in various environments, accurate and reliable estimations of EMF in practical environments are required. In this paper, we discuss the EMF absorption effects due to lossy materials being present in elevators. Simplified field histograms and cumulative ratios are derived from 3-dimensional EMF distributions throughout the inner space of the elevator. The lossy material consisted of almost the same volume as a human body and can decrease the strength of EMF distributions inside the elevator by about 20 dB.
  • A Novel Filter Construction Utilizing HTS Reaction-Type Filter to Improve Adjacent Channel Leakage Power Ratio of GaN HEMT Power Amplifiers  [Not invited]
    FUTATSUMORI Shunichi, HIKAGE Takashi, NOJIMA Toshio, AKASEGAWA Akihiko, NAKANISHI Teru, YAMANAKA Kazunori
    IEICE technical report. Microwaves  2008/12 
    We propose a new band selective stop filter construction to decrease the out of band intermodulation distortion (IMD) noise generated in the transmitting power amplifier. Suppression of IMD noise directly improves the adjacent channel leakage power ratio (ACLR). Firstly, the structure of a 5-GHz split open-ring resonator is investigated. Then, a designed 5-GHz HTS-RTF with 4MHz suppression bandwidth and more than 40dB/MHz sharp skirt is fabricated and experimentally investigated. The measured ACLR values are improved by a maximum of 12.8dB and are constant up to the passband signal power of...
  • An experimental validation of a detailed numerical model for predicting implantable medical devices EMI due to low-band RFID reader/writers  [Not invited]
    Shunichi Futatsumori, Norihiro Toyama, Takashi Hikage, Toshio Nojima, Ben Koike, Hiroshi Fujimoto, Takeshi Toyoshima
    Proceedings of 2008 Asia Pacific Microwave Conference, APMC 2008  2008/12
  • Measurement of the maximum SAR in a spherical phantom when operating a mobile phone near a metallic wall  [Not invited]
    Ally Y. Simba, Soichi Watanabe, Takashi Hikage, Toshio Nojima
    2008 1st International Symposium on Applied Sciences in Biomedical and Communication Technologies, ISABEL 2008  2008/12 
    The aim of this paper is to present an experimental investigation of the specific absorption rate (SAR) in a spherical phantom head when operating a mobile phone close to a metallic wall. The mobile phone is modeled as a half-wavelength dipole antenna. The effect of the wall on the peak 10-g SAR and input characteristics of the antenna for two wall orientations are measured. The antenna is set to transmit maximum output power of 250 mW at 900 MHz. A slowly decaying sinusoidal form of the peak 10-g SAR curves, which has been predicted by numerical simulation from several authors including ourselves, is confirmed experimentally for the first time. Under the valid antenna-wall distances used in this work, maximum peak 10-g SAR increase of 7 % over the free space value was recorded at the distance of 394 mm away from the wall. Simulated results obtained by the FDTD technique are also presented. Good agreement between the measured and simulated results is obtained.
  • ACLR improvement of a 5-GHz power amplifier using high-temperature superconducting reaction-type transmitting filters  [Not invited]
    Shunichi Futatsumori, Takashi Hikage, Toshio Nojima, Akihiko Akasegawa, Teru Nakanishi, Kazunori Yamanaka
    Proceedings of the 38th European Microwave Conference, EuMC 2008  2008/12 
    Adjacent channel leakage power ratio (ACLR) improvement method of a 5-GHz power amplifier using high-temperature superconducting reaction-type transmitting filters (HTS-RTF) is proposed. The aim of this paper is to clarify the amount of ACLR improvement which is offered by HTS-RTFs. Firstly, measurement results of ACLR improvement using a prototype filter is introduced. The prototype filter has an about 10 dB improvement up to 40 dBm Wideband CDMA (W-CDMA) four-carrier signal, even though the suppression band is one side and the bandwidth is narrow. Secondly, to achieve wider suppression band, their resonator structures are optimized. The split-open ring resonator is modified to obtain higher unloaded Q-factor and lower current density. In addition, 5-GHz HTSRTFs which have 3.5 MHz suppression bands in both sides of the W-CDMA carrier signal are designed. Finally, the ACLR improvement obtained by the newly designed filter is estimated based on numerical analysis. The ACLR is improved by about 10 dB in the both sides. Furthermore, the results show that amplifiers' back-off can be reduced by 5 dB when the HTS-RTFs applied to power amplifiers. ? 2008 EuMA.
  • Numerical analysis of electromagnetic field distributions in a typical aircraft  [Not invited]
    Takashi Hikage, Toshio Nojima, Manabu Omiya, Kazuo Yamamoto
    IEEE International Symposium on Electromagnetic Compatibility  2008/12 
    The purpose of this study is to develop accurate and reliable estimation method of Electromagnetic field distributions in practical environments including passengers. However, comprehensive measurements in an actual environment cost too much and it is difficult to carry them out precisely. In this paper, large-scale numerical simulations are carried out to examine the electromagnetic fields excited by the 2.45 GHz wireless LAN terminal inside an aircraft. We used a typical aircraft model and employed the FDTD technique and a supercomputer to estimate the field distributions inside the whole area of the cabin. A Large-scale parallel computing technique based upon several node partitions of a supercomputer was used because of its memory and speed capabilities. It is able to give us a good perspective within a reasonable computation time. Furthermore, a simplified histogram estimation method for electric field strength in the cabin was employed to deal with the complicated EMF distributions inside the cabin including passengers. ? 2008 IEEE.
  • Estimations for Implantable Cardiac Pacemakers EMI from cellular radios in narrow space multi reflection environments  [Not invited]
    Takashi Hikage, Louis Ray Harris, Toshio Nojima, Simba Ally, Soichi Watanabe
    2008 Asia-Pacific Symposium on Electromagnetic Compatibility and 19th International Zurich Symposium on Electromagnetic Compatibility, APEMC 2008  2008/09 
    The reason for this study being done is to make an accurate estimate of how the Electromagnetic Field (EMF) is distributed in environments which are almost completely surrounded by conductive surfaces. Some examples of these types of environments are train carriages, elevators and airplanes. Upon analysis of the results, it would then be possible to investigate in further detail the likelihood of there being any effects by Electromagnetic Interference (EMI) on Implantable Cardiac Pacemakers in these kinds of environments, commonly referred to as Semi-Echoic environments.
  • C-2-84 ACLR improvements of a power amplifier using a 5-GHz high-temperature superconducting reaction-type transmitting filter  [Not invited]
    FUTATSUMORI Shunichi, HIKAGE Takashi, NOJIMA Toshio, AKASEGAWA Akihiko, NAKANISHI Teru, YAMANAKA Kazunori
    Proceedings of the Society Conference of IEICE  2008/09
  • B-1-5 Numerical Analysis of Oblique Incident Plane Wave Indoor Propagation  [Not invited]
    Hasegawa Tomotsugu, Shoji Tomohito, Omiya Manabu, Hikage Takashi
    Proceedings of the Society Conference of IEICE  2008/09
  • An Estimation of Cumulative Probability of Indoor Cross Polarization for Terrestrial Digital Broadcasting  [Not invited]
    HASEGAWA Tomotsugu, IWAMOTO Yoshinori, OMIYA Manabu, HIKAGE Takashi
    ITE Technical Report  2008/07 
    The digital terrestrial broadcasting services for mobile receivers had already been started in Japan. The service is effective as communication means at outbreaks of natural disaster. Experimental studies of the reception characteristic in various environments and countermeasures for the deterioration of reception are carried out until now. In this report, we consider the incidence plane wave of digital terrestrial broadcasting due to clarifying its indoor propagation characteristics. A large-scale numerical analysis by using the finite-difference time-domain technique is employed for this ...
  • An Estimation of Radiation Patterns of a Vehicle Mounted Antenna for Digital Terrestrial Broadcasting Reception  [Not invited]
    SHOJI Tomohito, MURAMOTO Mitsuru, HIKAGE Takashi, OMIYA Manabu
    ITE Technical Report  2008/07 
    To estimate on-vehicle antenna characteristics accurately, the surrounding environment such as the vehicle body form must be considered in measurements and numerical analysis. This report studies the vehicle model simplification related to radiation patterns of an inverted L antenna for receiving the digital terrestrial television mounted on the vehicle. The numerical evaluations are carried out by employing the FDTD technique. We clarify that the structure of roof and pillar must be considered in computing radiation patterns for four types of numerical model.
  • TOYAMA Norihiro, FUTATSUMORI Shunichi, HIKAGE Takashi, NOJIMA Toshio, KOIKE Ben, FUJIMOTO Hiroshi, TOYOSHIMA Takeshi
    IEICE technical report  2008/06  The Institute of Electronics, Information and Communication Engineers
     
    Electromagnetic interference (EMI) from Radio Frequency Identification (RFID) reader/writers on implantable medical devices is investigated. The purpose of our research is to study a numerical EMI estimation method. First, four high frequency (HF) RFID reader/writer antennas and numerical antenna models are constructed. In addition, obtained data of magnetic field distributions created around the antenna by using the finite-difference time-domain (FDTD) method and experimentally measured data are comparatively discussed. Next, EMI experiments are performed to obtain the maximum interference distance (distance where EMI disappears) with respect to antenna input power. Then, to validate the analysis results, the relation between the maximum interference distance (obtained by EMI experiments with an injected ECG signal) and the estimated induced voltage at the connector of the implantable cardiac pacemaker model are investigated. A numerical model of a human torso phantom and an implantable cardiac pacemaker are analyzed in order to estimate this voltage.
  • FDTD analysis of medical device interference due to near field generated around HF RFID reader/writers : Experimental validation based on EMI characteristics of actual devices  [Not invited]
    TOYAMA Norihiro, FUTATSUMORI Shunichi, HIKAGE Takashi, NOJIMA Toshio, KOIKE Ben, FUJIMOTO Hiroshi, TOYOSHIMA Takeshi
    電子情報通信学会技術研究報告. EMCJ, 環境電磁工学  2008/06 
    Electromagnetic interference (EMI) from Radio Frequency Identification (RFID) reader/writers on implantable medical devices is investigated. The purpose of our research is to study a numerical EMI estimation method. First, four high frequency (HF) RFID reader/writer antennas and numerical antenna models are constructed. In addition, obtained data of magnetic field distributions created around the antenna by using the finite-difference time-domain (FDTD) method and experimentally measured data are comparatively discussed. Next, EMI experiments are performed to obtain the maximum interference...
  • SAR Evaluation of the Reproductive Organ of Male Rats for 2GHz in vivo Experiments : Dosimetry Evaluation Using FDTD method  [Not invited]
    KAWAMURA Yoshifumi, HIKAGE Takashi, NOJIMA Toshio
    電子情報通信学会技術研究報告. EMCJ, 環境電磁工学  2008/06 
    In this paper, the specific absorption rates (SARs) of the reproductive organ of male rats are calculated by the simulation using the finite difference time domain (FDTD) method. There have been some publications concerning effects on some sperm profiles due to using cell phone. The experiments which is aim to investigate the influence that the electromagnetic radiation from cellular phone give the function of male reproductive organ are conducting by the Association of Radio Industries and Businesses in Japan. The purpose of this study is exposure dosimetry estimations for the experiments....
  • YAMANAKA Kazunori, KURIHARA Kazuaki, AKASEGAWA Akihiko, FUTATSUMORI Shunichi, HIKAGE Takashi, NOJIMA Toshio
    IEICE technical report  2008/04  The Institute of Electronics, Information and Communication Engineers
     
    For high temperature superconducting (HTS) power bandpass filters (BPFs), the developed resonator devices, the technology issues and promising application area are introduced. Furthermore, we report the preliminary results by numerical simulations on studying transmitter output spurious suppression effect using BPFs, i.e., spurious suppression effects were simulated numerically by difference of frequency selectivity of the model filers as a 5GHz-band modulated RF signal was inputted to RF power amplifier with the output-side model filter.
  • Spurious Suppression Effect by HTS power bandpass filters for 5GHz band  [Not invited]
    YAMANAKA Kazunori, KURIHARA Kazuaki, AKASEGAWA Akihiko, Futatsumori Shunichi, Hikage Takashi, Nojima Toshio
    Technical report of IEICE. SCE  2008/04 
    For high temperature superconducting (HTS) power bandpass filters (BPFs), the developed resonator devices, the technology issues and promising application area are introduced. Furthermore, we report the preliminary results by numerical simulations on studying transmitter output spurious suppression effect using BPFs, i.e., spurious suppression effects were simulated numerically by difference of frequency selectivity of the model filers as a 5GHz-band modulated RF signal was inputted to RF power amplifier with the output-side model filter.
  • C-2-94 ACLR improvement of a 5-GHz power amplifier using a high-temperature superconducting reactiontype transmitting filter  [Not invited]
    FUTATSUMORI Shunichi, HIKAGE Takashi, NOJIMA Toshio, AKASEGAWA Akihiko, NAKANISHI Teru, YAMANAKA Kazunori
    Proceedings of the IEICE General Conference  2008/03
  • 話題の追跡 RFID機器の医療機器に対する影響についての実験評価  [Not invited]
    日景 隆, 二ツ森 俊一, 野島 俊雄
    自動認識  2008/02
  • A novel assessment methodology for the EMI occurrence in implantable medical devices based upon magnetic flux distribution of RFID reader/writers  [Not invited]
    Shunichi Futatsumori, Takashi Hikage, Toshio Nojima, Ben Koike, Hiroshi Fujimoto, Takeshi Toyoshima
    IEEE International Symposium on Electromagnetic Compatibility  2007/12 
    With respect to the EMI affecting implantable medical devices caused by Radio Frequency Identification Reader/Writers (RFID R/W), experimental investigations are conducted to develop a risk assessment methodology based upon the measurement of the EMF distribution around RFID R/W. First, fundamental EMI occurrence mechanisms of implantable-cardiac pacemakers and -cardioverter-defibrillators (ICD) are described. Secondly, the characteristics of the radio wave emitted by the RFID R/W are described. Next, EMI test experiments and measurements of the field distributions are performed. Then, a novel experimental assessment methodology is proposed. The EMI characteristics derived from magnetic flux distributions are compared with the experimental results to confirm the effectiveness of the proposed methodology. Finally, it is shown that the probability of EMI occurrence can be estimated using the statistical processing of the proposed methodology. ? 2007 IEEE.
  • HTS reaction-type transmitting filter based upon split open-ring resonators with surface current density reduction technique  [Not invited]
    Shunichi Futastumori, Takashi Hikage, Toshio Nojima, Akihiko Akasegawa, Teru Nakanishi, Kazunori Yamanaka
    Asia-Pacific Microwave Conference Proceedings, APMC  2007/12 
    An High-Temperature Superconducting reaction-type transmitting filter (HTS-RTF) based upon split open-ring resonators with novel surface current density reduction technique is proposed. Since reaction-type resonators do not resonate with high-power fundamental signals, an HTS-RTF enables both high-power handling capability and steep skirt property compared to existing planar-type HTS transmitting filters. However, fundamental signals in the passband induce a current in their resonators. Firstly, to reduce induced currents in the passband, novel split open-ring resonator (SORR) structures that reduce maximum current densities while offering both high-unloaded Q-factors and low radiations are numerically investigated for 5-GHz band operation. Secondly, to further improve the current density dispersion effect, additional slits are introduced to the resonator surface. Then, to validate the analysis results, fabrications and measurements of the resonators are carried out. Measurements confirm an unloaded Q-factor of 68,000 and third intermodulation-distortion of -82 dBc at 30 dBm input power. Finally, design and fabrication of a 5-GHz three-pole reaction-type filter with bandwidth of 1.5 MHz (FBW = 0.03 %) is conducted. The measurement results confirm the fundamental performance of the filter.
  • Estimation of electric field distribution in wireless office LANS using the FDTD method  [Not invited]
    L. Harris, T. Hikage, T. Nojima
    IET Seminar Digest  2007/12 
    The purpose of this study is to examine the Electric Field distribution in wireless office LAN environments. The model used for this study is a common office environment which has objects of varying physical and electrical properties such as desks, chairs and bookshelves, among others.
  • A novel microwave high-temperature superconducting reaction-type transmitting filter for mobile base stations  [Not invited]
    Shunichi Futatsumori, Takashi Hikage, Toshio Nojima
    MSMW'07 Symposium Proceedings - The 6th International Kharkov Symposium on Physics and Engineering of Microwaves, Millimeter and Submillimeter Waves and Workshop on Terahertz Technologies  2007/12 
    A novel split open-ring reaction-type construction technique to achieve high power-handling capability for High-temperature superconducting (HTS) filters is presented. The purpose of this filter is to suppress the adjacent noise generated by transmitting power amplifiers for mobile base stations, First, it is explained that reaction-type filters are suitable for high power transmission. Secondly, novel split open-ring resonators, which reduce the maximum current density while maintaining high Q-factors are proposed. Current density dispersion effects are evaluated under the same coupling coefficient. Finally, a 5 GHz three-pole reaction-type filter using split open-ring resonators is designed. The frequency characteristics of the filter are investigated by using the method of moments. The results predict that the filter realizes both a higher power-handling capability than that of transmission-type filters and a better skirt property than existing HTS filters using dual-mode resonators. ? 2007 IEEE.
  • Development of lightweight solid phantom composed of silicone rubber and carbon nanotubes  [Not invited]
    Takashi Hikage, Yuki Sakaguchi, Toshio Nojima, Yuji Koyamashita
    IEEE International Symposium on Electromagnetic Compatibility  2007/12 
    A lightweight human phantom material that has a specific gravity below 1.0 is newly developed and a full sized realistic shaped human phantom model is constructed using this material. Fundamental material composites are carbon nanotubes and silicone rubber. The carbon nanotubes enable this material to simulate various biological tissues with less specific gravity values than those of original ones. In addition, using the silicone rubber allows us to construct phantom models of various shapes. This paper describes the design principle and estimates the relation between complex permittivity and composition ratio of the material experimentally. Finally, a full sized realistic shaped human phantom model is constructed to show the features of the proposed material. ? 2007 IEEE.
  • FDTD analysis of medical device interference due to near field generated around HF RFID reader/writers : Construction of numerical model and estimation of induced voltage  [Not invited]
    TOYAMA Norihiro, FUTATSUMORI Shunichi, HIKAGE Takashi, NOJIMA Toshio, KOIKE Ben, FUJIMOTO Hiroshi, TOYOSHIMA Takeshi
    電気学会研究会資料. EMC, 電磁環境研究会  2007/11
  • Estimation of Electromagnetic Field Distribution caused by Cellular Radios in Elevators Considering Human Absorption Effects  [Not invited]
    ABIKO Yusuke, HIRONO Masahiko, HIKAGE Takashi, NOJIMA Toshio
    電気学会研究会資料. EMC, 電磁環境研究会  2007/11
  • An experimental investigation on typical low frequency amplifiers nonlinear response to microwave/quasi-millimeter wave interference  [Not invited]
    SEO Hiroki, FUTATSUMORI Shunichi, HIKAGE Takashi, NOJIMA Toshio
    電気学会研究会資料. EMC, 電磁環境研究会  2007/11
  • Estimation of Electromagnetic Field Distribution caused by Cellular Radios in Elevators Considering Human Absorption Effects  [Not invited]
    ABIKO Yusuke, HIRONO Masahiko, HIKAGE Takashi, NOJIMA Toshio
    IEICE technical report. Electromagnetic compatibility  2007/11 
    The purpose of this study is to estimate the Electromagnetic field (EMF) distributions emitted by cellular radios in environments surrounded by conductive surfaces, e.g., train carriages or elevators. In this paper, we discuss the effect of a passenger's absorption of electromagnetic fields inside the elevator in more detail. We have proposed a numerical estimation method based on the FDTD technique to examine the EMF in actual elevators. Also an electric field histogram estimation method for electric field strength has been developed to deal with the complicated EMF distributions. This mad...
  • FDTD analysis of medical device interference due to near field generated around HF RFID reader/writers : Construction of numerical model and estimation of induced voltage  [Not invited]
    TOYAMA Norihiro, FUTATSUMORI Shunichi, HIKAGE Takashi, NOJIMA Toshio, KOIKE Ben, FUJIMOTO Hiroshi, TOYOSHIMA Takeshi
    IEICE technical report. Electromagnetic compatibility  2007/11 
    Electromagnetic interference (EMI) from Radio Frequency Identification (RFID) reader/writers on implantable medical devices are investigated and ways to prevent this EMI are discussed. Accordingly, our research objectives are to study a numerical EMI estimation method. First, high frequency (HF) RFID reader/writer antenna models are constructed, and the obtained data of magnetic field distributions created around the antenna by using finite-difference time-domain (FDTD) method and experimentally measured data by using the three-dimensional automatic EMF measurement system are comparatively ...
  • An experimental investigation on typical low frequency amplifiers nonlinear response to microwave/quasi-millimeter wave interference  [Not invited]
    SEO Hiroki, FUTATSUMORI Shunichi, HIKAGE Takashi, NOJIMA Toshio
    IEICE technical report. Electromagnetic compatibility  2007/11 
    Electromagnetic interference (EMI) due to microwave/quasi-millimeter waveband radio waves on low-frequency electronic equipments is mainly caused by nonlinear characteristics of their internal circuits. This is because the envelope of high-frequency signal is detected by the nonlinear response of circuit elements. In this report, to investigate characteristics of interference signal generated by the nonlinear response, interference signal levels depending on frequencies and field strengths of exposure signals are experimentally obtained. Firstly, six types of low frequency basic amplifiers ...
  • C-2-69 Experimental estimations of a 5 GHz High-Temperature Superconducting reaction-type transmitting filter  [Not invited]
    FUTATSUMORI Shunichi, HIKAGE Takashi, NOJIMA Toshio, AKASEGAWA Akihiko, NAKANISHI Teru, YAMANAKA Kazunori
    Proceedings of the Society Conference of IEICE  2007/08
  • B-1-1 A Study on Cross Polarization Characteristics of Incident Waves  [Not invited]
    HASEGAWA Tomotsugu, IWAMOTO Yoshinori, OMIYA Manabu, HIKAGE Takashi
    Proceedings of the Society Conference of IEICE  2007/08
  • A Study on Numerical Vehicle Models for Estimating Antenna Radiation Patterns  [Not invited]
    SHOJI Tomohito, MURAMOTO Mitsuru, HIKAGE Takashi, OMIYA Manabu
    IEICE technical report. Antennas and propagation  2007/07 
    This study is basic research for analysis of a vehicle mounted antenna considering a vehicle body for digital terrestrial television, First we compare analysis with experimental results, and evaluate adequacy of analysis. Next we examine influence on radiation patterns by the difference of the body model.
  • EMCテクノロジー RFIDシステムの医療機器への干渉  [Not invited]
    立石 俊三, 日景 隆
    EMC  2007/06
  • Wide dynamic range nonlinear distortion measurement of High-Temperature Superconducting microwave devices  [Not invited]
    FURUNO Masato, FUTATSUMORI Shunichi, MATSUBARA Hiroshi, HIKAGE Takashi, NOJIMA Toshio, AKASEGAWA Akihiko, NAKANISHI Teru, YAMANAKA Kazunori
    IEICE technical report. Microwaves  2007/04 
    Measurement and analytical methods for nonlinear characteristics of HTS microwave devices are investigated. Firstly, complex power series are introduced to represent the nonlinear characteristics of the devises. Secondly, a wide dynamic range and precise measurement system to obtain the level of the intermodulation distortion are explained. By using the constructed system, a maximum dynamic range of 120 dB and a maximum sensitivity of -100 dBm are achieved. Then, phase components of the nonlinear distortions are calculated from the continuous wave response. Finally, the applicability of com...
  • A 5GHz High-Temperature Superconducting reaction-type transmitting filter to suppress adjacent noises  [Not invited]
    FUTATSUMORI Shunichi, HIKAGE Takashi, NOJIMA Toshio, AKASEGAWA Akihiko, NAKANISHI Teru, YAMANAKA Kazunori
    IEICE technical report. Microwaves  2007/04 
    A 5GHz High-Temperature Superconducting reaction-type transmitting filter (HTS-RTF) to suppress adjacent channel noise is newly proposed. Since reaction-type resonators do not resonate with high-power fundamental signals, an HTS-RTF enables both high-power handling capability and sharp cutoff characteristics compared to existing planar-type HTS transmitting filters. For practical applications in a 5 GHz band, however, it is required for resonators to achieve high-unloaded Q-factors and low radiations as well as low surface current densities in passband. Firstly, novel split open-ring resona...
  • C-2-44 Nonlinear distortion measurements of High-Temperature Superconducting reaction-type resonators for transmitting filters  [Not invited]
    FUTATSUMORI Shunichi, HIKAGE Takashi, NOJIMA Toshio, AKASEGAWA Akihiko, NAKANISHI Teru, YAMANAKA Kazunori
    Proceedings of the IEICE General Conference  2007/03
  • B-1-7 Numerical Analysis of Incident Plane Wave Propagation in a Room with a Set of Furniture  [Not invited]
    Hasegawa Tomotsugu, Iwamoto Yoshinori, Omiya Manabu, Hikage Takashi
    Proceedings of the IEICE General Conference  2007/03
  • B-4-13 Complex permittivity of lightweight solid phantom using carbon nanotube composite  [Not invited]
    Hikage Takashi, Sakaguchi Yuki, Nojima Toshio, Koyamashita Yuji
    Proceedings of the IEICE General Conference  2007/03
  • Numerical analysis for estimation of implantable medical devices EMI caused by RFID reader/writers  [Not invited]
    KONO Taichi, FUTATSUMORI Shunichi, HIKAGE Takashi, NOJIMA Toshio, KOIKE Ben, FUJIMOTO Hiroshi, TOYOSHIMA Takeshi
    IEICE technical report. Electromagnetic compatibility  2007/01 
    Radio Frequency Identification (RFID) systems have been attracting wide interest as essential devices for creating an IT oriented future society and they are expected to achieve various applications. Electromagnetic interference (EMI) from RFID reader/writers on implantable medical device is investigated and ways to prevent this EMI are discussed. Accordingly, our research objectives are to study a numerical EMI estimation method and to reflect this method to the development of new RFID systems that have better performance regarding the RFID/IMD-EMI. Firstly, a lot of EMI experiments using ...
  • Research and development of lightweight solid human phantom model using Silicone Rubber  [Not invited]
    HIKAGE Takashi, SAKAGUCHI Yuki, NOJIMA Toshio, KOYAMASHITA Yuji
    IEICE technical report. Electromagnetic compatibility  2007/01 
    A lightweight human phantom material that has a specific gravity below 1.0 is newly developed and a full sized realistic shaped human phantom model is constructed using this material. Fundamental material composites are carbon nanotube and silicone rubber. The carbon nanotube enables this material to simulate various biological tissues with less specific gravity values than those of original ones. In addition, using the silicone rubber allows us to construct phantom models of various shapes. This paper describes the design principle and estimates the relation between complex permittivity an...
  • HTS Reaction-Type Transmitting Filter Based Upon Split Open-Ring Resonators with Surface Current Density Reduction Technique  [Not invited]
    Shunichi Futastumori, Takashi Hikage, Toshio Nojima, Akihiko Akasegawa, Teru Nakanishi, Kazunori Yamanaka
    2007 ASIA PACIFIC MICROWAVE CONFERENCE, VOLS 1-5  2007  IEEE
     
    An High-Temperature Superconducting reaction-type transmitting filter (HTS-RTF) based upon split open-ring resonators with novel surface current density reduction technique is proposed. Since reaction-type resonators do not resonate with high-power fundamental signals, an HTS-RTF enables both high-power handling capability and steep skirt property compared to existing planar-type HTS transmitting filters. However, fundamental signals in the passband induce a current in their resonators. Firstly, to reduce induced currents in the passband, novel split open-ring resonator (SORR) structures that reduce maximum current densities while offering both high-unloaded Q-factors and low radiations are numerically investigated for 5-GHz band operation. Secondly, to further improve the current density dispersion effect, additional slits are introduced to the resonator surface. Then, to validate the analysis results, fabrications and measurements of the resonators are carried out. Measurements confirm an unloaded Q-factor of 68,000 and third intermodulation-distortion of -82 dBc at 30 dBm input power. Finally, design and fabrication of a 5-GHz three-pole reaction-type filter with bandwidth of 1.5 MHz (FBW = 0.03 %) is conducted. The measurement results confirm the fundamental performance of the filter.
  • RFIDシステムの医療機器への干渉  [Not invited]
    立石俊三, 日景 隆
    電磁環境工学情報EMC(月刊EMC)  2007
  • High-temperature superconducting reaction-type transmitting filter consisting of novel split open-ring resonators  [Not invited]
    Shunichi Futatsumori, Takashi Hikage, Toshio Nojima
    Asia-Pacific Microwave Conference Proceedings, APMC  2006/12 
    High-temperature superconducting (HTS) reaction-type transmitting filter consisting of novel split open-ring resonators is presented. First, it is explained that reaction-type filters are suitable for high power transmission. Secondly, novel split openring resonators, which reduce the maximum current density while maintaining high Q-factors are proposed. Current density dispersion effects are evaluated under the same coupling coefficient. Finally, a three-pole reaction-type filter using split open-ring resonators is designed. The frequency characteristics and current distributions of the filter are investigated by the method of moments. The results predict that the filter realizes both a higher power-handling capability than transmission-type filters and a better skirt property than existing HTS dual-mode filters. Copyright 2006 IEICE.
  • C-2-63 S-parameters estimation of 5GHz superconducting reaction-type transmitting filter using split openring resonators  [Not invited]
    FUTATSUMORI Shunichi, HIKAGE Takashi, NOJIMA Toshio, KURIHARA Kazuaki, YAMANAKA Kazunori
    Proceedings of the Society Conference of IEICE  2006/09
  • B-1-47 Indoor Propagation of Incident Plane Waves by Numerical Analysis  [Not invited]
    Iwamoto Yoshinori, Hasegawa Tomotsugu, Omiya Manabu, Hikage Takashi
    Proceedings of the Society Conference of IEICE  2006/09
  • B-1-48 Highly Precise Analysis of Electromagnetic Field Distributions in a Route Bus  [Not invited]
    Hasegawa Tomotsugu, Omiya Manabu, Hikage Takashi
    Proceedings of the Society Conference of IEICE  2006/09
  • Experimental Investigations on the Biological Free Radical Production in Human Blood Cells due to Microwave Exposure  [Not invited]
    ENDO Masataka, MANABE Takeaki, HIKAGE Takashi, NOJIMA Toshio
    IEICE technical report. Electromagnetic compatibility  2006/08 
    The purpose of this study is to investigate the effects of microwave exposure on biological free radical production, focusing especially on mobile radio frequencies. In vitro experiments for the hydroxyl radical production on human white blood cells after exposure to modulated or non-modulated 900 MHz and 2.45 GHz microwave were performed. Then, the thermostatic device is adopted to maintain the temperature of the sample at less than 39 degrees Celsius. The exposure experiments were carried out by using about six hundred tissues, and the free radical production was estimated with the fluore...
  • Fundamental Studies on Indoor Propagation of Broadcasting Radio  [Not invited]
    IWAMOTO Yoshinori, HASEGAWA Tomotsugu, OMIYA Manabu, HIKAGE Takashi
    ITE technical report  2006/07
  • Highly Precise Analysis of Electromagnetic Field Distribution Caused by Cell Phone Terminals in a Route Bus  [Not invited]
    HASEGAWA Tomotsugu, OMIYA Manabu, HIKAGE Takashi
    ITE technical report  2006/07
  • Experimental electromagnetic interference estimations for implantable medical devices from RFID reader/writer to develop a numerical analysis method  [Not invited]
    FUTATSUMORI Shunichi, ENDO Masataka, TAGUCHI Shunsuke, HIKAGE Takashi, NOJIMA Toshio, KOIKE Ben, FUJIMOTO Hiroshi, TOYOSHIMA Takeshi
    IEICE technical report. Electromagnetic compatibility  2006/06 
    Radio Frequency Identification (RFID) systems have been attracting wide interest as essential devices for constructing IT oriented future society and it is expected to achieve various applications. Electromagnetic interference (EMI) from RFID reader/writer on medical devices is investigated and preventions of the EMI are currently discussed. Moreover, it is required to more detailed investigations such as effects of human body and other lossy materials existing at actual environments. In addition, errors of experimental test systems should be precisely analyzed. The purpose of this research...
  • Numerical analysis of the current density distributions and frequency responses in the High-Temperature Superconductor split open-ring resonators  [Not invited]
    FUTATSUMORI Shunichi, HIKAGE Takashi, NOJIMA Toshio
    IEICE technical report. Microwaves  2006/04 
    In general, the microwave thin film filters employing superconducting materials enable extremely high Q performance with small sized planer structure circuit construction in comparison with existing room temperature devices. One of the most important technical issues is to achieve high power handling capability. In order to develop High-Temperature Superconductor (HTS) filters for transmitters, reaction type filters, which do not resonate by high-power fundamental signals, are proposed. In addition, novel resonator structures consisting of the split type open-ring resonator are proposed. Sp...
  • B-4-17 Experimental test system to estimate the EMI from RFID reader/writer on implantable cardiac pacemaker  [Not invited]
    FUTATSUMORI Shunichi, HIKAGE Takashi, NOJIMA Toshio, KOIKE Ben, Fujimoto Hiroshi, TOYOSHIMA Takeshi
    Proceedings of the IEICE General Conference  2006/03
  • C-2-38 Numerical analysis of the current density distribution in the High-Temperature Superconductor split open-ring resonator  [Not invited]
    FUTATSUMORI Shunichi, HIKAGE Takashi, NOJIMA Toshio
    Proceedings of the IEICE General Conference  2006/03
  • A precise electromagnetic field estimation in elevators considering implantable cardiac pacemaker EMI from cellular radios  [Not invited]
    Louis Ray Harris, Takashi Hikage, Toshio Nojima, Manabu Omiya, Ally Simba, Soichi Watanabe, Takashi Shinozuka
    Progress in Electromagnetics Research Symposium  2006/01 
    The purpose of this study was to estimate the Electromagnetic Field (EMF) distributions in environments surrounded by conductive surfaces, e.g. train carriages or elevators. Analysis of the results would then enable us to determine possible effects of EMI on Implantable Cardiac Pacemakers in these kinds of environment, commonly referred to as a semi-echoic environments (SEE).
  • Experimental test system to assess the EMI from RFID reader/writer on implantable cardiac pacemaker  [Not invited]
    Shunichi Futatsumori, Taichi Kono, Takashi Hikage, Toshio Nojima, Ben Koike
    Progress in Electromagnetics Research Symposium  2006/01 
    In this paper, a newly developed experimental test system for electromagnetic interference (EMI) due to Radio Frequency Identification (RFID) reader/writers on medical devices is introduced and the basic design concept is discussed. The aim of this research is to establish an EMI estimation method using FDTD analysis and a measurement system to obtain precise and detailed EMI characteristics regarding RFID EMI on medical devices. Practical situations of EMI due to existing RFID reader/writers on medical devices is investigated and ways to prevent this EMI are currently discussed by some organizations. In addition, more detailed investigations need to be carried out such as the effects of the three-dimensional electromagnetic fields (EMF) containing human body of actual environments. Furthermore, it is required to design an experiment system with minimum measurement errors. The EMI test experiments on 13 types of implantable pacemakers and defibrillators were carried out to validate the fundamental performance of the test system.
  • Estimation of the EMF excitation by cellular radios in actual train carriages - With and without passenger  [Not invited]
    Takashi Hikage, Yusuke Abiko, Masahiko Hirono, Toshio Nojima, Manabu Omiya, Soichi Watanabe, Takashi Shinozuka
    IEEE International Symposium on Electromagnetic Compatibility  2005/12 
    Precise computer simulations using 800 MHz and 2 GHz transmitters in an actual train carriage are conducted on the electromagnetic field (EMF) distributions excited inside train carriages. With regard to the EMC of the portable radio terminals such as cellular phones and data communication transceivers that transmit RF waves, one of the most important and substantial issues is to prevent the occurrence of unwanted effects on the human health due to the RF exposure from such radio devices [1], [2], Since the portable radios may be used in various environments, accurate and reliable estimations of EMC in practical environments are required. However, the measurements in the actual environment need enormous costs and it is also difficult to carry out precisely. In this paper, we carry out the precise numerical simulations to examine the EMF actual environment. A simplified histogram estimation method for electric field strength is developed to deal with the complicated EMF distributions. Typical results of FDTD analysis and actual measurement data are then shown. Finally, considerations and conclusions are made. ? 2005 IEEE.
  • FUTATSUMORI Shunichi, HIKAGE Takashi, NOJIMA Toshio
    IEICE technical report. Microwaves  2005/09  The Institute of Electronics, Information and Communication Engineers
     
    HTS (High-Temperature Superconductor) microwave devices applied to transmission systems have problems in terms of their power handling capability caused by surface-current concentrations on the devices. Although low power applications such as receiving filters for mobile base stations are researched and developed, HTS filters aimed at transmitters do not have same the performance as receiving filters. Reaction type filters, which do not resonate by high-power fundamental signals, are proposed. The most serious problem of the filter is currents induced on HTS resonators by fundamental signals. Some amount of the current exceeds HTS critical current density. In this report, new resonator structures consisting of the split type open-ring resonator are proposed and confirm the effect of maximum current density reduction using full-wave EM simulators. Furthermore, fundamental circuit design and feasibility of the filter are discussed.
  • B-1-126 Analysis of Meander Line Antenna with Ground plane  [Not invited]
    KONO Taichi, KAWAHARA Yusuke, HIKAGE Takashi, NOJIMA Toshio
    Proceedings of the Society Conference of IEICE  2005/09
  • B-4-9 FDTD Analysis for Propagation Characteristics of Wireless LAN equipped in a Jumbo Jet  [Not invited]
    KAWAHARA Yusuke, KONO Taichi, SUMI Yuki, HIKAGE Takashi, NOJIMA Toshio, OMIYA Manabu
    Proceedings of the Society Conference of IEICE  2005/09
  • C-1-6 Considerations on Distributions of Electromagnetic Field Due to a Cell Phone in a City Bus  [Not invited]
    HASEGAWA Tomotsugu, OMIYA Manabu, HIKAGE Takashi
    Proceedings of the Society Conference of IEICE  2005/09
  • C-2-63 Power handling capability improvement of the microwave High-Temperature Superconductor Reaction filter  [Not invited]
    FUTATSUMORI Shunichi, HIKAGE Takashi, NOJIMA Toshio
    Proceedings of the Society Conference of IEICE  2005/09
  • Fundamental circuit construction and CAD simulation of superconducting reaction type transmitting filter aiming at mobile base station application  [Not invited]
    FUTATSUMORI Shunichi, HIKAGE Takashi, NOJIMA Toshio
    IEICE technical report. Microwaves  2005/09 
    HTS (High-Temperature Superconductor) microwave devices applied to transmission systems have problems in terms of their power handling capability caused by surface-current concentrations on the devices. Although low power applications such as receiving filters for mobile base stations are researched and developed, HTS filters aimed at transmitters do not have same the performance as receiving filters. Reaction type filters, which do not resonate by high-power fundamental signals, are proposed. The most serious problem of the filter is currents induced on HTS resonators by fundamental signal...
  • 大規模数値シミュレーションによる電車内電磁界応答および分布推定  [Not invited]
    長谷川 公嗣, 大宮 学, 日景 隆
    映像情報メディア学会技術報告  2005/07
  • Microwave Exposure Effects on the Production of Free Radicals in Cultured Human Fibroblasts  [Not invited]
    MANABE Takeaki, HIKAGE Takashi, NOJIMA Toshio
    IEICE technical report. Electromagnetic compatibility  2005/06 
    Some experiments are made in order to research for microwave exposure effects on the productions of free radicals in cultured human skin fibroblasts. The fibroblasts are irradiated with the microwave at the frequency of 2.45GHz continuous wave (CW) or high-duty cycle pulse modulated wave. And the free radicals are measured by using fluorescence microscopy or Electron-Spin-resonance (ESR) spectroscopy.
  • EMF Analysis of semi-echoic environment models using the parallel FDTD method : analytical models of a train carriage and an airplane  [Not invited]
    KAWAHARA Yusuke, KONO Taichi, SUMI Yuki, HIKAGE Takashi, NOJIMA Toshio, OMIYA Manabu
    IEICE technical report. Electromagnetic compatibility  2005/06 
    The precise and large-scale numerical simulations are carried out to examine the electromagnetic field (EMF) in this paper. The FDTD technique and a supercomputer are employed to estimate the EMF distributions excited in the semi-echoic environments such like a train carriage or an airplane inside. Moreover, large-scale parallel computing based upon several node partitions is used because of its memory and speed capabilities. It gives us a good perspective within a reasonable computation time. In addition, a simple histogram estimation method for electric field strength in whole area of the...
  • A Precise Study on Electromagnetic Fields in the Semi-Echoic Environment  [Not invited]
    SUMI Yuki, HIKAGE Takashi, NOJIMA Toshio, OMIYA Manabu, WATANABE Soichi, SHINOZUKA Takashi
    IEICE technical report. Electromagnetic compatibility  2005/06 
    The EMF distributions excited in the actual train carriage are precisely estimated by using a large-scale parallel FDTD technique. Moreover, it is assume in the analysis that the inner surface of train carriage body is covered by two kinds of non-metallic material or perfectly conductive walls and train carriage contains many human bodies and cellular radios. In addition, a simple histogram estimation method for electric field strength in whole area of the train carriage is employed in order to deal with the complicated electromagnetic field distributions.
  • B-4-4 FDTD analysis of RF propagations in a semi-echoic environment  [Not invited]
    HIKAGE Takashi, SUMI Yuki, NOJIMA Toshio, OMIYA Manabu
    Proceedings of the IEICE General Conference  2005/03
  • C-2-91 An investigation for the microwave High-Temperature Superconductor reaction filter  [Not invited]
    Futatsumori Shunichi, Hikage Takashi, Nojima Toshio
    Proceedings of the IEICE General Conference  2005/03
  • Numerical Analysis of Electromagnetic Fields in a Train Carriage  [Not invited]
    OMIYA Manabu, HIKAGE Takashi
    ITE technical report  2004/07
  • A Study on Parallel FDTD Analysis of the Electromagnetic Fields in the Semi-Echoic Environment  [Not invited]
    SUMI Yuki, HIKAGE Takashi, NOJIMA Toshio, OMIYA Manabu, WATANABE Soichi, SHINOZUKA Takashi
    IEICE technical report. Electromagnetic compatibility  2004/06 
    The precise numerical simulations to examine the EMF of large-scale geometry are carried out in this paper. The FDTD technique and a supercomputer are employed to estimate the EMF distributions excited in the semi-echoic environments such like a car or train carriage inside. Moreover, large-scale parallel computing based upon several node partitions is used because of its memory and speed capabilities. It gives us good perspective within a reasonable computation time.
  • 2.45GHz Experimental system design and preliminary experiments for the microwave exposure effects on the biological Free-Radical excitation  [Not invited]
    MANABE Takeaki, HIKAGE Takashi, NOJIMA Toshio
    IEICE technical report. Electromagnetic compatibility  2004/06 
    The fundamental experiment is carried out in order to investigate the effect of the microwave exposure on the biological free-radical production. For this purpose, high intensity exposure system, which consists of high power magnetron, dielectric lenses and a horn antenna, is newly developed. By using this beam-forming equipment, an effective EMF concentration on the target issue can be achieved. Some kinds of dead tissues are irradiated with the microwave at the frequency of 2.45GHz continuous wave (CW).
  • B-4-4 Preliminary Experiments about the microwave exposure effect on the biological Free-Radical excitation  [Not invited]
    MANABE Takeaki, HIKAGE Takashi, NOJIMA Toshio
    Proceedings of the IEICE General Conference  2004/03
  • A STUDY ON IMPLANTABLE CARDIAC PACE MAKER EMI FROM CELLULAR RADIOS IN SEMI-ECHOIC ENVIRONMENTS - FDTD Analysis and Experiments in Actual Train Carriage -"  [Not invited]
    2004 International Symposium on Electromagnetic Compatibility  2004
  • ESTIMATION OF THE EMF IN ACTUAL TRAIN CARRIAGE USING THE PARALLEL FDTD METHODS  [Not invited]
    International Conference of Antennas and Propagation (ISAP) 2004  2004
  • Microwave Exposure Effects on the Biological Free Radical Production -2.45GHz exposure system design and estimation with ESR -  [Not invited]
    BIOLOGICAL EFFECTS of EMFs 3rd International Workshop  2004
  • Large-Scale Numerical Analysis of the EMF in Actual Train Carriages  [Not invited]
    2004 Korea-Japan Joint Conference on AP/EMC/EMT (KJJC-AP/EMC/EMT 2004)  2004
  • Design of Slot Antennas and Arrays Using the FDTD Technique and a Parallel Supercomputer  [Not invited]
    Manabu Omiya, Kosuke Munakata, Takashi Hikage
    Annual Review of Progress in Applied Computational Electromagnetics  2003/12 
    The cavity-backed slot antenna is used as an element for the solar power satellite SPS2000. The antenna element has advantages over other types of antenna in mechanical strength, heat dissipation and a low profile structure. The authors have already proposed the cavity-backed slot antenna whose sidewalls consist of conductive posts. In this paper, we propose design methods of cavity-backed slot antenna with the posts excited by a short-ended probe or an inverted-F element. Then, antenna parameters providing good impedance matching are derived. The effectiveness of the design method and antenna parameters is verified by experiments. Moreover, quantities of mutual coupling in large-scale antenna arrays will be computed by using the supercomputer.
  • Circular Polarized Array antenna using Cavity-Backed Slot Antenna for Microwave Energy Transmission at 5.8 GHz  [Not invited]
    HIKAGE Takashi, IZAWA Yoshinori, NOJIMA Toshio, OMIYA Manabu, ITOH Kiyohiko
    Proceedings of the Society Conference of IEICE  2003/09
  • Post-Wall Cavity-Backed Slot Antennas for Spacetenna of Space Solar Power Satellite  [Not invited]
    OMIYA Manabu, MUNAKATA Kosuke, HIKAGE Takashi
    ITE technical report  2003/07
  • Cavity-Backed Slot Antenna Array for Circular Polarization  [Not invited]
    IZAWA Yoshinori, HIKAGE Takashi, NOJIMA Toshio, OMIYA Manabu, ITOH Kiyohiko
    Technical report of IEICE. OPE  2003/07 
    The purpose of this paper is to investigate feasibility to use cavity-backed slot antenna elements as antenna element for circular polarized antenna array operating at the frequency of 5.8 GHz. They are used as an element of the microwave energy transmission antenna system in the space solar power satellite (SSPS) recently discussed in Japan. Our previous works were related to the antenna parameters of the elements operating at the frequency of 5.8 GHz. First we determine geometries and dimension of the antenna satisfying the system demands. Next we propose cavity-backed slot antenna elemen...
  • Circular Microstrip Patch Antenna with Slits Suppressing Higher Harmonics  [Not invited]
    NAGAE Tomoko, HIKAGE Takashi, NOJIMA Toshio, OMIYA Manabu, ITOH Kiyohiko
    IEICE technical report. Electromagnetic compatibility  2003/07 
    A circular microstrip patch antenna (CMSA) is mainly used in the microwave power transmission system. For 2.45GHz band Solar Power Satellite (SPS), we proposed some types of antenna with slits to suppress re-radiation at higher harmonic frequencies. In this paper, we develop the CMSA with slits for Space Solar Power Satellite (SSPS) operating at the frequency of 5.8GHz, in which slits are located along surface current streams related to the dominant TM_<110>mode in order to suppress higher harmonics without disturbing a resonance of the dominant mode. The relations between slit parameters a...
  • A Study on Mutual Coupling in Cavity-Backed Slot Antenna Array Consisting of Parallel Plates and Posts which is Excited by an Inverted-F Element  [Not invited]
    HIKAGE Takashi, MUNAKATA Kosuke, NOJIMA Toshio, OMIYA Manabu, ITOH Kiyohiko
    Proceedings of the IEICE General Conference  2003/03
  • FDTD Analysis and Design of Slot Antenna and Array for Microwave Energy Transmission  [Not invited]
    Proceedings of 2003 Asia-Pacific Microwave Conference  2003
  • Cavity-Backed Slot Antennas with Sidewalls Consisting of Posts and Feeder of an Inverted-F Element for Wireless Energy Transmission  [Not invited]
    MUNAKATA Kosuke, HIKAGE Takashi, OMIYA Manabu
    ITE Technical Report  2002/07 
    The cavity-backed slot antenna is used as an element for the solar power satellite SPS2000. The antenna element is superior to others in mechanical strength and heat dissipation, and it tends to be a low profile structure. The authors have already proposed the cavity-backed slot antenna whose sidewalls consist of conductive posts. In this paper, we propose design methods of cavity-backed slot antenna with the posts, which are fed by an inverted-F element. Then, antenna parameters realizing the good impedance matching at the frequency of 2.45 GHz are derived. The effectiveness of the design ...
  • Design of Cavity-Backed Slot Antenna for Microwave Energy Transmission at the Frequency of 5.8 GHz  [Not invited]
    IZAWA Yoshinori, HIKAGE Takashi, NOJIMA Toshio, OMIYA Manabu, ITOH Kiyohiko
    IEICE technical report. Antennas and propagation  2002/07 
    The purpose of this paper is to investigate cavity-backed slot antenna elements operating at the frequency of 5.8GHz. They are used as an element of the microwave energy transmission antenna system in the space solar power satellite(SSPS) recently discussed in Japan. Our previous works were related to the antenna elements operating at the frequency of 2.45 GHz. First we determine geometries and dimension of the antenna element satisfying the system demands. Then we propose two types of cavity-backed slot antenna element. The antenna parameters realizing the impedance matching are presented....
  • Development of Cavity-Backed Slot Antenna for Spacetenna of Space Solar Power Satellite at the Frequency of 5.8 GHz  [Not invited]
    Proceedings of 2002 Asia-Pacific Microwave Conference (APMC2002  2002
  • FDTD Analysis and Design of Cavity-Backed Slot Antennas for Microwave Energy Transmission  [Not invited]
    The 18th Annual Review of Progress in Applied Computational Electromagnetics  2002
  • Slot antenna consisted of two conductive plates and thin wires  [Not invited]
    M. Omiya, T. Hikage, K. Murakami, K. Itoh
    IEEE Antennas and Propagation Society, AP-S International Symposium (Digest)  2001/11 
    A design method of antenna elements whose conductive sidewalls in the conventional model were replaced by thin wires was discussed. Array antennas and low profile antenna elements were easy to be produced by this configuration. A clarification of the relations between wire intervals and input characteristics was presented. This method was available to design a new type of antenna element.
  • Slot Antenna Consisting of Two Parallel Conductive Plates and Cylindrical Posts  [Not invited]
    Hikage Takashi, Murakami Kazuyuki, Omiya Manabu, Itoh Kiyohiko
    Proceedings of the Society Conference of IEICE  2001/08
  • Design of Cavity-Backed Slot Antenna with Sidewalls Replaced by Posts Taking Account of Mutual Coupling  [Not invited]
    MURAKAMI Kazuyuki, HIKAGE Takashi, OMIYA Manabu, ITOH Kiyohiko
    IEICE technical report. Antennas and propagation  2001/07 
    The cavity-backed slot antenna is used as an element for the solar power satellite SPS2000. The antenna element is superior to others in mechanical strength and heat dissipation, and is capable of low profile cavity structures. Authors have already proposed a new type of cavity-backed slot-antenna whose sidewalls are replaced by posts for the purpose of easy production of antenna array. In this paper, we discuss design methods of antenna elements when mutual coupling among antenna elements is taken into account. Moreover, relations between the post intervals and the amount of mutual couplin...
  • Comparison of analysis methods for performance of cavity-backed slot antennas using the FDTD technique  [Not invited]
    Takashi Hikage, Manabu Omiya, Kiyohiko Itoh
    Electronics and Communications in Japan, Part I: Communications (English translation of Denshi Tsushin Gakkai Ronbunshi)  2001/07 
    By applying the FDTD method to the evaluation of the characteristics of a cavity-backed slot antenna, a design considering the feed structure is possible. In this paper, a feed model suitable for the design and analysis of a cavity-backed slot antenna is presented. As feed models, a gap voltage model and a coaxial model are used and results of their analysis are compared. From the analysis of the input characteristics, it is revealed that characteristic evaluation is possible in the coaxial model with fewer time steps than the gap voltage model. In the evaluation of the radiation characteristics, the absolute gain evaluation method is presented with a sinusoidal excitation. From the results of analysis of the absolute gain, the results converge within about 15 periods in the case of the coaxial model. The obtained radiation characteristics agree with the experimental results. In the gap voltage model, undulations of the absolute gain values are observed. From a comparison of these characteristic evaluations, the coaxial model is found to be suitable for FDTD analysis of a cavity-backed slot antenna.
  • Cavity-Backed Slot Antenna with Sidewalls Consisted of Thin Wires for Microwave Energy Transmission  [Not invited]
    HIKAGE Takashi, MURAKAMI Kazuyuki, OMIYA Manabu, ITOH Kiyohiko
    Proceedings of the IEICE General Conference  2001/03
  • Cavity-Backed Slot Antenna with Sidewalls Consisting of Thin Wires  [Not invited]
    Proceedings of Progress In Electromagnetics Research Symposium (PIERS 2001)  2001
  • Performance evaluation of cavity-backed slot antennas using the FDTD technique  [Not invited]
    Takashi Hikage, Manabu Omiya, Kiyohiko Itoh
    IEEE Antennas and Propagation Society, AP-S International Symposium (Digest)  2000/12 
    Two feed models, a gap voltage model and a coaxial model are compared to demonstrate their suitability for the estimation of input characteristics. Based on this, an evaluation method giving accurate input characteristics with smaller amount of time steps needed to be developed is derived.
  • Design of Cavity-Backed Slot Antennas excited by a Loop Element  [Not invited]
    HIKAGE Takashi, IMADA Mizuki, OMIYA Manabu, ITOH Kiyohiko
    Proceedings of the Society Conference of IEICE  2000/09
  • Comparison of FDTD Analysis Methods for Mutual Coupling of Array Antennas  [Not invited]
    MURAKAMI Kazuyuki, HIKAGE Takashi, OMIYA Manabu, ITOH Kiyohiko
    Technical report of IEICE. SAT  2000/07 
    The cavity-backed slot antenna is used as an element for the spacetenna of the solar power satellite SPS2000. The spacetenna is a huge phased array antenna somposed of 2.5 million antenna elements. Therefore, it should be noted that the mutual coupling between elements affects the beam scanning seriously. The paper discusses the evaluation method of mutual coupling using the finite-difference time-domain(FDTD)technique collaborating with the second-order absorbing boundary condition(ABC)or the PML ABC. It is found from computations on E-plane two-and four-element array antennas that the FDT...
  • A・P2000-39 / SAT2000-30 / MW2000-39 Comparison of FDTD Analysis Methods for Mutual Coupling of Array Antennas  [Not invited]
    MURAKAMI Kazuyuki, HIKAGE Takashi, OMIYA Manabu, ITOH Kiyohiko
    IEICE technical report. Antennas and propagation  2000/07 
    The cavity-backed slot antenna is used as an element for the spacetenna of the solar power satellite SPS2000. The spacetenna is a huge phased array antenna composed of 2.5 million antenna elements. Therefore, it should be noted that the mutual coupling between elements affects the beam scanning seriously. The paper discusses the evaluation method of mutual coupling using the finite-defference time-domain(FDTD)technique collaborating with the second-order absorbing boundary condition(ABC)or the PML ABC. It is found from computations on E-plane two- and four-element array antennas that the FD...
  • Evaluation of Mutual Coupling of Low-Profile Cavity-Backed Slot Antennas  [Not invited]
    HIKAGE Takashi, MURAKAMI Kazuyuki, OMIYA Manabu, ITOH Kiyohiko
    Proceedings of the IEICE General Conference  2000/03
  • Considerations on Cavity-Backed Slot Antennas with Side Walls Composed of Wires  [Not invited]
    2000
  • Finite-Difference Time-Domain Analysis of Mutual Couplings of Cavity-Backed Slot Antennas Using Super-Computer System SR8000  [Not invited]
    2000
  • Low Profile Cavity-Backed Slot Antennas for Microwave Energy Transmission  [Not invited]
    Proceedings of the 2000 International Symposium on Antennas and Propagation  2000
  • アレーアンテナ素子間相互結合のFDTD解析法に関する比較検討  [Not invited]
    電子情報通信学会 アンテナ・伝播,衛星通信,マイクロ波研究会  2000
  • スーパーコンピュータSR8000を用いた時間領域差分法によるキャビティ付スロットアンテナの素子間相互結合評価  [Not invited]
    北海道大学大型計算機センターニュース  2000
  • 側面をワイヤで構成したキャビティ付スロットアンテナに関する検討  [Not invited]
    第3回宇宙太陽発電システム(SPS)シンポジウム講演要旨集  2000
  • Design of a Low-Profile Cavity-Backed Slot Antenna for Microwave Energy Transmission  [Not invited]
    HIKAGE Takashi, IMADA Mizuki, OMIYA Manabu, ITOH Kiyohiko
    IEICE technical report. Antennas and propagation  1999/12 
    The cavity-backed slot antenna is used as an element for the solar power satellite SPS2000. The antenna element is superior to other elements in mechanical strength and heat dissipation, and has prospects of low profile cavity structure. In this paper we explain the detail of the design method realizing a low profile element which the authors had proposed in the previous study, and clarify the fundamental rule of impedance matching using equivalent circuit models. Upon showing design results for the elements with the cavity heights of 2 mm and 1 mm, and comparing them with measurements, we ...
  • Considerations on Evaluation of Mutual Coupling of Cavity-Backed Slot Antenna Using the FDTD Technique  [Not invited]
    HIKAGE Takashi, OMIYA Manabu, ITOH Kiyohiko
    Proceedings of the Society Conference of IEICE  1999/08
  • Design of Cavity-Backed Slot Antenna with Side Walls of Wire  [Not invited]
    OMIYA Manabu, HIKAGE Takashi, IMADA Mizuki, ITOH Kiyohiko
    Proceedings of the Society Conference of IEICE  1999/08
  • Design Method of Cavity Backed Slot Antenna Realizing Low Profile and Downsized Structure  [Not invited]
    HIKAGE Takashi, IMADA Mizuki, OMIYA Manabu, ITOH Kiyohiko
    IEICE technical report. Antennas and propagation  1999/07 
    The cavity-backed slot antenna is used as an element for the solar power satellite SPS2000. The antenna element is superior to other elements in mechanical strength and heat dissipation, and has prospects of low profile cavity structures. In this paper we explain the details of the design method realizing a low profile element which the authors had proposed in the previous study, and clarify the fundamental rule of impedance matching. Moreover, relations between antenna parameters and frequency bandwidth of input characteristic are derived by the analysis. Upon showing design results for th...
  • B-1-92 Design Method of a Low-Profile Cavity-Backed Slot Antenna  [Not invited]
    OMIYA Manabu, HIKAGE Takashi, IMADA Mizuki, ITOH Kiyohiko
    Proceedings of the IEICE General Conference  1999/03
  • Proposal and Analysis of Cavity-Backed Slot Antennas for Microwave Energy Transmission  [Not invited]
    Takashi Hikage, Takashi Hikage, Takashi Hikage, Norio Ohno, Manabu Omiya, Manabu Omiya, Manabu Omiya, Manabu Omiya, Manabu Omiya, Manabu Omiya, Kiyohiko Itoh, Kiyohiko Itoh, Kiyohiko Itoh, Kiyohiko Itoh, Kiyohiko Itoh
    Electronics and Communications in Japan, Part 1  1999/03 
    A cavity-backed slot antenna is thought to be one of the most suitable elements for the wireless transmission of microwave energy, and especially for SPS2000, which was conceptually developed in Japan as a straw-man model of the solar power satellite. First, this paper presents the configuration and dimensions of the antenna element. Second, we propose a feeder geometry for which the above requirements are fulfilled and the desired antenna characteristics are obtained. The feeders are a short-ended probe and an inverted-F element whose dimensional parameters are examined experimentally and analytically. Here we use the FDTD technique developed in our previous study for the analysis of the cavity-backed slot antenna excited by these two kinds of feeder. ? 1998 Scripta Technica.
  • Comparison of Analysis Methods for Performance of Cavity-Backed Slot Antennas Using the FDTD Technique  [Not invited]
    1999
  • Development of Low-Profile Cavity-Backed Slot Antenna for Microwave Energy Transmission  [Not invited]
    1999
  • Design Method of Cavity Backed Slot Antenna Realizing Low Profile and Miniaturized Structure  [Not invited]
    1999
  • Design of Cavity-Backed slot antennas using the finite-difference time-domain technique  [Not invited]
    Manabu Omiya, Takashi Hikage, Norio Ohno, Kenich Horiguchi, Kiyohiko Itoh
    IEEE Trans. Antennas and Propagation  1998/12 
    A cavity-backed slot antenna is thought to be one of the most suitable elements for the wireless transmission of microwave energy. A design technique is developed for the cavitybacked slot antenna using the finite-difference time-domain (FDTD) method. The technique is effective in characterizing antenna performance such as the input impedance and the far-field pattern since it takes into account the geometry of the feeder as well as the cavity. In this paper, we present a method that overcomes difficulties when the FDTD method is used to design the antenna. Moreover, we discuss how to determine the calculation parameters used in the FDTD analysis. Several numerical results are presented, along with measured data, which demonstrate the validity, efficiency, and capability of the techniques. The paper proposes a new prediction method for frequency characteristics of the cavity-backed slot antenna, which applies computational windows to time sequence data. It is emphasized that windowing the slow decaying signal enables the extraction of accurate antenna characteristics. We also discuss how to estimate antenna patterns when we use a sinusoidal voltage excitation. ? 1998 IEEE.
  • FDTD Simulations of Mutual Coupling of an Antenna Array  [Not invited]
    HIKAGE Takashi, OMIYA Manabu, ITOH Kiyohiko
    Proceedings of the Society Conference of IEICE  1998/09
  • Considerations on Design of Low-Profile Cavity-Backed Slot Antennas  [Not invited]
    HIKAGE Takashi, OMIYA Manabu, ITOH Kiyohiko
    IEICE technical report. Microwaves  1998/07 
    We have developed antenna elements for the spacetenna of the solar power satellite in Japan, SPS2000. The cavity-backed slot antenna is used as an element of spacetenna to transmit the microwave power at the frequency of 2.45 GHz. We propose a mthod by which low-profile cavity-backed slot antennas are designed. An impedance mathcing at the frequency of 2.45 GHz is obtained for the proper location of the feeding probe and the slot dimension in the antenna geometry. Furthermore we show antenna parameters which realize the impedance matching. The finite-difference time-domain technique is employed to analyze antenna characteristics. Good agreement between the calculation results and experimental measurements for elements with the cavity of less than 12mm high demonstrates the effectriveness of the proposed design method.
  • FDTD Analysis on Beam Steering Performance of Phased Array Antenna  [Not invited]
    HIKAGE Takashi, OMIYA Manabu, FUKUCHI Hisanao, ITOH Kiyohiko
    Proceedings of the IEICE General Conference  1998/03
  • Proposal of Cavity-Backed Slot Antennas for the Microwave Energy Transmission  [Not invited]
    1998
  • Evaluation of Mutual Coupling of Cavity-Backed Slot Antennas Using the FDTD Technique  [Not invited]
    1998 Asia-Pacific Microwave Conference Proceedings APMC'98  1998
  • FDTD Analysis of Mutual Coupling of Cavity-Backed Slot Antenna Array  [Not invited]
    Takashi Hikage, Manabu Omiya, Kiyohiko Itoh
    IEICE Transactions on Electronics  1998/01 
    This paper discusses a method to evaluate mutual couplings of cavity-backed slot antennas using the FDTD technique. The antenna fed by the short-ended probe is considered, which is investigated as an element of the power transmission antenna, Spacetenna, for the solar power satellite SPS2000. It is found from the FDTD computation on E-plane two- and four-element array antennas that the size of the problem space should be larger for the evaluation of the mutual coupling than for the estimation of the input impedance. Since enlarging the size of the problem space requires a large amount of computer storage, it is not practical for computer simulations. In order to carry out accurate estimations of the mutual coupling with relatively small amount of computer memory, the problem space is extended only in the broadside of the array antenna and in the other directions there are ten cells between the antenna surface and the outer boundary. Computer simulations demonstrate that there are no differences between the results of the proposed problem space geometry and the problem space extended in each direction of the axis coordinate by the same number of cells. Furthermore comparisons of computed and experimental results demonstrate the effectiveness of the approach after discussing how large the size of the problem space is required to estimate the mutual coupling.
  • FDTD Analysis of a Cavity-Backed Slot Antenna  [Not invited]
    OMIYA Manabu, HIKAGE Takashi, ITOH Kiyohiko
    Proceedings of the Society Conference of IEICE  1997/08 
    太陽発電衛星SPS2000では送電アンテナ素子としてキャビティ付スロットアンテナの利用が検討されている. 本研究グループではアンテナ素子の設計にFDTD法を適用することを提案している. 本稿では, 同軸線路を接続したアンテナ素子のFDTD解析結果について議論する.
  • Cavity-Backed Slot Antennas for the Microwave Energy Transmission  [Not invited]
    HIKAGE Takashi, OHNO Norio, OMIYA Manabu, ITOH Kiyohiko
    IEICE technical report. Antennas and propagation  1997/07 
    We have developed antenna elements for the spacetenna of SPS2000. SPS2000 is the nickname of the strawman model of the solar power satellite in Japan. First it is shown that a cavity-backed slot antenna is one of the most suitable antenna elements by showing the configuration of an antenna whose dimension prevents glating lobes in radiation patterns at the beam steering. We also design a cavity-backed slot antenna whose dimensions are defined in the conceptual study of SPS2000. In this paper we propose two kinds of antenna element, which are fed by a shorted probe and an inverted-F type fee...

Industrial Property Rights

Awards & Honors

  • 2023/11 2023 International Conference on Emerging Technologies for Communications Outstanding Contribution Award
     
    受賞者: Takashi Hikage
  • 2022/09 電子情報通信学会 通信ソサイエティ活動功労賞
     ”2016年9月”,”2017年9月”および”2019年9月”同賞受賞 
    受賞者: 日景 隆
  • 2020/11 Faculty of Information Science and Technology, Hokkaido University 令和2年度 若手産学共同研究促進事業 研究院長賞
     
    受賞者: Takashi Hikage
  • 2020/06 電子情報通信学会 論文賞（第76回）
     数値シミュレーションを用いた26 GHz帯屋内伝搬における人体遮蔽特性推定法についての一検討 
    受賞者: 日景 隆
  • 2012/09 EMC Europe 2012 The Best Paper Award
     "Numerical Assessment Methodology for Active Implantable Medical Device EMI due to Magnetic Resonance Wireless Power Transmission Antenna" 
    受賞者: HIKAGE Takashi
  • 2008/12 Asia-Pacific Microwave Conference The APMC PRIZE
     "An Experimental Validation of a Detailed Numerical Model for Predicting Implantable Medical Devices EMI due to Low-band RFID Reader/writers" 
    受賞者: HIKAGE Takashi
  • 2002 IEEE AP-S Japan Chapter Young Engineer Award
     
    受賞者: 日景 隆
  • 2001 電子情報通信学会 学術奨励賞
     
    受賞者: 日景 隆
  • 1999/12 電子情報通信学会 アンテナ・伝播研究専門委員会 1999年度アンテナ・伝播研究会フレッシュマンセッション 優秀賞
     送電アンテナ用薄形キャビティ付きスロットアンテナの設計 
    受賞者: 日景 隆
  • 1999 電子情報通信学会北海道支部 学生員奨励賞
     
    受賞者: 日景 隆
  • 1998 電気関係学会北海道支部連合大会 若手講演者表彰
     
    受賞者: 日景 隆

Research Grants & Projects

  • 日本学術振興会：科学研究費助成事業 基盤研究(C)
    Date (from‐to) : 2022/04 -2025/03 
    Author : 日景 隆
  • 総務省：生体電磁環境研究及び電波の安全性に関する評価技術研究
    Date (from‐to) : 2021/07 -2025/03 
    Author : 日景 隆
  • Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (C)
    Date (from‐to) : 2019/04 -2022/03 
    Author : Hikage Takashi
     
    Wireless devices such as mobile phones, wifi, and wireless power transfer systems are essential to creating the ubiquitous and universal network society. These devices emit electromagnetic fields (EMFs) that can potentially cause electromagnetic interference (EMI) for other electronic devices. The EMI on active implantable medical devices (AIMDs) such as implantable cardiac pacemakers and cardioverter-defibrillators (ICDs) is one of the most important issues needing detailed investigation.This is because EMI on AIMDs can occur even with the potentially lower EMF level provided by the international safety standards for RF exposure. In this study, an interference voltage sensor for AIMD EMI assessment was developed using electrical-to-optical converter technique. Furthermore, measurement of the interference voltage of a pacemaker in the RF frequency band for several kinds of wireless devices including newly developed wireless power transfer using the measurement setup is demonstrated.
  • Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research Fund for the Promotion of Joint International Research (Fostering Joint International Research (B))
    Date (from‐to) : 2019/02 -2021/03 
    Author : Miyanaga Yoshikazu
     
    In this study, multi-media IoT (Internet of Things) network has been proposed and designed. The target media are both of image/video and acoustic/speech data. In particular, the optimum cognitive wireless method has been designed. In this method, the optimum wireless communication can be kept with a self-organized control mechanism. All systems have been designed with low-power consumption architecture and thus the total system realize the lowest power consumption. It is also shown that its design is suitable for natural energy harvesting model.
  • 準ミリ波・ミリ波ばく露時の生体作用の調査
    総務省：生体電磁環境研究及び電波の安全性に関する評価技術研究
    Date (from‐to) : 2017/04 -2021/03 
    Author : 機関代表, 日景 隆
  • Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (C)
    Date (from‐to) : 2015 -2017 
    Author : Hikage Takashi
     
    Electromagnetic fields from the wireless technology devices, when they are employed in our living environment, raises concern that they may cause other electronic devices to malfunction due to electromagnetic interference (EMI). The EMI faced by active implantable medical devices (AIMDs) has become a very controversial issue in recent years. Development of numerical estimation method on AIMDs EMI, development of novel AIMDs EMI simulator equipment that can treat frequency filter characteristics due to internal circuit, and feasibility study for these newly developed EMI estimation technology were carried out in this study. These expertise can be expected to contribute newly mitigation technique for AIMDs EMI developed in the future.
  • Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (C)
    Date (from‐to) : 2012 -2014 
    Author : HIKAGE TAKASHI
     
    Radio-frequency identification (RFID) technology that supports non-contact automatic recognition along with fast data reading, multi-target recognition and invisible recognition, is expected to be an essential component for realizing ubiquitous society. However, the electromagnetic fields from the devices, when they are employed in our living environment, raises concern that they may cause other electronic devices to malfunction due to electromagnetic interference (EMI). The EMI faced by active implantable medical devices (AIMDs) has become a very controversial issue in recent years. A fundamental study on next generation tag interrogator which was applied mm-wave and superconducting filter technology was carried out in this research that was expected to achieve improved high-sensitivity and low-EMI capability from the stand point of AIMDs EMI issues in particular.
  • Ministry of Education, Culture, Sports, Science and Technology：Grants-in-Aid for Scientific Research(若手研究(B))
    Date (from‐to) : 2008 -2009 
    Author : Takashi KIKAGE
     
    Lightweight scattering component that can be applied for high-speed indoor wireless communications was proposed. Fundamental material composites were silicone rubber, metal and carbon nanotubes. In addition, precise propagation characteristic estimation method in WLAN office environments that consisted of multiple objects was developed based on large scaled numerical simulation. The validity of the chosen estimation method in large and complex multi-reflective environments was established by comparing calculation data obtained using this method with data obtained experimentally. Also in cas...
  • Ministry of Education, Culture, Sports, Science and Technology：Grants-in-Aid for Scientific Research(基盤研究(C))
    Date (from‐to) : 2007 -2009 
    Author : Manabu YAMAMOTO, 野島 俊雄, 日景 隆, Toshio NOJIMA, Takashi HIKAGE
     
    Ultra-wideband (UWB) radio systems have recently attracted considerable attention for wireless high-speed communication. The purpose of this study is to present fundamental techniques for the realization of basic components (antenna, filter and microwave amplifier) that are useful for UWB radio systems. The achievements obtained in this study are the development of effective way for constructing ultra-wideband planar-type antennas, the proposal of techniques for obtaining ultra-high efficiency in microwave amplifiers and the realization of microwave filter having ultra-high performance with...
  • 総務省：電波資源拡大のための研究開発
    Date (from‐to) : 2005/04 -2008/03 
    Author : 日景 隆
  • 総務省：戦略的情報通信研究開発推進制度(SCOPE)若手先端IT研究者育成型研究開発
    Date (from‐to) : 2004/04 -2006/03 
    Author : 日景 隆
  • 文部科学省：科学研究費補助金(若手研究(B))
    Date (from‐to) : 2004 -2006 
    Author : 日景 隆
     
    ユビキタス環境実現のキーデバイスの一つとして無線タグあるいはRFIDタグ(Radio Frequency Identification)が注目されている.本研究では,RFID用アンテナの小型化・高効率化を目的として検討を行っている.開発する小型高効率アンテナについて,計算機シミュレーションおよび実験の両面から検討し,さらに時間領域電磁界解析(FDTD)法を用いた仮想電波伝搬環境を実現し,アンテナ設計および伝搬特性評価を行った.(1)アクティブRFID用のアンテナ素子として,背面に地板を有するメアンダ状ダイポールアンテナ(以下MDA)の検討を行った.背面に地板を有し,線路上に装荷されたアクティブ素子によりアンテナ特性を適切に制御する小型平面アンテナの開発を行った。開発したアンテナは,金属板等に貼り付けた場合でも十分な利得を有しておりタグの読取精度向上とRFID適用領域の拡大を実現するものである.(2)現行RFIDタグの運用において最も重要な課題となっていることが読み取り誤差の極小化である.タグとRFIDリーダ/ライタ間において確実な送受信を実現するためには,周囲環境を評価に含めたアンテナデザインツールの開発が不可欠である.そこで,RFIDタグおよび読み取り機が存在する実空間を評価するための電磁界解析ツールを開発した.開発した大規模電磁界解析手法を用い,RFIDタグとリーダ/ライ...
  • Ministry of Education, Culture, Sports, Science and Technology：Grants-in-Aid for Scientific Research(基盤研究(C))
    Date (from‐to) : 2000 -2002 
    Author : Manabu OMIYA, 伊藤 精彦, 日景 隆, 山本 学
     
    The cavity-backed slot antenna is used as a microwave energy transmission antenna element for solar power satellites. The antenna element has advantags over other types of antenna in mechanical strength, heat dissipation and a low profile structure. We propose new types of cavity-backed slot antenna consisting of two conductive plates separated by thin wires or thick pillars.First we show an effective design method of an antenna element with the height of 3 mm excited by the short-ended probe and derived two kinds of antenna parameter for the element with finite and infinite conductive plat...
  • Ministry of Education, Culture, Sports, Science and Technology：Grants-in-Aid for Scientific Research(基盤研究(A))
    Date (from‐to) : 1999 -2002 
    Author : 伊藤 精彦, Manabu YAMAMOTO, 山本 学, 大宮 学, 日景 隆, 稲川 清, 伊藤 精彦, 村本 充
     
    Our research group obtained the following results that contribute greatly to the development of millimeter-wave wireless local area network systems.1. As a basic element of millimeter-wave planar-type sector antennas, a printed slot array with backward excitation was developed. A novel configuration for constructing a planar-type sector antenna using this array was also proposed. The effectiveness of the proposed techniques has been confirmed with numerical and experimental manner.2. A printed slot Yagi-Uda array was proposed, and a planar-type sector antenna made by this array was investig...
  • 文部科学省：科学研究費補助金(奨励研究(A))
    Date (from‐to) : 2000 -2001 
    Author : 日景 隆
     
    本奨励研究においては,側面をポストで構成したキャビティ付スロットアンテナの開発研究を行った.キャビティ付スロットアンテナとは,直方体のキャビティ(空洞共振器)の適当な面にスロットと呼ばれる開口部を設け,アンテナとしたものである.マイクロ波エネルギー伝送においてはこれらアンテナを数100〜1000素子から構成される巨大なアレーアンテナを使用する.したがって,製造および構成が単純でなければならない.しかしながら,キャビティ側面と上下の地板の電気的接続は容易ではない.このようなことから,キャビティ側面をポスト(ワイヤ)により構成することにより,電気的な特性を劣化させることなく製造が容易にできるのではないかと考え,検討を行った.本研究においては,本年度次に示す成果を得ている.アンテナ素子側壁を構成するポスト間隔を狭くすることで,側壁が導体板の場合と同様の特性が得ることができる.しかしながら,必要なポスト本数が増加し,容易な製造を実現できない.よって,所望の特性を実現可能なポスト間隔を明らかにする必要がある.ここで,送電アンテナ素子の寸法はx軸方向に75mm,y軸方向に90mmであり,高さは特に指定されていない.本研究においては,高さ12mmのアンテナ素子を仮定し,ポスト間隔Δについて検討した.Δが3mm,7.5mmおよび15mmのいずれの場合についても,送電周波数2.45GHzで20...
  • 太陽発電衛星用送受電アンテナ技術
  • 生体ラジカルに与えるマイクロ波影響
  • 準閉空間における電磁界評価技術の研究
  • RFID用小型無線チップ技術の研究

Educational Activities

Teaching Experience

  • Radio-frequency (RF) engineeringRadio-frequency (RF) engineering Hokkai-Gakuen University
  • 環境と人間 ２０３０年エレクトロニクスの旅環境と人間 ２０３０年エレクトロニクスの旅 Hokkaido University
  • Introduction to Informatics IIIntroduction to Informatics II Hokkaido University
  • Complex Systems ModelingComplex Systems Modeling Hokkaido University
  • Freshman SeminarFreshman Seminar Hokkaido University
  • Freshman Seminar
    開講年度 : 2021
    課程区分 : 学士課程
    開講学部 : 全学教育
    キーワード : 携帯電話，スマートフォン，5G，Wi-Fi，IoT, ワイヤレス給電，電波防護

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