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Master

Affiliation (Master)

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

Affiliation (Master)

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

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Profile and Settings

Profile and Settings

  • Name (Japanese)

    Yamamoto

  • Name (Kana)

    Manabu

  • Name

    201301022063132700

Alternate Names

Achievement

Research Interests

  • 準光学アンテナ・ミキサ   ミリ波   スペクトル領域モーメント法   バックワード励振   UWB無線システム   平面構造   無線LAN   超広帯域アンテナ   アンテナ   プリントスロットアレー   イメージNRDガイド   キャビティ   平面マルチセクタアンテナ   スロット八木・宇田アレー   プリントスロットアンテナ   マイクロストリップ線路   FDTD法   誘電体ロッドアンテナ   ファンビーム   ペンシルビーム   マイクロ波   共振型漏れ波アンテナ   UWBレーダー   電磁結合パッチアンテナ   FDTD解析   自己補対アンテナ   高効率増幅器   ミリ波無線LAN   プリントスロット八木・宇田アレー   自己補対型放射素子   

Research Areas

  • Manufacturing technology (mechanical, electrical/electronic, chemical engineering) / Communication and network engineering

Research Experience

  • 2011 北海道大学 大学院・情報科学研究科 准教授

Awards

  • 2012/12 電子情報通信学会 アンテナ・伝播研究専門委員会 功労賞
     
    受賞者: 山本学
  • 2012/06 電子情報通信学会 アンテナ・伝播研究専門委員会 功労賞
     
    受賞者: 山本学
  • 2010/09 電子情報通信学会 通信ソサイエティ 電子情報通信学会通信ソサイエティ活動功労賞
     
    受賞者: 山本学
  • 2006/09 電子情報通信学会 通信ソサイエティ 電子情報通信学会通信ソサイエティ優秀論文賞
     
    受賞者: 山本学;飴谷充隆;野島俊雄;伊藤精彦
  • 2005/09 電子情報通信学会 通信ソサイエティ 電子情報通信学会通信ソサイエティ 活動功労賞
     
    受賞者: 山本学
  • 1998/03 電子情報通信学会 電子情報通信学会学術奨励賞
     
    受賞者: 山本学

Published Papers

  • 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
  • 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.
  • Mangseang Hor, Takashi Hikage, Manabu Yamamoto
    IEICE Transactions on Communications advpub 0916-8516 2022/03 [Refereed][Not invited]
     
    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.
  • 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 電子情報通信学会 J105-B (3) 166 - 177 2022/03 [Refereed][Not invited]
     
    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.
  • YAMAMOTO Naoya, HIKAGE Takashi, YAMAMOTO Manabu
    電子情報通信学会論文誌B 電子情報通信学会 J105-B (3) 310 - 312 2022/03 [Refereed][Not invited]
     
    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.
  • Linear Array of Leaf-Shaped Bowtie Slot Antenna Electromagnetically Fed by Microstrip Line
    Mangseang Hor, Takashi Hikage, Manabu Yamamoto
    proc. of The 26th International Symposium on Antennas and Propagation (ISAP2021) (220053) 2021/10 [Refereed][Not invited]
  • A Wideband Planar Array Antenna Using Both- Sided MIC and Leaf-Shaped Bowtie Slot Elements
    Naoya Yamamoto, Mangseang Hor, Takashi Hikage, Manabu Yamamoto
    proc. of The 26th International Symposium on Antennas and Propagation (ISAP2021) (220080) 2021/10 [Refereed][Not invited]
  • Shunichi Futatsumori, Kazuyuki Morioka, Takashi Hikage, Tetsuya Sekiguchi, Manabu Yamamoto, Toshio Nojima
    2021 International Applied Computational Electromagnetics Society Symposium, ACES 2021 2021/08/01 
    Wireless avionics intra-communication (WAIC) system will be operated at a frequency between 4, 200-4, 400 MHz, which is same frequency band as aircraft radio altimeters. Following the standard document, the electromagnetic field from the WAIC devices is required to be evaluated on the hemisphere surface, which is positioned on the geometrical center of the aircraft. This paper analyzes the electric field (E-field) strength on the hemisphere around the aircraft, assuming the WAIC device is inside the cabin using large-scale finite-difference time-domain analysis. In this study, we explain the E-field strength estimation method on the hemisphere around the three-dimensional model of Airbus A320-200. Further, we discuss E-field distributions on the hemisphere based on the analysis results.
  • 誘電体基板上に配置された広帯域矩形ループアンテナ
    鴫原 達郎, 山本 尚也, 関口 徹也, 山本 学
    電子情報通信学会論文誌B J104-B (7) 633 - 635 2021/07 [Refereed][Not invited]
  • Tatsuro Shigihara, Takashi Hikage, Manabu Yamamoto, Kento Yoshizawa, Kazumitsu Sakamoto
    Proc. of 2020 International Symposium on Antennas and Propagation (4D3-6) 811 - 812 2021/01 [Refereed][Not invited]
     
    This paper presents a study on beam narrowing and gain enhancement of a patch array antenna by loading Frequency Selective Surface (FSS) consisting of periodic arrangement of rectangular dipoles. The dipole element is designed so that its length get shorter towards the end of the antenna to equalize the phase distribution on the aperture surface. Antenna characteristics are evaluated by performing the finite-difference time domain (FDTD) analysis for the case when the main beam direction of the patch array antenna is the broadside and when the main beam direction is tilted from the broadside. From the simulated results, beam narrowing and gain enhancement are confirmed for the above-mentioned cases.
  • Leaf-Shaped Bowtie Slot Antenna Array for Application in Beam Scanning
    Mangseang Hor, Takashi Hikage, Manabu Yamamoto
    Proc. of 2020 International Symposium on Antennas and Propagation (4B3-5) 2021/01 [Refereed][Not invited]
  • Shunichi Futatsumori, Kazuyuki Morioka, Takashi Hikage, Tetsuya Sekiguchi, Manabu Yamamoto, Toshio Nojima
    Applied Computational Electromagnetics Society Journal 35 (11) 1274 - 1275 1054-4887 2020/11 
    The equivalent isotopically radiated power (EIRP) of a wireless avionics intra-communication (WAIC) system is limited to 6 dBm/MHz at the geometrical center of the aircraft, to avoid interference with aircraft radio altimeters, which are operated at the same frequency band between 4,200–4,400 MHz. In this paper, the height and angle characteristics of the point source EIRP of a WAIC system are analyzed based on the large scale FDTD analysis. Firstly, the strength of the electric field (E-field) around the three-dimensional model of Airbus A320-200 is analyzed. Then, the point source EIRP is calculated based on the analyzed E-field strength. Finally, the height and angle characteristics are analyzed to estimate the electromagnetic field characteristics of the aircraft.
  • Shunichi Futatsumori, Nxorihiko Miyazaki, Takashi Hikage, Tetsuya Sekiguchi, Manabu Yamamoto, Toshio Nojima
    Proceedings of the 2020 International Symposium on Electromagnetic Compatibility - EMC EUROPE, EMC EUROPE 2020 2020/09/23 
    Wireless Avionics Intra-Communication (WAIC) devices operate between 4,200 MHz and 4,400 MHz. This is the same frequency band as aircraft radio altimeters. In this paper, to investigate the coexistence conditions, the radio altimeter interference path loss (IPL) due to an assumed WAIC device is investigated. Firstly, an overview of the Beechcraft B300, a medium sized turboprop aircraft, is given. Then, the radio altimeter IPL measurement set-up is discussed. The measurement set-up and procedures are based on the RTCA DO-307A procedure. Finally, the IPL values are calculated using the measurement results. The minimum IPL value with the transmitting antenna inside of the cabin is 72.8 dB. This is not significantly small compared with that of the Airbus A321 (74.4 dB). In addition, the median IPL value with the transmitting antenna inside of the cabin is 90.9 dB.
  • R. Keshavarz, Y. Miyanaga, M. Yamamoto, T. Hikage, N. Shariati
    2020 33rd General Assembly and Scientific Symposium of the International Union of Radio Science, URSI GASS 2020 2020/08 
    A new compact quad-band notch filter (QBNF) based on the extended composite right and left-handed transmission line (E-CRLH TL) has been presented. As known, E-CRLH TL behaves like a quad-band structure. A microstrip TL which is loaded with an open-ended ECRLH TL is presented as a QBNF. Four unwanted frequencies were used in a dual-band LTE receiver as four notch frequencies which must be eliminated (0.9 GHz, 1.3 GHz, 2.55 GHz, and 3.35 GHz). Also, this QBNF can be applied to simultaneous wireless power and data transfer (SWPDT) system to isolate the wireless power circuit from the data communication circuit. A design technique for the proposed QBNF is presented and its performance is validated using full-wave simulation results and theoretical analysis. The main advantage of this design is an overall rejection greater than 20dB at selected unwanted frequencies. Good agreements between the fullwave simulation and equivalent circuit model results have been achieved which verified the effectiveness of the proposed circuit model. The proposed QBNF is designed on an FR-4 substrate and the dimension of the proposed QBNF is 20 * 22 mm.
  • Shunichi Futatsumori, Kazuyuki Morioka, Takashi Hikage, Tetsuya Sekiguchi, Manabu Yamamoto, Toshio Nojima
    2020 International Applied Computational Electromagnetics Society Symposium, ACES-Monterey 2020 2020/07 
    The equivalent isotopically radiated power (EIRP) of a wireless avionics intra-communication (WAIC) system is limited to 6 dBm/MHz at the geometrical center of the aircraft, to avoid interference with aircraft radio altimeters, which are operated at the same frequency band between 4,200-4,400 MHz. In this paper, the height and angle characteristics of the point source EIRP of a WAIC system are analyzed based on the large scale FDTD analysis. Firstly, the strength of the electric field (E-field) around the three-dimensional model of Airbus A320-200 is analyzed. Then, the point source EIRP is calculated based on the analyzed E-field strength. Finally, the height and angle characteristics are analyzed to estimate the electromagnetic field characteristics of the aircraft.
  • A Study on Gain Enhancement of a Leaf-Shaped Bowtie Slot Antenna Array Employing Dielectric Superstrates
    Takuma Makanae, Manabu Yamamoto
    Proceedings of 2019 International Symposium on Antennas and Propagation (TA1D) 2019/10 [Refereed][Not invited]
  • Shunichi Futatsumori, Kazuyuki Morioka, Takashi Hikage, Tetsuya Sekiguchi, Manabu Yamamoto, Toshio Nojima
    2019 International Applied Computational Electromagnetics Society Symposium in Miami, ACES-Miami 2019 2019/05/10 
    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.
  • 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.
  • 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
    電子情報通信学会論文誌 B Vol.J102-B (No. 2) 72 - 79 2019/02 [Refereed][Not invited]
  • 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 2019/01/01 [Refereed][Not invited]
     
    © 2019 Applied Computational Electromagnetics Society (ACES). All rights reserved. Radio altimeters and wireless avionics intracommunication (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 timedomain 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.
  • 地板上矩形ループアンテナの2周波共用化
    野村 早希, 山本 学
    電子情報通信学会論文誌B J101-B (9) 790 - 792 2018/09 [Refereed][Not invited]
  • Estimation of SAR Enhancement Due to Implant Metal Exposed to External Electromagnetic Waves
    Emi Matsuda, Keita Sakakibara, Takashi Hikage, Manabu Yamamoto and Toshio Nojima
    proc. of 2018 IEEE International Workshop on Electromagnetics: Applications and Student Innovation Competition (POS2.47) 2018/08 [Refereed][Not invited]
  • Design of a Dual-Frequency Rectangular Loop Antenna Placed on a Ground Plane
    Hayaki Nomura, Manabu Yamamoto
    Proc. of IEEE AP-S/URSI 2018 (TU-A1.1A.2) 2018/07 [Refereed][Not invited]
  • Design of a Wideband 6-Port MIMO Antenna Array Consisting of Leaf-Shaped Radiating Elements
    Jumpei Motohashi, Takashi Hikage, Manabu Yamamoto
    Proceedings of the 2017 Asian Workshop on Antennas and Propagation (P1-09) 23 - 24 2017/06 [Refereed][Not invited]
  • Shunichi Futatsumori, Kazuyuki Morioka, Akiko Kohmura, Naruto Yonemoto, Takashi Hikage, Kanji Yahagi, Masami Shirafune, Manabu Yamamoto, Toshio Nojima, Shoichi Narahashi
    2017 International Applied Computational Electromagnetics Society Symposium - Italy, ACES 2017 2017/05/01 
    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.
  • Kanji Yahagi, Masami Shirafune, Takashi Hikage, Manabu Yamamoto, Toshio Nojima, Shoichi Narahashi, Syunichi Futatsumori, Akiko Kohmura, Naruto Yonemoto
    2016 INTERNATIONAL SYMPOSIUM ON ANTENNAS AND PROPAGATION (ISAP) 566 - 567 2016 [Refereed][Not invited]
     
    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.
  • 直並列給電回路と葉状ボウタイ素子を用いた広帯域アレーアンテナ
    山本 学, 棟形 丈仁, 野島 俊雄
    電子情報通信学会論文誌C J98-C (12) 447 - 450 2015/12 [Refereed][Not invited]
  • A Wideband MIMO Antenna Using Leaf-Shaped Monopole and Notch Antennas
    Manabu Yamamoto, Shohei Maeda
    Proceedings of 2015 International Symposium on Antennas and Propagation (S5.7-4) 2015/11 [Refereed][Not invited]
  • 葉状ボウタイ素子を用いた4ポート広帯域MIMOアンテナ
    前田 将平, 山本 学, 野島 俊雄
    電子情報通信学会論文誌B J98-B (9) 886 - 895 2015/09 [Refereed][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 [Refereed][Not invited]
     
    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
  • Fundamentals and Practice of Printed Antennas
    Manabu Yamamoto
    電子情報通信学会論文誌 B J97-B (9) 714 - 730 2014/09 [Refereed][Invited]
  • Manabu Yamamoto, Toshio Nojima
    2014 INTERNATIONAL SYMPOSIUM ON ANTENNAS AND PROPAGATION (ISAP) (TH2D_01) 261 - 262 2014 [Refereed][Not invited]
     
    This paper presents a design of a wideband printed antenna being useful for ultra-wideband applications. In the designed antenna that operates over the frequency band of 7-10 GHz, a leaf-shaped bowtie slot antenna (LSBSA) is employed as a radiating element, and electromagnetic coupling feed based on a microstrip line is adopted for the excitation of the radiating element. In order to demonstrate the effective performance of the presented configuration, characteristics of the designed LSBSA are evaluated by the finite-difference time domain (FDTD) analysis. Over the above-mentioned frequency band, the simulated reflection coefficient is observed to be less than -10 dB, and the maximum actual gain of 7.5 dBi is obtained. Measured results are also presented in order to validate the simulated results.
  • Takehito Munekata, Manabu Yamamoto, Toshio Nojima
    2014 IEEE INTERNATIONAL WORKSHOP ON ELECTROMAGNETICS (IEEE IWEM): APPLICATIONS AND STUDENT INNOVATION COMPETITION 80 - 81 2014 [Refereed][Not invited]
     
    This paper presents a design of a quasi-millimeter wave wideband antenna array consisting of a leaf-shaped bowtie antenna (LSBA) and series-parallel feed networks in which parallel strip and microstrip lines are employed. A 16-element LSBA array is designed such that the antenna array operates over the frequency band of 22-30GHz. In order to demonstrate the effective performance of the presented configuration, characteristics of the designed LSBA array are evaluated by the finite-difference time domain (FDTD) analysis and measurements. Over the frequency range from 22GHz to 30GHz, the simulated reflection coefficient is observed to be less than -8dB, and the actual gain of 12.3-19.4dBi is obtained.
  • Manabu Yamamoto, Soh Fujita, Jun Kimura, Toshio Nojima
    Proceedings of the 2013 IEEE-APS Topical Conference on Antennas and Propagation in Wireless Communications, IEEE APWC 2013 448 - 451 2013 [Refereed][Invited]
     
    This paper presents a design of a wideband array antenna consisting of a leaf-shaped bowtie slot antenna (LSBSA). A four-element LSBSA array is designed such that the array operates over the frequency band of 7-10GHz. In order to demonstrate the effective performance of the presented configuration, characteristics of the designed LSBSA array are evaluated by the finite-difference time domain (FDTD) analysis. Over the frequency band from 7GHz to 10GHz, the simulated reflection coefficient is observed to be less than -8dB, and the actual gain of 10-12dBi is obtained. Measured results for the prototype array antenna are also presented in order to confirm the validity of the simulated results obtained by the FDTD analysis. © 2013 IEEE.
  • A Study of a Leaf-Shaped Bowtie Slot Antenna for UWB Applications
    Soh Fujita, Manabu Yamamoto, Toshio Nojima
    Proc. of 2012 International Symposium on Antennas and Propagation (3B3-1) 830 - 833 2012/11 [Refereed][Not invited]
  • 葉状ボウタイ素子を用いたMIMO用アンテナに関する基礎検討
    木村 準, 山本 学, 野島 俊雄
    平成24年度電気・情報関係学会北海道支部連合大会講演論文集 97  2012/10 [Not refereed][Not invited]
  • 葉状ボウタイスロットアレーアンテナの特性評価
    藤田 壮, 山本 学, 野島 俊雄
    平成24年度電気・情報関係学会北海道支部連合大会講演論文集 96  2012/10 [Not refereed][Not invited]
  • YAMAMOTO Manabu, FUJITA So, NOJIMA Toshio
    電子情報通信学会論文誌. B, 通信 電子情報通信学会通信ソサイエティ 95 (9) 1181 - 1184 1344-4697 2012/09 [Refereed][Not invited]
     
    葉状ボウタイスロットアンテナについて,諸特性をFDTD解析及び測定により明らかにする.はじめに,UWBハイバンド(7〜10 GHz)を動作周波数とする葉状ボウタイスロットを設計し,アンテナ中央部に給電点を配置した場合の反射係数を評価する.その結果を踏まえて,上記帯域における整合が可能な給電回路の構成について検討する.給電回路を介してアンテナを励振した場合の諸特性をFDTD解析により評価するとともに,測定結果との比較を行い,提案アンテナの有効性を確認する.
  • 木村 準, 山本 学, 野島 俊雄
    電子情報通信学会技術研究報告 : 信学技報 電子情報通信学会 112 (149) 7 - 12 0913-5685 2012/07 [Not refereed][Not invited]
  • YAMAMOTO Manabu, KOYANAGI Tomoyuki, Fujita So, NOJIMA Toshio
    Proceedings of the IEICE General Conference 一般社団法人電子情報通信学会 2012 (1) 160 - 160 2012/03 [Not refereed][Not invited]
  • Manabu Yamamoto, Tomoyuki Koyanagi, Soh Fujita, Toshio Nojima
    2012 IEEE ANTENNAS AND PROPAGATION SOCIETY INTERNATIONAL SYMPOSIUM (APSURSI) (258.4) 1522-3965 2012 [Refereed][Not invited]
     
    This paper presents a design of a quasi-millimeter wave array antenna consisting of a leaf-shaped bowtie antenna (LSBA) and a mushroom-type electromagnetic band gap (EBG) substrate. A four-element LSBA array backed by the mushroom-type EBG substrate is designed such that the array operates at the frequency band from 22 to 29GHz. In order to demonstrate the effective performance of the presented configuration, characteristics of the designed LSBA array are evaluated by the finite-difference time domain (FDTD) analysis. For comparison, the performances for the LSBA array backed by a perfect electric conductor (PEC) are also presented. From the simulated results, it is confirmed that the gain for the LSBA array with the EBG substrate is greater than that for the array backed by the PEC reflector within the operating design frequency band.
  • FUJITA So, YAMAMOTO Manabu, NOJIMA Toshio
    IEICE technical report. Antennas and propagation 一般社団法人電子情報通信学会 111 (343) 29 - 34 0913-5685 2011/12 [Not refereed][Not invited]
     
    As a planar-type wideband antenna being useful for UWB radio systems, the authors have previously proposed a wideband dipole antenna being composed of leaf-shaped bowtie radiating elements. In this report, a leaf-shaped bowtie slot antenna, which is a complementary structure of the above-mentioned dipole antenna, is proposed and its characteristics are revealed by FDTD analysis and measurements. In the first place, the antenna having the operating frequency band from 7 to 10GHz (UWB high band) is designed, and its reflection coefficient is evaluated for the case when the feeding point is ar...
  • UWB無線用葉状ボウタイスロットアンテナに関する基礎検討
    藤田 壮, 山本 学, 野島 俊雄
    平成23年度電気・情報関係学会北海道支部連合大会講演論文集 92  2011/10 [Not refereed][Not invited]
  • マッシュルーム型EBG基板上の4素子葉状ボウタイアレーアンテナ
    小柳 智之, 山本 学, 野島 俊雄
    平成23年度電気・情報関係学会北海道支部連合大会講演論文集 91  2011/10 [Not refereed][Not invited]
  • KOYANAGI Tomoyuki, YAMAMOTO Manabu, NOJIMA Toshio
    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 94 (9) 1133 - 1145 1344-4697 2011/09 [Refereed][Not invited]
     
    UWB無線のための平面型広帯域アンテナとして,筆者らは過去に葉状ボウタイアンテナを提案した.また,同アンテナを反射板上に適切な間隔で配置することにより,広帯域な単一指向性アンテナとして動作することを示した.本論文では,反射板としてマッシュルーム構造と,同構造からビアを取り除いた周期パッチ装荷導体板を用いた葉状ボウタイアンテナについて,諸特性をFDTD解析により明らかにする.マッシュルーム構造と周期パッチ装荷導体板の両者に関して,共振周波数を適切に設定することにより,アンテナの動作帯域の高域側において生じる放射特性の劣化を回避できることを示している.
  • KOYANAGI Tomoyuki, YAMAMOTO Manabu, NOJIMA Toshio
    Proceedings of the Society Conference of IEICE 一般社団法人電子情報通信学会 2011 (1) 139 - 139 2011/08 [Not refereed][Not invited]
  • KOYANAGI Tomoyuki, YAMAMOTO Manabu, NOJIMA Toshio
    Proceedings of the IEICE General Conference 一般社団法人電子情報通信学会 2011 (1) 144 - 144 2011/02 [Not refereed][Not invited]
  • Manabu Yamamoto, Tomoyuki Koyanagi, Toshio Nojima
    2011 IEEE INTERNATIONAL SYMPOSIUM ON ANTENNAS AND PROPAGATION (APSURSI) (205.5) 622 - 625 1522-3965 2011 [Refereed][Not invited]
     
    As a planar-type wideband antenna being useful for UWB radio systems, the authors have previously proposed a leaf-shaped bowtie antenna. In this paper, we present a design of a leaf-shaped bowtie antenna in which a periodic patch-loaded grounded slab is used in order to realize a unidirectional beam over a wide frequency range while maintaining a low-profile configuration. In order to demonstrate effective performance of the presented configuration, fundamental characteristics of the antenna are investigated and revealed by the finite-difference time domain (FDTD) analysis and measurements.
  • A Study of a Leaf-Shaped Bowtie Antenna Backed by an Electromagnetic Band Gap Structure
    Tomoyuki Koyanagi, Manabu Yamamoto, Toshio Nojima
    Proc. of 2010 International Symposium on Antennas and Propagation (114) 2010/11 [Refereed][Not invited]
  • MATSUSHIMA Toshikazu, YAMAMOTO Manabu, NOJIMA Toshio
    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 93 (9) 1283 - 1287 1344-4697 2010/09 [Refereed][Not invited]
     
    UWB無線は無線LANと相互干渉を起こす可能性が高いと考えられることから,無線LANの使用周波数帯に阻止帯域を有するUWBアンテナが求められている.本論文では,5GHz帯に阻止帯域を有する小形葉状ボウタイアンテナを提案し,その特性をFDTD解析及び実験により明らかにする.
  • TOKUYAMA Daisuke, YAMAMOTO Manabu, NOJIMA Toshio
    Proceedings of the Society Conference of IEICE 一般社団法人電子情報通信学会 2010 (1) 162 - 162 2010/08 [Not refereed][Not invited]
  • KOYANAGI Tomoyuki, YAMAMOTO Manabu, NOJIMA Toshio
    IEICE technical report. Antennas and propagation 一般社団法人電子情報通信学会 110 (135) 143 - 148 0913-5685 2010/07 [Not refereed][Not invited]
     
    As an planar-type wideband antenna being useful for UWB radio, the authors have previously proposed a leaf-shaped bowtie antenna. It have been also demonstrated by the authors that unidirectional radiation characteristics can be achieved over a wide frequency band when the antenna is placed parallel to a reflector at an appropriate distance. In this report, we evaluate and clarify the characteristics of the leaf-shaped bowtie antenna by performing FDTD analysis and measurements for two cases when the antenna is backed by a mushroom-type EBG (Electromagnetic Band-Gap) substrate or by a patch...
  • TOKUYAMA Daisuke, MATSUSHIMA Toshikazu, YAMAMOTO Manabu, NOJIMA Toshio
    Proceedings of the IEICE General Conference 一般社団法人電子情報通信学会 2010 (1) "S - 2" 2010/03 [Not refereed][Not invited]
  • Manabu Yamamoto, Daisuke Tokuyama, Toshio Nojima
    2010 IEEE ANTENNAS AND PROPAGATION SOCIETY INTERNATIONAL SYMPOSIUM (529.5) 1522-3965 2010 [Refereed][Not invited]
  • Ultra-Wideband Leaf-Shaped Bowtie Antenna with Band-Rejected Characteristics
    Toshikazu Matsushima, Manabu Yamamoto, Toshio Nojima
    Proc. of 2009 International Symposium on Antennas and Propagation 959 - 962 2009/10 [Refereed][Not invited]
  • KIMURA Kouichirou, YAMAMOTO Manabu, NOJIMA Toshio
    Proceedings of the Society Conference of IEICE 一般社団法人電子情報通信学会 2009 (1) 62 - 62 2009/09 [Not refereed][Not invited]
  • MATSUSHIMA Toshikazu, YAMAMOTO Manabu, NOJIMA Toshio
    IEICE technical report. Antennas and propagation 一般社団法人電子情報通信学会 109 (117) 1 - 6 0913-5685 2009/07 [Not refereed][Not invited]
     
    The authors have previously proposed a planar-type UWB antenna consisting of leaf-shaped bowtie radiating elements and a tapered microstrip line. Over the frequency band allocated for UWB radio systems, there are existing bands used by wireless local-area networks (WLAN) operating in 5GHz band. In order to avoid the interference between the UWB and WLAN systems, it is required to develop UWB antennas with a 5GHz band rejection. In this report, we present band-rejected structures for the leaf-shaped bowtie antenna. By connecting band-notched filter consisting of X-shaped strips in shunt with...
  • MATSUSHIMA Toshikazu, YAMAMOTO Manabu, NOJIMA Toshio
    Proceedings of the IEICE General Conference 一般社団法人電子情報通信学会 2009 (1) 179 - 179 2009/03 [Not refereed][Not invited]
  • A Study on Unidirectional UWB Array Antenna Composed of Leaf-Shaped Bowtie Elements
    Manabu Yamamoto
    The 10th International Joint Symposium between Hokkaido University and Chungnam National University 91 - 99 2008/10 [Not refereed][Not invited]
  • Unbalanced Fed Dipole Antenna Mounted on Ground Plane with L-shaped Parasitic Elements for Mobile Handsets
    Youhei Okada, Manabu Yamamoto, Toshio Nojima
    Proc. of 2008 International Symposium on Antennas and Propagation 1523 - 1526 2008/10 [Refereed][Not invited]
  • OKADA Youhei, YAMAMOTO Manabu, NOJIMA Toshio
    Proceedings of the Society Conference of IEICE 一般社団法人電子情報通信学会 2008 (1) 143 - 143 2008/09 [Not refereed][Not invited]
  • ITO Yoshinori, AMEYA Michitaka, YAMAMOTO Manabu, NOJIMA Toshio
    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 91 (9) 1029 - 1036 1344-4697 2008/09 [Refereed][Not invited]
     
    本論文では,反射板付き葉状ボウタイUWBアンテナの二次元アレー化に関する検討を行う.はじめに,デルタギャップ給電の場合において最も広帯域な利得特性が得られる素子間隔と反射板間隔につき,FDTD解析により検討する.この結果に基づいて設計された4素子の二次元アレーアンテナについて,テーパ状のマイクロストリップ線路と2段の平衡ストリップ線路T分岐から構成される給電回路を用いて給電した場合の反射係数,利得及び伝送特性を測定とFDTD解析により明らかにする.また,テンプレート波形と受信波形の相関値を用いて提案アンテナの波形ひずみを定量的に評価する.更に,低マルチパス室内環境においてアンテナ間の伝送特性を測定し,金属板の位置及びアンテナ指向性による性能の違いを波形ひずみの観点から明らかにする.
  • MATSUSHIMA Toshikazu, YAMAMOTO Manabu, NOJIMA Toshio
    IEICE technical report. Antennas and propagation 一般社団法人電子情報通信学会 108 (148) 75 - 80 0913-5685 2008/07 [Not refereed][Not invited]
     
    In this report, a miniaturization technique based on the use of high-permittivity dielectric substrates is applied to a leaf-shaped bowtie antenna for UWB communications. By employing an antenna substrate with a high relative permittivity of 10.2, the antenna size can be reduced by approximately 70 percent in comparison with the case when the antenna is arranged on a dielectric substrate having a low relative permittivity of 2.2. It is also confirmed that wideband characteristics covering the UWB frequency band can be realized even for the case where the antenna is miniaturized by the propo...
  • AMEYA Michitaka, ITO Yoshinori, YAMAMOTO Manabu, NOJIMA Toshio
    Proceedings of the IEICE General Conference 一般社団法人電子情報通信学会 2008 (1) 151 - 151 2008/03 [Not refereed][Not invited]
  • OKADA Youhei, AMEYA Michitaka, YAMAMOTO Manabu, NOJIMA Toshio
    Proceedings of the IEICE General Conference 一般社団法人電子情報通信学会 2008 (1) 130 - 130 2008/03 [Not refereed][Not invited]
  • YAMAMOTO Manabu, MATSUSHIMA Toshikazu, AMEYA Michitaka, NOJIMA Toshio
    Proceedings of the IEICE General Conference 一般社団法人電子情報通信学会 2008 (1) 3 - 3 2008/03 [Not refereed][Not invited]
  • Y. Ito, M. Ameya, M. Yamamoto, T. Nojima
    ELECTRONICS LETTERS 44 (1) 9 - 10 0013-5194 2008/01 [Refereed][Not invited]
     
    A study of a UWB array antenna is presented, which is composed of leaf-shaped bowtie radiating elements printed on a dielectric substrate. With the use of a flat reflector, the presented antenna has unidirectional radiation characteristics and higher directivity in comparison with omnidirectional UWB antennas. In the maximum radiation direction of the proposed antenna, the actual gain of 10.3-13.3 dBi is achieved over the frequency range of 4.1-10.0 GHz (-3 dB gain bandwidth of 91%).
  • YAMAMOTO Manabu, SAITO Yuta, 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 90 (12) 951 - 955 1345-2827 2007/12 [Refereed][Not invited]
     
    切り込みを有する地板上に配置された不平衡給電ダイポールアンテナの特性をFDTD解析により評価する.地板の切り込みによって地板下部の電流が抑制されることと,人体の手部を模擬したファントムに近接時の放射効率が最大で30%程度改善されることを示す.
  • Michitaka Ameya, Manabu Yamamoto, Toshio Nojima, Kiyohiko Itoh
    IEICE TRANSACTIONS ON COMMUNICATIONS E90B (9) 2230 - 2238 0916-8516 2007/09 [Refereed][Not invited]
     
    Recently. a lot of UWB antennas have been reported by many research groups. Most of the reported antennas have onmidirectional radiation characteristics. The disadvantage of using orimidirectional antennas is that the antenna performance can be degraded by adjacent walls or metals. If unidirectional UWB antennas are utilized, the degradation on the antenna performance due to omnidirectionality can be avoided. Another important topic in UWB antennas is the waveform distortion caused by antennas' transmission characteristics. In impulse-based UWB communications, waveform distortions of transmitted and received pulses caused by antennas deteriorate the communication performance. Therefore, the development of UWB antennas having small waveform distortions is highly desirable. In this paper, we propose a novel bowtie antenna using leaf-shaped radiating elements and a flat reflector. This antenna has unidirectional radiation patterns over the frequency range of 3.0 to 10.5 GHz. The actual gain in the maximum radiation direction is 6.0-9.0 dBi, in the frequency range of 4.5-9.4 GHz (relative bandwidth of 71%). The cross-correlations between source pulse and received pulse waveforms are 0.89-0.94, and hence the waveform distortion caused by this antenna is relatively small. As a result, the proposed antenna is useful for impulse-based UWB communication systems using correlation detection.
  • AMEYA Michitaka, ITO Yoshinori, YAMAMOTO Manabu, NOJIMA Toshio
    Proceedings of the Society Conference of IEICE 一般社団法人電子情報通信学会 2007 (1) 101 - 101 2007/08 [Not refereed][Not invited]
  • OKADA Youhei, YAMAMOTO Manabu, NOJIMA Toshio
    Proceedings of the Society Conference of IEICE 一般社団法人電子情報通信学会 2007 (1) 56 - 56 2007/08 [Not refereed][Not invited]
  • ITO Yoshinori, AMEYA Michitaka, YAMAMOTO Manabu, NOJIMA Toshio
    IEICE technical report. Antennas and propagation 一般社団法人電子情報通信学会 107 (144) 7 - 12 0913-5685 2007/07 [Not refereed][Not invited]
     
    We have previously proposed a unidirectional leaf-shaped bowie antenna for UWB application and investigated the characteristics of the antenna. In this paper, we discuss the two-dimensional array of leaf-shaped bowtie antenna with flat reflector for further improvement of the antenna gain. The array spacing and the separation between a dielectric substrate and a reflector are designed for achieving the widest -3dB gain bandwidth. The antenna characteristics such as reflection, actual gain, transmission and group delay are revealed by measurements and FDTD analysis. From calculations of cros...
  • AMEYA Michitaka, ITO Yoshinori, YAMAMOTO Manabu, NOJIMA Toshio
    IEICE technical report. Antennas and propagation 一般社団法人電子情報通信学会 107 (144) 1 - 5 0913-5685 2007/07 [Not refereed][Not invited]
     
    We have previously proposed a unidirectional leaf-shaped bowie antenna for UWB application and investigated the characteristics of the antenna. In Japan, the available frequency bandwidth for UWB systems are narrower than that approved by FCC. In this paper, we discuss the waveform distortions caused by the unidirectional leaf-shaped bowtie antenna when the pulse waveform fitted in ARIB UWB spectrum mask is used as template pulses.
  • A. Y. Simba, M. Yamamoto, T. Nojima, K. Itoh
    IET MICROWAVES ANTENNAS & PROPAGATION 1 (3) 658 - 665 1751-8725 2007/06 [Refereed][Not invited]
     
    The authors propose a design of a circularly polarised proximity-fed microstrip antenna having polarisation switching ability. The proposed antenna has a simple structure, consisting of a truncated-comers square patch in the same plane with a microstrip feed line extended beyond the patch edge, pin diode and a pad connected to a ground by a conducting post. The diode, which is inserted between the end of the feed line and a pad, is used to control feed line termination. By turning the diode on or off, this antenna can radiate either right hand or left hand circular polarisation. Furthermore, we present a technique to improve the input characteristics of the antenna. It involves two diode-controlled tuning stubs connected in shunt with the feed line. Finally, a discussion on how the diode characteristics affect the structure and results of the antenna is given. All analyses are carried out using finite-difference time-domain technique and confirmed by measurements in the 5 GHz band. A good agreement between the simulated and measured results was obtained.
  • ITO Yoshinori, AMEYA Michitaka, YAMAMOTO Manabu, NOJIMA Toshio
    Proceedings of the IEICE General Conference 一般社団法人電子情報通信学会 2007 (1) 152 - 152 2007/03 [Not refereed][Not invited]
  • AMEYA Michitaka, YAMAMOTO Manabu, NOJIMA Toshio
    Proceedings of the IEICE General Conference 一般社団法人電子情報通信学会 2007 (1) 151 - 151 2007/03 [Not refereed][Not invited]
  • Michitaka Ameya, Yoshinori Ito, Manabu Yamamoto, Toshio Nojima
    2007 IEEE ANTENNAS AND PROPAGATION SOCIETY INTERNATIONAL SYMPOSIUM, VOLS 1-12 (2A4-1) 1803 - 1806 1522-3965 2007 [Refereed][Not invited]
  • Michitaka Ameya, Yoshinori Ito, Manabu Yamamoto, Toshio Nojima
    2007 IEEE ANTENNAS AND PROPAGATION SOCIETY INTERNATIONAL SYMPOSIUM, VOLS 1-12 (208.2) 1803 - 1806 1522-3965 2007 [Refereed][Not invited]
  • SAITO Yuta, YAMAMOTO Manabu, NOJIMA Toshio
    IEICE technical report. Antennas and propagation 一般社団法人電子情報通信学会 106 (416) 59 - 62 0913-5685 2006/12 [Not refereed][Not invited]
     
    In this report, we evaluate characteristics of the mobile handset dipole antenna with unbalanced feed in the vicinity of human phantom model by performing FDTD analysis. Based on the results obtained by the analysis, the influence of the slits cut on the ground plane on the antenna characteristics is investigated. From the FDTD results, it is found that the current induced on the ground plane is significantly reduced with the slits on the ground plane. For this case, 20% increase in radiation efficiency is confirmed.
  • AMEYA Michitaka, YAMAMOTO Manabu, NOJIMA Toshio, ITOH Kiyohiko
    Proceedings of the Society Conference of IEICE 一般社団法人電子情報通信学会 2006 (1) "S - 9"-"S-10" 2006/09 [Not refereed][Not invited]
  • SAITO Yuta, YAMAMOTO Manabu, NOJIMA Toshio
    Proceedings of the Society Conference of IEICE 一般社団法人電子情報通信学会 2006 (1) 142 - 142 2006/09 [Not refereed][Not invited]
  • AMEYA Michitaka, YAMAMOTO Manabu, NOJIMA Toshio, ITO 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 89 (9) 1820 - 1823 1344-4697 2006/09 [Refereed][Not invited]
     
    筆者らは過去にUWB用自己補対プリントダイポールアンテナを提案したが,その放射特性は周波数により変化する問題があった.本論文では上記アンテナについて,ある基準値を超える動作利得が確保される周波数を下限周波数として決定するという設計指針に基づいて再設計を行った.その結果,放射特性の周波数依存性が改善されることを実験的に確認した.
  • ISHIGAKI Takahiro, YAMAMOTO Manabu, NOJIMA Toshio, ITO 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 89 (9) 1688 - 1695 1344-4697 2006/09 [Refereed][Not invited]
     
    マイクロストリップ線路の両側にプリントスロットが配置された45度直線偏波アレーアンテナを設計し,その諸特性を明らかにする.はじめに,マイクロストリップ線路と,線路に対して45度の角度で線路の両側に配置された2素子のスロットとの結合量を求める.この結果に基づき,16素子アレーを設計するとともに,モーメント法解析並びに実験によりその特性を評価し,設計の妥当性を確認する.更に,背面放射を抑制し,利得の向上を図るために,アンテナ背面に反射板を設置した場合の諸特性を示す.
  • An Omnidirectional UWB Printed Dipole Antenna with Small Waveform Distortion
    ichitaka Ameya, Manabu Yamamoto, Toshio Nojima
    Proc. of Progress In Electromagnetics Research Symposium 2006 (4P3) 515  2006/08 [Refereed][Not invited]
  • AMEYA Michitaka, YAMAMOTO Manabu, NOJIMA Toshio, ITOH Kiyohiko
    IEICE technical report. Antennas and propagation 一般社団法人電子情報通信学会 106 (140) 31 - 36 0913-5685 2006/06 [Not refereed][Not invited]
     
    We have proposed a UWB printed dipole antenna using self-complementary radiating elements. When the antenna is attached to walls or metal surfaces, the characteristics of the antenna can deteriorate because it has omnidirectional radiation patterns. In this paper, in order to avoid the degradation due to the omnidiractionality, we attempt to realize unidirectional radiation patterns by using a flat reflector. The distance between the antenna and the reflector is designed for achieving the widest -3dB gain bandwidth. The antenna characteristics such as reflection, realized gain, transmission...
  • SAITO Yuta, YAMAMOTO Manabu, NOJIMA Toshio
    Proceedings of the IEICE General Conference 一般社団法人電子情報通信学会 2006 (1) 129 - 129 2006/03 [Not refereed][Not invited]
  • AMEYA Michitaka, YAMAMOTO Manabu, NOJIMA Toshio, ITOH Kiyohiko
    Proceedings of the IEICE General Conference 一般社団法人電子情報通信学会 2006 (1) 103 - 103 2006/03 [Not refereed][Not invited]
  • AMEYA Michitaka, YAMAMOTO Manabu, NOJIMA Toshio, ITOH Kiyohiko
    IEICE technical report. Antennas and propagation 一般社団法人電子情報通信学会 105 (561) 89 - 92 0913-5685 2006/01 [Not refereed][Not invited]
     
    In impulse-based UWB communications, if coherent detection is used as the demodulation scheme, wave distortions of transmitted and received pulses caused by antennas induce degradations of the communication performance. In order to avoid these effects, it is necessary that radiation characteristics of the antenna be constant over the wide frequency range. Self-complementary UWB printed dipole antenna that we have proposed has the problem of frequency dependent radiation characteristics. In this paper, we propose design guidelines for reducing the frequency dependency of radiation characteri...
  • M Ameya, M Yamamoto, T Nojima, K Ito
    ELECTRONICS AND COMMUNICATIONS IN JAPAN PART I-COMMUNICATIONS 89 (12) 62 - 74 8756-6621 2006 [Refereed][Not invited]
     
    In UWB wireless communications systems, communication is performed with frequency resources covering several gigahertz. Therefore, antennas with broadband characteristics are required. In this paper, a planar broadband antenna consisting of a self-complementary radiating element and a tapered, microstrip line is proposed. First, FDTD analyses are performed for a printed dipole antenna consisting of self-complementary radiating elements of diamond shape, fan shape, and bowtie shape. It is shown that the diamond-shaped radiating element is advantageous for size reduction. Next, a design guideline for the printed dipole antenna combining a tapered microstrip line with a self-complementary radiating element is investigated. Based on the results of the investigation, an antenna that covers the UWB frequencies (3.1 to 10.6 GHz) approved by the FCC is designed and fabricated. Its characteristics are experimentally evaluated for confirmation of the effectiveness of the proposed antenna. (c) 2006 Wiley Periodicals, Inc.
  • AY Simba, M Yamamoto, T Nojima, K Itoh
    IEE PROCEEDINGS-MICROWAVES ANTENNAS AND PROPAGATION 152 (5) 347 - 353 1350-2417 2005/10 [Refereed][Not invited]
     
    The authors present a novel planar-type sectored antenna construction useful for broadband wireless communication systems. The proposed configuration is based on a slot Yagi-Uda array integrated on a dielectric substrate, which is suitable for mass-production at low cost. First, the slot Yagi-Uda array is analysed using the finite-difference time-domain (FDTD) technique. In order to obtain the data for the design of the planar-type sectored antenna, the radiation characteristics and return loss of the array are evaluated as a function of the number of directors. Next, based on the results obtained, a 6-sector antenna is designed by employing a 4-element slot Yagi-Uda array, and its performance is investigated with FDTD analysis and experiments. The mutual coupling between the neighbouring sectors is found to be less than -38 dB, and the radiation pattern that can cover the entire azimuth direction with a crossover depth of -3 dB is obtained.
  • AY Simba, M Yamamoto, T Nojima, K Itoh
    IEE PROCEEDINGS-MICROWAVES ANTENNAS AND PROPAGATION 152 (5) 331 - 336 1350-2417 2005/10 [Refereed][Not invited]
     
    The gains of tapered dielectric rod antennas are determined primarily by their length. However, long tapered rods are difficult to realise and arrays of these antennas are needed if much higher gain is required. In the paper, a linear array of dielectric rod antennas is proposed based on an image NRD guide which employs a slotted rectangular waveguide feed. This array demonstrates the ability to achieve high gain in a simple structure with relatively short tapered rods. First, a single-element dielectric rod antenna is analysed using the FDTD technique to obtain the data for the design of the linear array. Based on the results obtained, the 2-element linear array is designed and analysed. A gain of 22dB is obtained by the 2-element array using the antenna length of 90mm (10.6 lambda(o)). This gain requires an antenna length of about 200 mm (23.51 lambda(o)) if conventional rod antennas were to be used. Measured results are presented to confirm the effective performance of the proposed array configuration.
  • AMEYA Michitaka, YAMAMOTO Manabu, NOJIMA Toshio, ITO Kiyohiko
    Proceedings of the Society Conference of IEICE 一般社団法人電子情報通信学会 2005 (1) 160 - 160 2005/09 [Not refereed][Not invited]
  • ISHIGAKI Takahiro, YAMAMOTO Manabu, NOJIMA Toshio, ITOH Kiyohiko
    Proceedings of the Society Conference of IEICE 一般社団法人電子情報通信学会 2005 (1) 98 - 98 2005/09 [Not refereed][Not invited]
  • AMEYA Michitaka, YAMAMOTO Manabu, NOJIMA Toshio, ITO 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 88 (9) 1662 - 1673 1344-4697 2005/09 [Refereed][Not invited]
     
    UWB無線システムでは, 数GHzにわたる帯域の周波数資源を用いて通信が行われるため, 広帯域な特性を有するアンテナが要求される.本論文では, 自己補対型の放射素子とテーパ形のマイクロストリップ線路で構成される平面型の広帯域アンテナを提案する.はじめに, 菱形, 扇形及びボウタイ形の自己補対放射素子からなるプリントダイポールアンテナのFDTD解析を行い, 菱形の放射素子が小型化に有利であることを示す.次に, 自己補対放射素子にテーパ形のマイクロストリップ線路を組み合わせたプリントダイポールアンテナの設計指針について考察する.その結果を踏まえて, FCC認可のUWB用周波数(3.1〜10.6GHz)をカバーするアンテナを設計・試作するとともに, その特性を実験的に評価することにより, 提案アンテナの有効性を確認している.
  • 45-Degrees Linearly Polarized Array Antenna Consisting of Printed Slots Arranged in Both Sides of Microstrip Line
    Takahiro Ishigaki, Manabu Yamamoto, Toshio Nojima, Kiyohiko Itoh
    Proc. of 2005 International Symposium on Antennas and Propagation 3 (FA4-6) 993 - 996 2005/08 [Refereed][Not invited]
  • Ally Yahaya Simba, Manabu Yamamoto, Toshio Nojima, Kiyohiko Itoh
    Proc. of 2005 International Symposium on Antennas and Propagation 3 (FA4-3) 985 - 988 2005/08 [Refereed][Not invited]
  • Michitaka Ameya, Manabu Yamamoto, Toshio Nojima, Kiyohiko Itoh
    Proc. of 2005 International Symposium on Antennas and Propagation 1 (WB3-6) 137 - 140 2005/08 [Refereed][Not invited]
  • SIMBA Ally Yahaya, YAMAMOTO Manabu, Nojima Toshio, ITOH Kiyohiko
    IEICE technical report. Antennas and propagation 一般社団法人電子情報通信学会 105 (188) 15 - 20 0913-5685 2005/07 [Not refereed][Not invited]
     
    This paper presents a design of circularly polarized proximity-fed microstrip antenna with switchable polarization sense. The designed antenna consists of a truncated-corners square patch, microstrip line feed extended beyond the patch edge, pin diode and a pad connected to the ground by a conducting post. The diode, which is inserted between the end of feed line and the pad, is used to control the termination of the feed line. By turning the diode on or off, this antenna can radiate with either right hand or left hand circular polarization. Further more, a technique to improve input charac...
  • A Study of Microstrip Dipole Antenna Having Ultra-Wideband Characteristics
    Michitaka Ameya, Manabu Yamamoto, Toshio Nojima, Kiyohiko Itoh
    2004 Korea-Japan Joint Conference Proceedings (AP-3-11) 45 - 48 2004/11 [Refereed][Not invited]
  • ISHIGAKI Takahiro, YAMAMOTO Manabu, NOJIMA Toshio, ITOH Kiyohiko
    IEICE technical report. Antennas and propagation 一般社団法人電子情報通信学会 104 (395) 37 - 42 0913-5685 2004/10 [Not refereed][Not invited]
     
    A 45-degree linearly polarized array antenna in which printed slots are arranged on both sides of a microstrip line is designed, and its characteristics are revealed. First, the coupling level between a microstrip line and a pair of slots arranged on both sides of feedline is evaluated. Based on this result, a 16-element slot array is designed, and its characteristics are investigated by the moment method analysis and measurements in order to confirm the effective performance of the antenna. In addition, characteristics of the array antenna, in which a backing reflector is introduced for th...
  • A. Y. Simba, M. Yamamoto, T. Nojima, K. Itoh
    IEE Proceedings: Microwaves, Antennas and Propagation 151 (5) 404 - 408 1350-2417 2004/10 [Refereed][Not invited]
     
    A broadside linear array of a resonant-type leaky-wave antenna with a new construction based on an image nonradiating dielectric (NRD) guide is proposed. Fundamental characteristics are investigated by performing both the finite-difference time-domain (FDTD) analysis and basic experiments. The proposed configuration makes it possible to improve the H-plane pattern beamwidth, which is much wider than that of the E-plane. First, a single-element resonant-type leaky-wave antenna fed by a longitudinal slot on the broad wall of a rectangular waveguide is analysed to obtain the data used for the design of the linear array. Next, based on the results obtained, a 2-element linear array employing the same feeding technique as that of the single-element case is designed and analysed. The H-plane beamwidth is found to be 34°, which is 36°narrower than that of the single-element antenna. Finally, measured results are also presented to confirm the effective performance of the proposed configuration. © IEE, 2004.
  • AY Simba, M Yamamoto, T Nojima, K Itoh
    IEICE TRANSACTIONS ON ELECTRONICS E87C (9) 1405 - 1411 0916-8524 2004/09 [Refereed][Not invited]
     
    An image NRD guide-fed dielectric rod antenna, which is suitable for use at millimeter-wave frequencies, is presented in this paper. The antenna is composed of a linearly tapered dielectric rod connected to the image NRD guide. First, radiation characteristics of the dielectric rod antenna directly protruded from the end of the image NRD guide are investigated by FDTD analysis and measurements at 30 GHz band. For this case, the degradation of the radiation pattern and the decrease of the gain, which are due to the strong radiation from the guide-to-antenna discontinuity, are observed. In order to minimize this radiation and to realize reasonable radiation characteristics, a transition from the image NRD guide-to-rod antenna is proposed. A simple procedure to determine the optimum dimensions of the transition is described. This procedure is based on parametric study of the transition's dimensions, and is performed using FDTD analysis. Based on the results, the dielectric rod antenna having a length of 10 10 is designed, and its performance is analyzed and measured. The results show that radiation patterns with the half power beamwidth of 22degrees, sidelobe level of -21 dB and reasonable gain of 18.5 dBi can be realized by employing the transition having the optimum dimensions.
  • Polarization Switchable Microstrip Array Antenna Based on Proximity Feeding Technique
    Manabu Yamamoto, Taisuke Tokunaga, Toshio Nojima, Kiyohiko Itoh
    Proc. of 2004 International Symposium on Antennas and Propagation 1 (2B4-3) 413 - 416 2004/08 [Refereed][Not invited]
  • SIMBA Ally Yahaya, YAMAMOTO Manabu, Nojima Toshio, ITOH Kiyohiko
    IEICE technical report. Antennas and propagation 一般社団法人電子情報通信学会 104 (203) 81 - 86 0913-5685 2004/07 [Not refereed][Not invited]
     
    A circularly polarized proximity-fed microstrip antenna (CP-PMA) is presented, and its performance is evaluated in this report. The CP-PMA consists of a truncated-corners square patch coupled in close proximity to a microstrip line. Firstly, fundamental characteristics of the single-element CP-PMA are investigated by FDTD analysis and experiments at 5GHz band. From the obtained results, it is verified that the sense of the polarization can be switched by adjusting the length of the feedline beyond the patch edge. Secondly, 2-element CP-PMA array is designed, and its performance is presented.
  • AMEYA Michitaka, YAMAMOTO Manabu, Nojima Toshio, ITOH Kiyohiko
    IEICE technical report. Antennas and propagation 一般社団法人電子情報通信学会 104 (203) 75 - 80 0913-5685 2004/07 [Not refereed][Not invited]
     
    Broadbanding techniques for microstrip dipole antennas are discussed in this report. Firstly, we propose a planar-type dipole antenna printed on a dielectric substrate. The antenna is composed of self-complementary radiating elements and a microstrip line. Fundamental characteristics of the proposed antenna are evaluated by FDTD analysis and measurements. It is verified that bandwidth of VSWR ≤ 2 and relatively omni-directional radiation in the azimuth plane can be achieved over the FCC approved UWB frequency range of 3.1 to 10.6GHz. Measured transmission characteristics of the antenna a...
  • YAMAMOTO Manabu, TOKUNAGA Taisuke, NOJIMA Toshio, ITOH Kiyohiko
    Proceedings of the IEICE General Conference 一般社団法人電子情報通信学会 2004 (1) 193 - 193 2004/03 [Not refereed][Not invited]
  • AMEYA Michitaka, YAMAMOTO Manabu, NOJIMA Toshio, ITOH Kiyohiko
    Proceedings of the IEICE General Conference 一般社団法人電子情報通信学会 2004 (1) 139 - 139 2004/03 [Not refereed][Not invited]
  • Hiraga Ken, Yamamoto Manabu, Nojima Toshio
    Proceedings of the IEICE General Conference 一般社団法人電子情報通信学会 2004 (1) 71 - 71 2004/03 [Not refereed][Not invited]
  • M Katayama, M Yamamoto, T Nojima, K Itoh
    ELECTRONICS LETTERS 40 (4) 223 - 224 0013-5194 2004/02 [Refereed][Not invited]
     
    A microstrip-fed crossed-slot array antenna having a circular polarisation is developed. First, a single crossed-slot antenna, that can radiate a circularly polarised wave in the broadside direction, is designed an its coupling level to the microstrip line is analysed. Based on this result, an eight-element crossed-slot array is designed and its characteristics are experimentally investigated at 12 GHz band. The return loss of -17 dB is obtained at the design frequency of 11.85 GHz, and the axial ratio of less than 3 dB is achieved over the fractional bandwidth of 5%.
  • H Saito, T Nishimura, M Yamamoto, K Itoh
    ELECTRONICS AND COMMUNICATIONS IN JAPAN PART I-COMMUNICATIONS 87 (4) 45 - 53 8756-6621 2004 [Refereed][Not invited]
     
    The quasi-optical antenna-mixer is a receiving system that spatially receives RF signals and local oscillator (LO) signals and at the same time converts the RF signals to intermediate (IF) frequency signals. The line transmission loss, which causes a problem at millimeter wave frequencies, can be suppressed. In this paper, test fabrication and measurement of a quasi-optical antenna-mixer array receiving RF and LO signals with a magnetic loop antenna are carried out at 10 GHz and quasi-optical mixing is shown to be possible. A two-dimensional array antenna using this element is proposed. Its receiving characteristics are theoretically predicted. By changing the illumination angle or frequency of the LO, it is found that the receiving direction of the RF can be scanned. In addition, the suppression of RF and LO signals appearing at the output end is demonstrated. An experiment with a two-dimensional array consisting of eight elements of quasi-optical antenna-mixers is carried out and the validity of the proposal is confirmed. (C) 2003 Wiley Periodicals, Inc.
  • Image NRD Guide-fed Dielectric Rod Antenna Array
    Ally Yahaya Simba, Manabu Yamamoto, Toshio Nojima, Kiyohiko Itoh
    2003 Asia-Pacific Microwave Conference 3 (FB4) 1608 - 1611 2003/11 [Refereed][Not invited]
  • A Printed Slot Array Antenna Having 45-Degrees Linear Polarization
    Manabu Yamamoto, Masahiko Katayama, Toshio Nojima, Kiyohiko Itoh
    2003 Asia-Pacific Microwave Conference 2 (TD3) 1056 - 1059 2003/11 [Refereed][Not invited]
  • M Katayama, M Yamamoto, T Nojima, K Itoh
    ELECTRONICS LETTERS 39 (21) 1492 - 1493 0013-5194 2003/10 [Refereed][Not invited]
     
    A 45degrees inclined linearly polarised slot array antenna with microstrip line feed has been developed. To simplify the feed system, series feeding is adopted to excite the radiating slots. An eight-element slot array, with an operating frequency that is of 12 GHz band, has been designed and its characteristics are investigated by the moment method analysis. Measured results are also presented to validate the numerical evaluations.
  • Tokunaga, I, M Yamamoto, Nojima, I, K Itoh
    ELECTRONICS LETTERS 39 (22) 1569 - 1570 0013-5194 2003/10 [Refereed][Not invited]
     
    A polarisation switchable microstrip array antenna is presented. This array consists of square patch antennas coupled in close proximity to a microstrip line. The polarisation state can be switched electrically by short- or open-circuiting the end of the feedline using a PIN diode. Fundamental characteristics of the proposed array are investigated by measurements performed at S-band to demonstrate the proposal.
  • YAMAMOTO Manabu, KATAYAMA Masahiko, NOJIMA Toshio, ITOH Kiyohiko
    Proceedings of the Society Conference of IEICE 一般社団法人電子情報通信学会 2003 (1) 207 - 207 2003/09 [Not refereed][Not invited]
  • TOKUNAGA Taisuke, YAMAMOTO Manabu, NOJIMA Toshio, ITOH Kiyohiko
    IEICE technical report. Antennas and propagation 一般社団法人電子情報通信学会 103 (230) 91 - 96 0913-5685 2003/07 [Not refereed][Not invited]
     
    A Proximity fed Microstrip Antenna (PMA), in which a microstrip element is excited by a microstrip feed line via a narrow gap, is known to have advantages such that the polarization plane can be switched. In this report, a configuration of 2-element PMA array is proposed, and its fundamental characteristics are investigated by FDTD analysis and experiments. A circuit for controlling the polarization status electronically is proposed, and its effective performance are revealed bv measurements.
  • KATAYAMA Masahiko, YAMAMOTO Manabu, NOJIMA Toshio, ITOH Kiyohiko
    IEICE technical report. Antennas and propagation 一般社団法人電子情報通信学会 103 (230) 79 - 84 0913-5685 2003/07 [Not refereed][Not invited]
     
    A 45-degree linearly polarized slot array with microstrip line feed is developed. In order to simplify the feed system and to reduce the feeding line loss, series feeding is adopted to excite the radiating slots. First, the coupling level between the single slot and the microstrip line is evaluated. Based on this result, a one-dimensional eight-slot array is designed and its characteristics are numerically investigated. Using four sets of the 8-slot array and a backing reflector, a two-dimensional array is constructed and its effective performance is demonstrated by the analysis. Measured r...
  • SA Yahaya, M Yamamoto, K Itoh, T Nojima
    ELECTRONICS LETTERS 39 (15) 1099 - 1101 0013-5194 2003/07 [Refereed][Not invited]
     
    A dielectric rod antenna based on an image NRD guide fed by a slot in the broad wall of a rectangular waveguide is proposed. This configuration is developed for the use in the design of an array of this antenna. The antenna characteristics are investigated using the finite difference time domain (FDTD) technique. Measured results at 30 GHz band are presented to validate the numerical analysis.
  • Novel Planar-Type Sectored Antenna Consisting of a Slot Yagi-Uda Array with Post-Wall Cavity
    M. Yamamoto, N. Kobayashi, K. Itoh, T. Nojima
    Proceedings of 2003 IEEE International Antennas and Propagation Symposium (59.7) 2003/06 [Refereed][Not invited]
  • YAMAMOTO Manabu, TOKUNAGA Taisuke, NOJIMA Toshio, ITOH Kiyohiko
    Proceedings of the IEICE General Conference 一般社団法人電子情報通信学会 2003 (1) 250 - 250 2003/03 [Not refereed][Not invited]
  • Linear Array of Resonant-Type Leaky-Wave Antenna Based on Image NRD Guide
    Simba Ally Yahaya, Manabu Yamamoto, Kiyohiko Itoh, Toshio Nojima
    Proceedings of the 2002 Interim International Symposium on Antennas and Propagation 149 - 152 2002/11 [Refereed][Not invited]
  • Dielectric Rod Antenna fed by Image NRD Guide
    Manabu Yamamoto, Toshio Nojima, Kiyohiko Itoh
    Proceedings of the 2002 Interim International Symposium on Antennas and Propagation 125 - 128 2002/11 [Refereed][Not invited]
  • Dielectric Rod Antenna Based on Image NRD Guide
    Manabu Yamamoto, Toshio Nojima, Kiyohiko Itoh
    2002 Asia-Pacific Microwave Conference Proceedings 2 1260 - 1263 2002/11 [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 85 (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.
  • SAITO Hiroyuki, NISHIMURA Toshihiko, YAMAMOTO 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 85 (9) 1493 - 1500 1344-4697 2002/09 [Refereed][Not invited]
     
    準光学アンテナ・ミキサは,高周波信号(RF)と局部発振周波(LO)の信号を空間的に受信すると同時に中間周波数(IF)信号へ変換する受信システムであり,ミリ波帯で問題となる線路の伝送損失をおさえることができる.本論文では,RFとLOを磁流ループアンテナで受信する準光学アンテナ・ミキサアレーの10GHz帯における試作測定を行い,準光学的ミキシングが可能であることを示す.また,この素子を用いた2次元アレーアンテナを提案し,理論的にその受信特性を明らかにする.LOの照射角または周波数を変えることでRFの受信方向が走査できることに加えて,出力端にろうえいするRF・LO信号の抑制が可能であることを示す.8素子の準光学アンテナ・ミキサで構成される2次元アレーの実験を行い,提案の妥当性を確認する.
  • NAITO Takashi, YAMAMOTO Manabu, NOJIMA Toshio, ITOH Kiyohiko
    IEICE technical report. Antennas and propagation 一般社団法人電子情報通信学会 102 (232) 19 - 24 0913-5685 2002/07 [Not refereed][Not invited]
     
    In broadband wireless communications such as WLANs, degradation of transmission quality due to the multipath propagation is a serious problem. A multi-sector antenna is useful to compensate the multipath interference. The authors have previously proposed a planar-type multi-sector antenna consisting of a slot array with backward excitation, and have clarified its characteristics with measurements. To confirm these results numerically, the moment method analysis of the sector-antenna mentioned above is carried out in this report. Procedures to evaluate the mutual coupling between the adjacen...
  • KOBAYASHI Naoki, YAMAMOTO Manabu, NOJIMA Toshio, ITOH Kiyohiko
    IEICE technical report. Antennas and propagation 一般社団法人電子情報通信学会 102 (232) 13 - 18 0913-5685 2002/07 [Not refereed][Not invited]
     
    In broadband wireless communications such as WLANs, degradation of transmission quality due to the multipath propagation is a serious problem. A multi-sector antenna is useful to compensate the multipath interference, and have been studied in many literatures. From the viewpoints of mass producibility and ease of installation, it is preferable to introduce a multi-sector antenna having a planar configuration. To meet these requirements, a planar-type multi-sector antenna consisting of a slot Yagi-Uda array with post-wall cavity is proposed in this report. First, characteristics of the singl...
  • M Yamamoto, K Ishizaki, M Muramoto, K Sasaki, K Itoh
    ELECTRONICS AND COMMUNICATIONS IN JAPAN PART I-COMMUNICATIONS 85 (11) 68 - 76 8756-6621 2002 [Refereed][Not invited]
     
    The slot array antenna with backward excitation is promising as a constituent element of a planar multisector antenna. This paper deals with a slot array antenna with backward excitation that prevents radiation into the backside by installing a cavity. With a view to simplifying the fabrication process, all slots in the array share one cavity. A design guideline is discussed for reducing mutual coupling between the elements. It is found that the cavity width should cause the TE10 mode to be cut off. For a four-element array with a cavity satisfying this condition, the characteristics are evaluated by the spectral domain moment method. It is shown that a beam tilt toward the end fire direction can be obtained, similarly to the case without a cavity. The antenna characteristics are evaluated in terms of cavity length and depth. It is demonstrated that the effect of the cavity length on the antenna characteristics is significant and that the cavity thickness can be reduced. Further, a test experiment is conducted at 19 GHz to confirm the validity of the numerical study. (C) 2002 Wiley Periodicals, Inc.
  • M Yamamoto, K Ishizaki, M Muramoto, K Sasaki, K Itoh
    ELECTRONICS AND COMMUNICATIONS IN JAPAN PART I-COMMUNICATIONS 85 (9) 59 - 68 8756-6621 2002 [Refereed][Not invited]
     
    Attention is directed to the slot array antenna that is serially fed by a microstrip line and a method is studied for using this antenna as a constituent element of a planar multisector antenna for wireless LAN. Based on the design ignoring the mutual coupling between the slots, an excitation method for realization of a beam tilt toward the endfire direction is investigated. It is found that backward excitation is effective. The antenna is modeled by the spectral domain moment method and a design is carried out by taking into account the mutual coupling. Further, by test measurement, the validity of the modeling and the effectiveness of the proposed design method are confirmed. (C) 2002 Wiley Periodicals, Inc.
  • LC Chirwa, K Morimoto, Y Sugawara, M Yamamoto, M Omiya, K Itoh
    ELECTRONICS AND COMMUNICATIONS IN JAPAN PART I-COMMUNICATIONS 85 (5) 25 - 33 8756-6621 2002 [Refereed][Not invited]
     
    A transverse slot placed in the image plane of the image NRD guide that has a low loss nature similar to that of the NRD guide in a millimeter wave circuit can be designed using waveguide array theory. In this paper, a method is presented to derive the normalized impedance of the transverse slot needed for the design from standing wave measurement. Near the slot, the standing wave distribution is disturbed by the field scattered from the slot. A method is given to derive the minimum distance for which no effect of the scattered field is received. From the standing wave distribution in the range where this condition is satisfied, the normalized impedance is evaluated. Further, in order to determine the validity and effectiveness of the evaluation method, an analysis based on the finite difference time domain (FDTD) method is carried out and the results are compared with the experimental data. Finally, a design example of an array antenna is presented. A possibility for applications of the proposed measurement method and the derived normalized impedance to the array antenna design is confirmed. (C) 2002 Scripta Technica.
  • KAMIKAWA Tomohiko, YAMAMOTO Manabu, ITOH Kiyohiko
    Proceedings of the Society Conference of IEICE 一般社団法人電子情報通信学会 2001 (1) 167 - 167 2001/08 [Not refereed][Not invited]
  • YAMAMOTO Manabu, KOBAYASHI Naoki, ITOH Kiyohiko
    Proceedings of the Society Conference of IEICE 一般社団法人電子情報通信学会 2001 (1) 165 - 165 2001/08 [Not refereed][Not invited]
  • Yamamoto Manabu, Takai Ryoh, Itoh Kiyohiko
    IEICE technical report. Antennas and propagation 一般社団法人電子情報通信学会 101 (231) 97 - 104 0913-5685 2001/07 [Not refereed][Not invited]
     
    In General, main beam direction of leaky-wave antennas is not broadside because of the traveling wave type source distribution. A resonant-type leaky wave antenna based on an Image NRD guide, which was previously proposed by the authors, poses a standing wave type source distribution. This feature results in the broadside radiation with low side lobe level and high directivity. In this report, we perform FDTD analysis of the resonant-type leaky wave antenna with waveguide feed to verify the operation principle of the antenna. Using the FDTD results, we also clarify the variation of the refl...
  • SAITO Hiroyuki, NISHIMURA Toshihiko, YAMAMOTO Manabu, ITOH Kiyohiko
    IEICE technical report. Antennas and propagation 一般社団法人電子情報通信学会 101 (231) 89 - 96 0913-5685 2001/07 [Not refereed][Not invited]
     
    The quasi-optical antenna mixer system transforms RF signal into intermediate frequency signal as soon as the system receives the RF signal and local oscillator's signal spatially. Using this system, we can reduce transmission loss, which causes serious problem in the millimeter-wave band. A simple Quasi-Optical Antenna-Mixer (QOAM) have been proposed using a magnetic loop antenna in our former study, and we have confirmed experimentally the performance of beam scanning with the arrayed QOAM in the 3GHz-band. In this report, we explore possibility for our proposal of application in the high...
  • LC Chirwa, M Yamamoto, M Omiya, K Itoh
    IEEE TRANSACTIONS ON MICROWAVE THEORY AND TECHNIQUES 49 (5) 995 - 997 0018-9480 2001/05 [Refereed][Not invited]
     
    This paper presents a method for determining the normalized impedance of a transverse slot in the image plane of the image nonradiative dielectric guide using measurements of the standing wave. The method overcomes the problem of distortion caused by the scattered evanescent fields that are present in the vicinity of the slot. The measurement equipment, its optimum parameters, and aspects necessary for accurate measurements are also discussed, Moreover, the finite-difference time-domain technique is employed to determine the normalized dot impedance, and good agreement is obtained with measured results, confirming the reliability of the method.
  • M Yamamoto, K Ozaki, K Itoh
    ELECTRONICS AND COMMUNICATIONS IN JAPAN PART I-COMMUNICATIONS 84 (5) 31 - 39 8756-6621 2001/05 [Refereed][Not invited]
     
    In the Triplate line fed Slot-Coupled Patch Antenna (TSCPA), the generation of the parallel plate mode becomes a minimum at the resonant frequency of the radiating patch. However, the resistive part of the input impedance (input resistance) at this frequency is extremely low. In this paper, a method is proposed to raise the input resistance at the resonant frequency of the patch. By means of the equivalent circuit of the TSCPA, it is made clear that the input resistance at the resonant frequency of the patch is reduced due to the inductive effect of the slot. A design guideline for the slot is discussed for relaxing the reduction of the input resistance due to the inductive effect. Further, it is shown that the input resistance can be increased by placing a strip shorter than the resonant length between the patch and the slot so that the inductive effect can be canceled. (C) 2001 Scripta Technica, Electron Comm Jpn Pt 1, 84(5):31-39,2001.
  • YAMAMOTO Manabu, OSAKABE Taro, ITOH Kiyohiko
    Proceedings of the IEICE General Conference 一般社団法人電子情報通信学会 2001 (1) 225 - 225 2001/03 [Not refereed][Not invited]
  • T Kaichida, N Ishii, M Yamamoto, T Nishimura, K Itoh
    ELECTRONICS AND COMMUNICATIONS IN JAPAN PART I-COMMUNICATIONS 84 (3) 21 - 28 8756-6621 2001/03 [Refereed][Not invited]
     
    At millimeter wave frequencies, the loss in the transmission line is significant. To alleviate this problem, a quasi-optical mixer will reduce the transmission loss by combining the antenna and the mixer. The RF and the local signals at two different frequencies are received spatially, and the intermediate frequency is generated immediately. To realize this function, there is a microstrip antenna fed by a coplanar waveguide to operate at two frequencies. In this paper, the spectral domain method is used to analyze the input characteristics of the 1/20 scale model of this antenna at microwave frequencies. It is shown that the antenna can be operated at two frequencies independently. Further, the radiation characteristics of this antenna are evaluated in terms of the absolute gain. (C) 2000 Scripta Technica.
  • K Hattori, M Yamamoto, K Itoh
    ELECTRONICS AND COMMUNICATIONS IN JAPAN PART II-ELECTRONICS 84 (10) 9 - 16 8756-663X 2001 [Refereed][Not invited]
     
    The image NRD guide as a modification of the NRD guide is expected to find applications at millimeter wave frequencies. In order to construct circuits and antennas containing image NRD guides and to evaluate their characteristics, a transition to another waveguide is needed. In this paper, a transition structure from a rectangular waveguide to an image NRD is proposed and its operating principle is explained. Also, by means of numerical calculations based on the effective dielectric constant (EDC) method, a transition intended for use in the R band (30 GHz) is designed. Further, the designed transition is measured and the effectiveness of the proposed transition is demonstrated. (C) 2001 Scripta Technica.
  • YAMAMOTO Manabu, ISHIZAKI Kosuke, MURAMOTO Mitsuru, SASAKI Kanemi, 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 83 (12) 1730 - 1738 1344-4697 2000/12 [Refereed][Not invited]
     
    バックワード励振スロットアレーアンテナは, 平面マルチセクタアンテナの構成要素として有望である.本論文では, キャビティを装着し, 背面への放射をおさえたバックワード励振スロットアレーアンテナを取り扱う.製作工程の簡略化を目的として, アレーを構成するすべてのスロットが一つのキャビティを共有する構造を提案している.キャビティを介した素子間相互結合をおさえるための設計指針について検討し, TE_<10>モードがカットオフとなるキャビティ幅とすればよいことを示している.この条件を満たすキャビティを付加した4素子アレーアンテナについて, スペクトル領域モーメント法による特性評価を行い, キャビティなしの場合と同様に, エンドファイア方向へのビームチルトが得られることを示している.また, キャビティの長さと深さをパラメータとしたアンテナ特性の評価を行い, キャビティ長さの変化がアンテナ特性に与える影響は極めて小さいことと, キャビティの薄型化が可能なことを示している.更に, 19GHz帯において試作実験を行い, 数値計算による検討の妥当性を確認している.
  • M Yamamoto, K Itoh
    IEE PROCEEDINGS-MICROWAVES ANTENNAS AND PROPAGATION 147 (5) 385 - 389 1350-2417 2000/10 [Refereed][Not invited]
     
    Excitation of the parallel plate mode is a serious concern in a stripline slot-coupled patch antenna, and the paper is a study of its behaviour. Frequency dependence of the parallel plate mode power ratio to the input power of the antenna is discussed by means of an equivalent circuit of the antenna. It is found that the parallel plate mode power ratio is very small when the antenna is operated at the resonant frequency of the patch. A prototype antenna (in which impedance matching is obtained at the resonant frequency of the patch) is designed and fabricated. Measurement of the parallel plate mode power is performed to confirm the validity of the considerations. It is concluded that the antenna should be operated at the resonant frequency of the patch to minimise the unwanted effect concerning the parallel plate mode.
  • YAMAMOTO Manabu, KAMIKAWA Tomohiko, ITOH Kiyohiko
    Proceedings of the Society Conference of IEICE 一般社団法人電子情報通信学会 2000 (1) 64 - 64 2000/09 [Not refereed][Not invited]
  • HATTORI Kazuya, YAMAMOTO Manabu, ITOH Kiyohiko
    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 83 (9) 819 - 825 1345-2827 2000/09 [Refereed][Not invited]
     
    NRDガイドの変形であるイメージNRDガイドはミリ波帯での応用が期待される.イメージNRDガイドを含む回路・アンテナを構成し, その特性評価を行うためには, 他の導波路への変換器が必要となる.本論文では, 方形導波管からイメージNRDガイドへの変換構造を提案し, その動作原理について説明する.また, 実効誘電率(EDC)法に基づく数値計算により, R帯(30GHz帯)での動作を見込んだ変換器の設計を行う.更に, 設計した変換器について試作測定を行い, 提案する変換器の有効性を示す.
  • Manabu Yamamoto, Kousuke Ishizaki, Mitsuru muramoto, Kanemi Sasaki, Kiyohiko Itoh
    Proceedings of the 2000 International Symposium on Antennas and Propagation 1 205 - 208 2000/08 [Refereed][Not invited]
  • Kawamura Teruo, Yamamoto Manabu, Itoh Kiyohiko
    IEICE technical report. Antennas and propagation 一般社団法人電子情報通信学会 100 (217) 61 - 66 0913-5685 2000/07 [Not refereed][Not invited]
     
    In Wireless Local Area Networks, A multi-sector antenna is often used to avoid the degradation of transmission quality due to the multipath propagation. This report presents a planar-type multi-sector antenna made by a printed slot Yagi-Uda array. Characteristics of the proposed antenna are evaluated by using the spectral domain moment method. It is clarified from the numerical results that interaction between the sectors is extremely small in the proposed antenna. Experiment is also performed at 19GHz band to demonstrate the numerical considerations.
  • Oasakabe Taro, Yamamoto Manabu, Itoh Kiyohiko
    IEICE technical report. Antennas and propagation 一般社団法人電子情報通信学会 100 (217) 41 - 46 0913-5685 2000/07 [Not refereed][Not invited]
     
    In General, main beam direction of leaky-wave antennas is not broadside because of the traveling wave type source distribution. An Image NRD guide resonant-type leaky wave antenna, which was previously proposed by the authors, poses a standing wave type source distribution. This feature results in the broadside radiation with low side lobe level and high directivity. In this report, we propose the Image NRD guide resonant-type leaky wave antenna with waveguide feed. Characteristics of the antenna, such as return loss and rediation pattern, are considered through experiments carried at R-band.
  • YAMAMOTO Manabu, ISHIZAKI Kosuke, MURAMOTO Mitsuru, SASAKI Kanemi, 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 83 (6) 836 - 844 1344-4697 2000/06 [Refereed][Not invited]
     
    マイクロストリップ線路で直列給電されたスロットアレーアンテナに着目し, 無線LAN用平面マルチセクタアンテナの構成要素とするための設計法について検討している.スロット間の相互結合を無視した設計法に基づき, エンドファイア方向へのビームチルトを実現するための励振法について考察している.これによりバックワード励振が有効なことを明らかにしている.スペクトル領域モーメント法によるアンテナのモデル化を行い, 相互結合を考慮に入れた設計を行っている.更に, 試作測定を行うことにより, モデル化の妥当性と提案した設計法の有効性を確認している.
  • CHIRWA Lawrence C, MORIMOTO Kenji, SUGAWARA Yasutaka, YAMAMOTO Manabu, 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 83 (6) 872 - 880 1344-4697 2000/06 [Refereed][Not invited]
     
    ミリ波回路としてNRDガイドと同様の低損失性を有するイメージNRDガイドのイメージ面に設置した横スロットのアレーは導波管アレー理論により設計できる.本論文では, 設計に必要な横スロットの規格化インピーダンスを定在波測定から求める手法を示す.スロット近傍では, スロットで生じた散乱界により定在波分布が乱されることから, 散乱界の影響を受けないスロットからの最小距離を求める方法を明らかにし, 条件を満足する範囲の定在波分布から規格化インピーダンスの評価を行う.更に, 評価法の妥当性及び有効性を明らかにするため, 時間領域差分(FDTD)法を用いた解析を行い, 実験結果と比較検討する.最後に, アレーアンテナの設計例を示し, 提案した測定法及び導出した規格化インピーダンスのアレーアンテナ設計への適用可能性を確認している.
  • YAMAMOTO 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 83 (4) 510 - 517 1344-4697 2000/04 [Refereed][Not invited]
     
    漏れ波アンテナは進行波の形態で波源配置を行っており, 最大放射方向はブロードサイドとならない.本論文では, 共振型の波源配置によりブロードサイド放射を可能にしたイメージNRDガイド漏れ波アンテナを提案し, その動作原理を明らかにする.プローブ給電並びにスロット結合給電を用いたイメージNRDガイド漏れ波アンテナの試作測定をKu帯で行い, サイドローブレベルが-20dB以下のブロードサイド放射が得られることを確認している.
  • ISHIZAKI Kousuke, YAMAMOTO Manabu, MURAMOTO Mitsuru, SASAKI Kanemi, ITOH Kiyohiko
    Proceedings of the IEICE General Conference 一般社団法人電子情報通信学会 2000 (1) 123 - 123 2000/03 [Not refereed][Not invited]
  • KAWAMURA Teruo, ISHIZAKI Kohsuke, YAMAMOTO Manabu, ITOH Kiyohiko
    Proceedings of the IEICE General Conference 一般社団法人電子情報通信学会 2000 (1) 122 - 122 2000/03 [Not refereed][Not invited]
  • YAMAMOTO Manabu, HATTORI Kazuya, OSAKABE Taro, ITOH Kiyohiko
    Proceedings of the Society Conference of IEICE 一般社団法人電子情報通信学会 1999 (1) 98 - 98 1999/08 [Not refereed][Not invited]
  • Chirwa Lawrence C, Morimoto Kenji, Yamamoto Manabu, OMIYA Manabu, ITOH Kiyohiko
    IEICE technical report. Antennas and propagation 一般社団法人電子情報通信学会 99 (210) 7 - 13 0913-5685 1999/07 [Not refereed][Not invited]
     
    In order to design an array antenna consisting of transverse slots in the image plane of an image NRD guide using the design method for waveguide slot arrays, the normalized impedance of the transverse slot needs to be known. This paper discusses a method for determining the normalized impedance of a transverse slot in the image plane of the image NRD guide using measurements of standing wave ratio. Moreover, the finite-difference time-domain technique is employed to determine the normalized impedance and good agreement is obtained with measured results.
  • Ishizaki Kosuke, Yamamoto Manabu, Itoh Kiyohiko
    IEICE technical report. Antennas and propagation 一般社団法人電子情報通信学会 99 (210) 1 - 6 0913-5685 1999/07 [Not refereed][Not invited]
     
    A Slot array antenna with backward excitation (BWSA) is useful as a component of a multi-sector antenna for the wireless LANs. A study on undesirable back radiation of the BWSA is performed using the spectral domain moment method. The use of a thin cavity is proposed, and it is shown that the undesirable radiation is effectively suppressed when the cavity width is designed so as to become cutoff at the operation frequency. Experimental results obtained at 19GHz band validate our proposal.
  • KAICHIDA Tsuyoshi, ISHII Nozomu, YAMAMOTO Manabu, NISHIMURA Toshihiko, 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 82 (6) 1177 - 1184 1344-4697 1999/06 [Refereed][Not invited]
     
    ミリ波帯においては, 伝送線路による損失が大きいという問題が生じる. そこで, アンテナとミキサを一体化し, 伝送損失を軽減することのできる準光学アンテナミキサがある. これは, 高周波と局部発信周波の異なる二つの周波数を空間的に受信し, 直後に中間周波数に変換するものである. これを実現することのできるアンテナとして, コプレーナ導波路給電による2周波動作可能なマイクロストリップアンテナがある. 本論文においては, スペクトル領域モーメント法を用い, このアンテナの周波数1/20スケールモデルの入力特性をマイクロ波帝で解析し, 異なる二つの周波数で独立に動作可能であることを示す. 更に, 本アンテナの放射指向性を絶対利得により評価する.
  • M. Yamamoto, K. Itoh
    Electronics Letters 35 (11) 857 - 858 0013-5194 1999/05/27 [Refereed][Not invited]
     
    A novel leaky-wave antenna constructed from an image non-radiating dielectric waveguide (INRDG) is presented. Unlike conventional leaky-wave antennas, the broadside radiation is realized by utilizing the resonant characteristic of the leaky INRDG waveguide mode. Experimental results measured at Ku band confirm the effective performance of the antenna.
  • YAMAMOTO Manabu, ITOH Kiyohiko
    Proceedings of the IEICE General Conference 一般社団法人電子情報通信学会 1999 (1) 93 - 93 1999/03 [Not refereed][Not invited]
  • ISHIZAKI Kousuke, YAMAMOTO Manabu, MURAMOTO Mitsuru, SASAKI Kanemi, ITOH Kiyohiko
    Proceedings of the IEICE General Conference 一般社団法人電子情報通信学会 1999 (1) 91 - 91 1999/03 [Not refereed][Not invited]
  • Manabu Yamamoto, Kiyohiko Itoh
    IEEE Antennas and Propagation Society International Symposium: Wireless Technologies and Information Networks, APS 1999 - Held in conjunction with USNC/URSI National Radio Science Meeting 2 800 - 803 1999 [Refereed][Not invited]
     
    The purpose of this paper is to propose a new leaky-wave antenna constructed from an image non-radiating dielectric (NRD) waveguide. A half sinusoidal source distribution, which is very long in comparison with the free-space wavelength, is realized by using a resonant phenomenon of a leaky mode near its cutoff frequency. Thus the broadside radiation with low side lobe level and high directivity can be obtained. Experimental results measured at Ku band are presented to demonstrate the effective performance of the proposed antenna.
  • YAMAMOTO Manabu, OZAKI Kohichi, 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 81 (10) 949 - 956 0915-1885 1998/10 [Refereed][Not invited]
     
    トリプレート型スロット結合パッチアンテナ(TSCPA:Triplate line fed Slot Coupled Patch Antenna)では, 放射パッチの共振周波数でパラレルプレートモードの発生量が最小になる.しかし, この周波数での入力インピーダンスの抵抗分(入力抵抗)は極めて低い.そこで, 本論文では, パッチの共振周波数における入力抵抗の上昇法を提案する.TSCPAの等価回路を用いて, パッチの共振周波数での入力抵抗は, スロットの誘導的な効果により低下していることを明らかにする.また, 誘導的効果による入力抵抗の低下を緩和するための, スロットの設計指針について検討する.更に, 共振長よりも短いストリップをパッチとスロットの間に配置し, 誘導的効果を相殺すれば, 入力抵抗が上昇することを示す.
  • YAMAMOTO Manabu, ITOH Kiyohiko
    Proceedings of the Society Conference of IEICE 一般社団法人電子情報通信学会 1998 (1) 49 - 49 1998/09 [Not refereed][Not invited]
  • YAMAMOTO Manabu, ITOH Kiyohiko
    Proceedings of the IEICE General Conference 一般社団法人電子情報通信学会 1998 (1) 136 - 136 1998/03 [Not refereed][Not invited]
  • M Yamamoto, K Itoh
    IEEE ANTENNAS AND PROPAGATION SOCIETY INTERNATIONAL SYMPOSIUM - ANTENNAS: GATEWAYS TO THE GLOBAL NETWORK, VOLS 1-4 2 (34.10) 932 - 934 1998 [Refereed][Not invited]
  • M Yamamoto, K Itoh
    ELECTRONICS AND COMMUNICATIONS IN JAPAN PART I-COMMUNICATIONS 81 (1) 31 - 40 8756-6621 1998/01 [Refereed][Not invited]
     
    A triplate type slot coupled microstrip antenna provides an antenna for which the feed circuit can be multilayered. In this paper, we present an analytical discussion concerning suppression of leakage power in the parallel plate mode. The method of analysis used is the spectral domain moment method, for which a full-wave analysis is possible. It is shown that the rate of the parallel plate mode versus the input power takes a minimum at the resonant frequency of the patch itself due to the series resonance of the patch. This phenomenon is discussed by means of an equivalent circuit. The input impedance at this resonant frequency is low, so that matching cannot be obtained by the adjustment of the element alone. In order to use the above phenomenon as a suppression method for the parallel plate mode, a structure with a parallel stub is proposed. It is experimentally demonstrated that this structure is effective for suppression of the parallel plate mode. (C) 1998 Scripta Technica.
  • YAMAMOTO Manabu, ITOH Kiyohiko
    IEICE technical report. Antennas and propagation 一般社団法人電子情報通信学会 97 (453) 67 - 74 1997/12 [Not refereed][Not invited]
     
    The use of a triplate line in a slot-coupled patch antenna (SCPA) causes the excitation of the parallel plate mode. The power leakage to the parallel plate mode leads to the decrease of the radiation efficiency of the antenna. It has been found that the power leakage to the mode can be suppressed at the resonant frequency of the patch, and that frequency dependent characteristic of the leakage power ratio is insensitive to the slot length. In this report, first, a lumped element circuit representation of SCPA is derived using the moment method in the spectral domain. Physical backgrounds of...
  • OZAKI Kohichi, YAMAMOTO Manabu, ITOH Kiyohiko
    IEICE technical report. Electromagnetic compatibility 一般社団法人電子情報通信学会 97 (286) 1 - 6 1342-6893 1997/09 [Not refereed][Not invited]
     
    In a slot coupled microstrip antenna with a triplate line feed, the parallel plate mode can be successfully suppressed when the antenna is operated at the series resonant frequency of the radiating patch. However the antenna has low input resistance in this case. In this report, we perform analytical considerations on the input properties of the antenna to achieve high input resistance at the series resonant frequency. Numerical results indicate that input resistance is decreabed because of the inductive effect due to the slot. Then we propose the use of a parasitic strip to cancel the indu...
  • YAMAMOTO Manabu, ITOH Kiyohiko
    Proceedings of the Society Conference of IEICE 一般社団法人電子情報通信学会 1997 (1) 112 - 112 1997/08 [Not refereed][Not invited]
     
    トリプレート型スロット結合マイクロストリップアンテナにおいては, パラレルプレートモードによる放射効率の低下などが問題となる. このモードの抑制法として, パッチの直列共振周波数においてアンテナを動作させる手法が提案されている. この場合, 並列スタブなどの整合回路を用いる必要がある. しかしながら, 上記周波数における入力インピーダンスの抵抗分は, パッチの直列共振のために非常に小さく, 整合回路の設計・製作が難しくなるという問題がある. 本稿では, 抵抗分を大きくするために, 寄生素子を装荷した構造について検討したので報告する.
  • Parallel-Plate Mode Suppression in a Slot-Coupled Microstrip Antenna with a Triplate Line Feed
    Manabu Yamamoto, Kiyohiko Itoh
    Conference Publication No 436 Tenth International Conference on Antennas and Propagation 1 119 - 122 1997/04 [Refereed][Not invited]
  • YAMAMOTO 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 80 (4) 333 - 341 0915-1885 1997/04 [Refereed][Not invited]
     
    給電回路の多層化が容易なアンテナとしてトリプレート型スロット結合マイクロストリップアンテナがある. 本論文では, このアンテナにおいて問題となる, パラレルプレートモードへの漏えい電力の抑制に関して解析的な検討を行っている. 解析手法としてはfull-wave解析が可能なスペクトル領域モーメント法を用いている. 入力電力に対するパラレルプレートモード電力の割合は, パッチの直列共振により, パッチ自体の共振周波数において最小となることを示し, この現象について等価回路を用いた検討を行っている. この共振周波数における入力インピーダンスは低く, 素子の調整のみでは整合を得ることはできない. そこで, 上記現象をパラレルプレートモードの抑制法として用いるために, 並列スタブを設けた構造を提案している. 更に, この構造がパラレルプレートモードの抑制に有効であることを実験的に示している.
  • YAMAMOTO Manabu, ITOH Kiyohiko
    Proceedings of the IEICE General Conference 一般社団法人電子情報通信学会 1997 (1) 111 - 111 1997/03 [Not refereed][Not invited]
     
    トリプレート型スロット結合マイクロストリップアンテナにおいては, 線路の接地板間を伝搬するパラレルプレートモードが発生し, 放射効率の低下, 素子間の結合が生じる. このモードの抑制法として, 我々は先にパッチの直列共振を用いた手法を提案し, 単一素子の場合について検討を行い, 放射効率が改善されることを示した. 本稿では, 2素子アレーとした構造に対して上記抑制法を適用し, 放射特性について解析的に検討を行ったので報告する.
  • M Yamamoto, K Itoh
    ELECTRONICS LETTERS 33 (6) 441 - 443 0013-5194 1997/03 [Refereed][Not invited]
     
    In a slot-coupled microstrip antenna with a triplate line feed, the parallel-plate mode is excited by the slot, resulting in a decrease of radiation efficiency. The authors present a technique for suppressing the parallel-plate mode in this type of the antenna. Measured results confirm the effective performance of the proposed method.
  • K Itoh, M Yamamoto
    IEEE ANTENNAS AND PROPAGATION SOCIETY INTERNATIONAL SYMPOSIUM 1997, VOLS 1-4 4 2135 - 2136 1997 [Refereed][Not invited]
  • Theoretical Considerations on Parallel-Plate Mode Suppression in a Slot-Coupled Microstrip Antenna with a Stripline Feed
    Manabu Yamamoto, Toshiyuki Miyazaki, Kiyohiko Itoh
    Proceedings of the 1996 International Symposium on Antennas and Propagation 3 841 - 844 1996/09 [Refereed][Not invited]
  • YAMAMOTO 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 79 (9) 631 - 634 0915-1885 1996/09 [Refereed][Not invited]
     
    本論文では,パラレルプレートモードおよび表面波モードがトリプレート型スロット結合マイクロストリップアンテナの電力特性に与える影響を解析的に検討している.また,放射素子の動作と本アンテナの電力特性との関係についても言及している.
  • YAMAMOTO Manabu, ITOH Kiyohiko
    IEICE technical report. Antennas and propagation 一般社団法人電子情報通信学会 96 (91) 7 - 14 1996/06 [Not refereed][Not invited]
     
    The design of multilayer feeding network can be easily achieved in a slot coupled microstrip antenna with a triplate line feed. In this report, we perform theoretical considerations on parallel-plate mode suppression in this antenna. For the analysis, we use the moment method in the spectral domain. The proportion of the parallel-plate mode power to the input power has the minimum value at the resonant frequency of the patch itself due to the series resonance of the patch. We clarify this mechanism using the equivalent circuit of the antenna. Then we proposed a new geometry which has a shun...
  • YAMAMOTO Manabu, ITO Kiyohiko
    Proceedings of the IEICE General Conference 一般社団法人電子情報通信学会 1996 (1) 61 - 61 1996/03 [Not refereed][Not invited]
     
    スロット結合マイクロストリップアンテナにおいてトリプレート線路を用いることにより,スロットおよび給電線により生じるアンテナ後方への不要放射を抑圧することができる.しかしながらこの場合,トリプレート線路を構成する接地板間を伝搬するパラレルプレートモードが発生し,放射効率を低下させる原因となる.この不要モードを抑圧する手法として接地板間をスルーホールで短絡する手法が提案されているが,製作行程が複雑になる.本稿では,パッチの共振を用いた抑圧法について解析的な検討を行う.
  • YAMAMOTO Manabu, ITOH Kiyohiko
    Proceedings of the Society Conference of IEICE 一般社団法人電子情報通信学会 1995 (1) 53 - 53 1995/09 [Not refereed][Not invited]
     
    アクティブ素子との集積化が容易なアンテナとしてスロット結合マイクロストリップアンテナがある.本アンテナにおいて特に問題となるアンテナ背面への不要放射および給電側における各種導波モードへの電力漏洩による損失に関する検討はいくつかの報告がなされているが,放射素子の振る舞いとこれらの特性の関係に着目した検討はなされていない.本稿では,放射素子(パッチ)の共振現象と給電側における各種電力との関係について検討を行う.

MISC

Books etc

  • アンテナ・無線ハンドブック
    山本学 (Contributor)
    オーム社 2007/10

Association Memberships

  • IEEE   THE INSTITUTE OF ELECTRONICS, INFORMATION AND COMMUNICATION ENGINEERS.   

Research Projects

  • Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research
    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.
  • Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research
    Date (from‐to) : 2016/10 -2019/03 
    Author : Yamamoto Manabu
     
    With the spread of ultra-high-speed wireless systems, tightness of frequency resources is becoming a serious problem. It is effective to introduce high-speed wireless transmission methods such as Multiple-Input-Multiple-Output (MIMO) technology in unused frequency bands as a measure against the tightness of frequency resources. In this research subject, high-performance antenna technologies applicable to high-speed wireless transmission system in unused frequency band have been developed. Antenna technologies for constructing MIMO antenna systems in unused frequency bands have been developed. Based on these technologies, multiport MIMO antennas have been developed.
  • Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research
    Date (from‐to) : 2011 -2013 
    Author : YAMAMOTO Manabu
     
    Next-generation wireless communication systems for the purpose of achieving ultra high-speed data transmission in mobile communication environments have attracted considerable attention in recent years. MIMO and UWB play important roles as key technologies in realizing the next-generation wireless communication systems. The achievements obtained in this study are the developments of effective way for constructing miniaturized antennas that may be useful for high-speed wireless communication systems based on MIMO and UWB technologies. Techniques for realizing small and high-performance MIMO antennas that can be used in various kinds of miniaturized mobile terminals have been developed in this study. In addition to these achievements, design techniques of miniaturized antennas having ultra-wideband characteristics have been developed for the case where the both of MIMO and UWB techniques are used in the same time in high-speed wireless communication systems.
  • 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, 野島 俊雄, 日景 隆
     
    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...
  • 次世代近距離無線通信技術の施設内センサネットワークへの応用に関する研究
    特別教育研究経費連携融合事業 「協働型開発事業－地域ＣＯＥの形成－」
    Date (from‐to) : 2007 -2007 
    Author : 山本学
  • 施設内センサネットワークへのUWB無線の応用に関する研究
    特別教育研究経費連携融合事業 「協働型開発事業－地域ＣＯＥの形成－」
    Date (from‐to) : 2006 -2006 
    Author : 山本学
  • 文部科学省：科学研究費補助金(若手研究(B))
    Date (from‐to) : 2004 -2006 
    Author : 山本 学
     
    高速データ伝送を無線で行うための手段として,UWB無線システムが注目を集めている.本研究の目的は,インパルス信号の送受信に適した,UWB無線システム用の超広帯域アンテナを平面構造で実現するための基礎技術を確立し,同システムの実用化および小型化に資するところにある.本年度は,準ミリ波UWBレーダー等に応用可能な超広帯域平面型アレーアンテナを実現するための基礎検討を行い,以下の成果を得た.(a)ファンビームを有する超広帯域リニアアレーアンテナを設計した.アレーアンテナの 基本素子として自己補対アンテナの一形式である葉形プリントダイポールアンテナを提案し,その設計指針を明らかにするとともに,UWB用として利用が想定されている周波数帯域にわたる整合の実現と放射特性の安定化を図るためのアレー構成法を開発した.(b)上記(a)において開発したリニアアレーを複数個,2次元配列することにより,ペンシルビームを有する超広帯域平面型アレーアンテナを実現した.各リニアアレーへの給電回路の構成を工夫し,UWB用として利用が想定されている周波数帯域にわたる整合状態と放射特性の安定性を図った.(c)上記のファンビームアレーアンテナおよびペンシルビームアレーアンテナの実験的評価を行い,その結果を適宜フィードバックすることにより,超広帯域平面アレーアンテナの一構成法を確立した。以上,本年度において予定してい...
  • RFID用アンテナ
    三菱電機株式会社：
    Date (from‐to) : 2005 -2005 
    Author : 山本学
  • UWB無線システム用平面形アンテナ基本技術の開発
    特別教育研究経費連携融合事業 「協働型開発事業－地域ＣＯＥの形成－」
    Date (from‐to) : 2005 -2005 
    Author : 山本学
  • Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research
    Date (from‐to) : 2001 -2003 
    Author : OHGANE Takeo, YAMAMOTO Manabu, NISHIMURA Toshihiko, OGAWA Yasutaka
     
    In multiple-input multiple-output systems, most common application is space division multiplexing (SDM) where individual data substreams are transmitted from multiple antennas with the same power and the same rate. SDM applications assume that MIMO channel information in not available at the transmitter. If we know all of MIMO channel information, it is possible to assign matched beam to each substream where the optimum weight for beamforming is obtained by singular value decomposition of MIMO channel matrix. We call SDM with eigenbeam-forming as E-SDM, hereafter. In E-SDM, we have to consider resource (transmit power and data rate) adaptation. In this research, we employed minimum brt error rate (BER) criterion as expansion of transmit power control per sucarrier previously used in OFDM systems. As a result, E-SDM with the resource adaptation obtained higher BER performance in comparison to conventional SDM. However, the MIMO channel information required at the transmitter includes estimation and tracking errors. Under such errors, we also evaluated the E-SDM performance. The results show that degradation due to the channel estimation error is almost the same to E-SDM and SDM applications. Although the channel tracking error caused by a time lag until transmission degrades E-SDM performace severely when the maximum Doppler frequency is very high, we have shown that it can be compensated by employing the first-order extrapolation of estimated channel.
  • Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research
    Date (from‐to) : 2000 -2002 
    Author : OMIYA Manabu, HIKAGE Takasi, YAMAMOTO Manabu
     
    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 plates, respectively. Both realize a good impedance matching at the frequency of 2.45 GHz. It is clarified from calculations that the antenna parameters are effective for the array antenna design and that the mutual coupling between the excited element and its adjacent ones in the direction of H-plane is considerably large. Additional calculations for the nine-element and the twenty-five-element array antennas show that quantities of return loss and mutual couplings are almost the same for both array geometries. So the evaluation of mutual coupling for the nine-element array antenna gives us good perspectives of that in the large-scale array antenna. Second, we discussed another type of antenna element excited by an inverted-F element. The elements are composed of the two conductive plates separated by the eight square pillars of 12 mm high. If we use metal pipes as the pillars, we can realize an easy method to configure the element as the two conductive plates are fixed with screws. Furthermore, the antenna configuration has advantages such that the feeder is set on the bottom conductive plate and is not connected with the upper plate. This type of element is configured with fewer posts than the previous one.
  • 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) : 1999 -2000 
    Author : 山本 学
     
    本研究の目的は,電磁結合パッチアンテナを用いたマイクロ波帯およびミリ波無線LANシステム用平面アンテナを実現するための基礎技術を開発することにある.本年度は,以下に示す知見と成果を得た.(1)平成11年度において開発したプリントスロットアレーに,パッチ素子を組み合わせ,電磁結合パッチアレーを構成した.このアレーについて,スペクトル領域モーメント法を用いた数値シミュレーションを行い,無線LANシステムに適合する放射指向性を得るための設計指針を確立した.(2)平成11年度において開発したプリントスロットアレーで構成したマルチセクタアンテナについて,スペクトル領域モーメント法を用いて,セクタ間干渉,放射指向性などの特性評価を行った.この結果より,従来のマルチセクタアンテナのように,金属フィンなどの突起物を配置しなくとも,セクタ間の相互干渉が極めて小さな平面マルチセクタアンテナが実現可能であることを明らかにした.(3)電磁結合パッチアレーにおいて特性劣化の原因となる平行平板モードについて,スペクトル領域モーメント法から導いた等価回路を用いることにより,発生機構を明らかにした.また,平行平板モードを抑制するための指針を明らかにした.(4)(2)に示した平面マルチセクタアンテナの試作測定を19GHz帯において行い,数値シミュレーションによる検討の妥当性を明らかにした.以上,本年度予定して...
  • Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research
    Date (from‐to) : 1995 -1998 
    Author : ITOH Kiyohiko, ISHII Nozomu, YAMAMOTO Manabu, OGANE Takeo, OMIYA Manabu, OGAWA Yasutaka
     
    (1) A novel quasi-optical antenna mixer has been developed. The antenna mixer consists of a coplanar waveguide fed dual-frequency microstrip antenna and Schottky-barrier diode connected to the end of the guide. A novel beam scanning system in which the phase shifter is not used has been realized using the antenna mixer. (2) An image NRD guide (iNRDG) has been proposed as a low-loss guide in the millimeter-wave band. A transverse slot cut on the image plate of the iNRDG has been developed as a novel millimeter-wave antenna. To design the array of the transverse slot, an analysis and a measurement method of the normalized impedance has been developed. (3) A novel coaxial feed technique of the image dielectric waveguide (DIL) has been proposed. In addition, a transition between DIL and iNRDG has been investigated. The validity of the proposals has been confirmed using experimental results and FDTD analysis. (4) Behavior of parallel plate mode in a triplate-type slot-coupled microstrip antenna has been clarified through the use of the spectral domain moment method. A novel suppression technique of the parallel plate mode has been also investigated. (5) A novel printed slot array antenna, in which a backward excitation is employed, has been developed as an element of sector antenna for millimeter-wave wireless LAN systems. A rigorous design technique of the array antenna has been investigated. In the technique, the spectral domain moment method is used.

Industrial Property Rights

  • 特許第3754280号:セクタアンテナ  
    株式会社日立国際電気, 伊藤 精彦, 村本充, 佐々木金見, 山本学
  • 特許第3725766号:キャビティ付きスロットアレーアンテナ  
    村本充, 佐々木金見, 伊藤 精彦, 山本 学
  • 特許第3062602号:共振型漏洩波空中線  
    伊藤 精彦, 山本 学

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