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  2. 高橋 応明

高橋 応明

タカハシ マサハル  (Masaharu Takahashi)

基本情報

所属
千葉大学 フロンティア医工学センター 准教授
学位
博士(工学)(東京工業大学)
Ph.D.(東京工業大学)
J-GLOBAL ID
200901040108092262
researchmap会員ID
1000169309
外部リンク

研究キーワード

 3

研究分野

 1

受賞

 21
もっとみる

論文

 179
  • Daiki NOMURA, Ryota AKINO, Matthew CORKILL, Keizo HIRANO, Akihide KASAI, Seiji KATAKURA, Yusuke KAWAGUCHI, Tatsuya KAWAKAMI, Riri KIMURA, Delphine LANNUZEL, Ryosuke MAKABE, Mirai MATSUURA, Kohei MATSUNO, Klaus MEINERS, Keizo NAGASAKI, Yuichi NOSAKA, Nana SAMORI, Shinnosuke SAKAYA, Eun Yae SON, Ryotaro SUGA, Yumi SUNAKAWA, Keigo D. TAKAHASHI, Masaharu TAKAHASHI, Yuka TAKEDA, Takenobu TOYOTA, Manami TOZAWA, Pat WONGPAN, Hiroshi YOSHIDA, Kazuhiro YOSHIDA, Masaki YOSHIMURA
    Bulletin of Glaciological Research 42 19-37 2024年6月  査読有り
  • Shinnosuke Sakaya, Masaharu Takahashi
    IEICE Communications Express 13(6) 168-171 2024年6月  査読有り最終著者責任著者
  • Ngu War Hlaing, Kamilia Kamardin, Yoshihide Yamada, Takuji Arima, Masaharu Takahashi, Naobumi Michishita
    IEEE Open Journal of Antennas and Propagation 5(2) 340-535 2024年4月  査読有り
    Meander Line Antenna (MLA) is widely employed in compact electronic devices, such as cellular phones and WLAN terminals, owing to its electrically small size. To facilitate practical antenna design, essential equations encompassing self-resonant structure, input resistance, antenna efficiency, and Q factor have been systematically developed. However, the prior self-resonant equations included only inductive reactance (XC), neglecting the capacitive reactance (XD) equation. This manuscript addresses this gap by introducing new design equations, presenting a newly derived XD equation and an improved Q factor expression. The inadequacies of the existing Q factor equation, reliant on the radius of a sphere encompassing the antenna, are addressed by proposing a more fitting expression that incorporates antenna structural parameters using the ratio of reactance to resistance. The overview of existing design equations sets the stage for the introduction of these newly developed equations. To assess the accuracy of electromagnetic (EM) simulation results, a comparative analysis is conducted between simulated and theoretically calculated input resistance values. The derivation of new reactance equations involves the development of XC equations based on electromagnetic theory. The XD equation is established by deriving the stored charge equation from electrical near-field distributions obtained through EM simulations. By applying the relationship between charge and capacitance, a new XD equation is obtained. Subsequently, a new self-resonant equation is derived, and the validity of the newly derived equations is confirmed through EM simulation results, ensuring their accuracy. Two MLA prototypes, with lengths of 0.05 and 0.1 wavelengths at 405 MHz, are fabricated and experimentally validated. Smith chart measurements confirm the self-resonant condition and input resistance. By correlating with the VSWR characteristics, the obtained Q factor of approximately 100 aligns successfully with the results from the reactance equation. The antenna gain is verified at -7.7 dBi and -3.5 dBi for antennas with lengths of 0.05 and 0.1 wavelengths, respectively. These findings establish the practical applicability of the proposed equations for antenna design and elucidate the performance of practical antennas.
  • e28061-e28061 2024年3月  査読有り最終著者
  • Tomoki CHIBA, Yusuke ASANO, Masaharu TAKAHASHI
    IEICE Transactions on Communications E107-B(1) 206-213 2024年1月1日  査読有り最終著者責任著者
もっとみる

MISC

 623
  • 秋元 晋平, 齊藤 ー幸, 高橋 応明, 伊藤 公一
    電子情報通信学会ソサイエティ大会講演論文集 2010(1) 127-127 2010年8月31日  
  • 平岡 拓海, 齊藤 一幸, 高橋 応明, 伊藤 公一, 天野 良晃, 中野 雅之, 石川 博康
    電子情報通信学会ソサイエティ大会講演論文集 2010(1) 168-168 2010年8月31日  
  • 渡辺 亮平, 齊藤 一幸, 渡辺 聡一, 高橋 応明, 伊藤 公一
    電子情報通信学会ソサイエティ大会講演論文集 2010(1) 313-313 2010年8月31日  
  • 熊谷 俊宏, 齊藤 一幸, 高橋 応明, 伊藤 公一
    電子情報通信学会ソサイエティ大会講演論文集 2010(1) "S-2" 2010年8月31日  
  • 高橋 応明, 齊藤 一幸, 伊藤 公一
    電子情報通信学会ソサイエティ大会講演論文集 2010(1) "S-5"-"S-6" 2010年8月31日  
  • 天野 良晃, 中野 雅之, 石川 博康, 小野田 倫之, 高橋 応明, 伊藤 公一
    電子情報通信学会技術研究報告. A・P, アンテナ・伝播 110(135) 19-24 2010年7月14日  
    近年,移動通信環境における高速かつ大容量データ通信を実現するために, MIMO(Multiple-Input Multiple-Output)技術を用いた次世代通信システムの研究が活発に行われている.これまでに,携帯電話を想定した小型基板に実装したMIMOアンテナについて,人体影響を含めた実利用環境でのアンテナ特性や電波伝搬路特性も考慮したMIMOチャネル伝送容量を,計算機シミュレーションや屋外実験を通して評価した結果が報告されている.しかし,これらの条件下で,屋外実験を通じて基地局送信に空間及び直交偏波MIMOを用いた場合の特性評価は十分に行われていない.本稿では,小型基板に実装したMIMOアンテナの2×2MIMO伝送時のMIMOチャネル容量について人体影響の有無,及び基地局送信の空間・直交偏波MIMOについて特性評価を行ったため報告する.
  • 宇野 由美子, 齋藤 一幸, 高橋 応明, 伊藤 公一
    電子情報通信学会技術研究報告. A・P, アンテナ・伝播 110(23) 7-10 2010年5月6日  
    人体近傍で用いられる無線通信機器のアンテナの設計では,人体との相互作用を考慮することが重要である.一般に,その作用を評価するためには,人体の組織構造を簡易的に模擬した均質ファントムを用いる.しかしながら,均質なモデルを用いたアンテナ特性評価の妥当性の検討例は少ない.本稿では,人体の組織構造がアンテナ特性に与える影響の基礎的な検討として,ループアンテナを均質媒質モデルと層構造モデルの近傍に配置し,それらの構造の差異がアンテナの入力特性に与える影響を測定し,計算結果と比較した.その結果,実験結果,計算結果ともに,アンテナとファントムが近接時に,その組織構造がアンテナ特性に与える影響が大きいことを確認した.
  • 上村 貴良, 齊藤 一幸, 高橋 応明, 伊藤 公一
    電気学会研究会資料. EDD, 電子デバイス研究会 2010(46) 71-76 2010年3月4日  
  • 中田 智史, 齊藤 一幸, 高橋 応明, 伊藤 公一
    電気学会研究会資料. EDD, 電子デバイス研究会 2010(46) 77-82 2010年3月4日  
  • 中島 崇志, 齊藤 一幸, 高橋 応明, 伊藤 公一
    電子情報通信学会総合大会講演論文集 2010(1) 87-87 2010年3月2日  
  • 齊藤 一幸, 河村 隆宏, 高橋 応明, 伊藤 公一
    電子情報通信学会総合大会講演論文集 2010(1) 185-185 2010年3月2日  
  • 宇野 由美子, 齊藤 一幸, 高橋 応明, 伊藤 公一
    電子情報通信学会総合大会講演論文集 2010(1) 189-189 2010年3月2日  
  • 櫻岡 萌, 齊藤 一幸, 高橋 応明, 伊藤 公一, 石川 典男
    電子情報通信学会総合大会講演論文集 2010(1) 190-190 2010年3月2日  
  • 佐藤 雄大, 笹森 崇行, 戸花 照雄, 礒田 陽次, 高橋 応明, 宇野 亨
    電子情報通信学会総合大会講演論文集 2010(1) 193-193 2010年3月2日  
  • 菊池 悟, 齊藤 一幸, 高橋 応明, 伊藤 公一
    電子情報通信学会総合大会講演論文集 2010(1) 392-392 2010年3月2日  
  • 秋元 晋平, 長岡 智明, 菊池 悟, 齊藤 一幸, 渡辺 聡一, 高橋 応明, 伊藤 公一
    電子情報通信学会総合大会講演論文集 2010(1) 393-393 2010年3月2日  
  • 渡辺 亮平, 齊藤 一幸, 渡辺 聡一, 高橋 応明, 伊藤 公一
    電子情報通信学会総合大会講演論文集 2010(1) 400-400 2010年3月2日  
  • 上村 貴良, 齊藤 一幸, 高橋 応明, 伊藤 公一
    電子情報通信学会技術研究報告. MW, マイクロ波 109(431) 71-76 2010年2月25日  
    電磁波を用いたがん治療の一つにハイパサーミアがある.これはがん細胞と正常細胞との温熱感受性の違いを利用して,がん細胞のみを選択的に殺傷する治療法である.本治療法では使用するアプリケータによりその加温方法や領域が大きく変化するため,アプリケータ特性は奏効率を左右する重要な要因である.筆者らは,特に腔内加温用のアプリケータについて検討しており,伸縮性を持つ円筒構造MSA型アプリケータを新たに提案した.ここでは,消化管内に本アプリケータを挿入することを想定したモデルを作成し,FDTD法を用いた数値計算により加温特性の異なる二種類のアプリケータを開発するに至った.そこで,人体の電気的特性を模擬した生体等価ファントムを用いた加温実験を行い,その有効性を確認した.
  • 中田 智史, 齊藤 一幸, 高橋 応明, 伊藤 公一
    電子情報通信学会技術研究報告. MW, マイクロ波 109(431) 77-82 2010年2月25日  
    心臓ペースメーカが動作プログラムの更新を行う際に,従来用いられてきた電磁結合方式に替わる通信方法として,体内植込み型アンテナを用いて外部機器との間で通信を行うシステムが提案されている.そこで筆者らは,体内植込み型医療用データ伝送システム(Medical Implant Communications Services : MICS)に割り振られている402〜405MHz帯を利用した,心臓ペースメーカ装荷型アンテナを設計した.本報告では,多数の組織から構成される人体の構造を考慮に入れ,設計したアンテナの有効性を評価するため,高精細数値人体モデルを用いて数値解析を行った.その結果,本アンテナは心臓ペースメーカ装荷型アンテナとして十分有効であることを確認した.
  • 平岡 拓海, 齊藤 一幸, 高橋 応明, 伊藤 公一
    電子情報通信学会技術研究報告. A・P, アンテナ・伝播 109(417) 13-16 2010年2月11日  
    近年,携帯端末の小型化に伴い,携帯端末用アンテナは薄型化され,アンテナの内蔵化が進んでいる.一般に,携帯端末のアンテナ特性は,実使用状況において使用者の手や胴体の影響を受けることが知られている.そこで,携帯端末用アンテナを設計する際には,人体手部がアンテナ特性に与える影響を考慮する必要がある.これまでに,人体手部と同等の電気的特性,形状の手ファントムを用いて,人体手部がアンテナ特性に与える影響を調査した研究報告はいくつかある.しかしながら,携帯端末の使用時を考慮すると,人体手部の位置・形状が一定であるとは考えられない.そこで本研究では,任意に形状を変化させることができる手ファントムを作製した.さらに,作製した手ファントムの有用性を示すために,手ファントムにアンテナを握らせた際のアンテナの人力特性を測定した.この測定結果を,人作手部にアンテナを握らせた際のアンテナの人力特性の測定結果と比較した.
  • 河村 隆宏, 齋藤 一幸, 高橋 応明, 伊藤 公一
    電子情報通信学会技術研究報告. A・P, アンテナ・伝播 109(372) 115-118 2010年1月14日  
    現在,わが国においては,静磁場強度が3TまでのMRI(Magnetic Resonance Imaging)システムが臨床で使用されている.そして更なる画像の高画質化や撮像時間の短縮を実現するために,3T以上の高磁場によるMR撮像技術が研究されている.しかしながら,高磁場化が進むことによるパルス状電磁波の高周波化や,パルスそのものの高出力化により,NMR(Nuclear Magnetic Resonance)信号を送受信するRF(Radio Frequency)コイルに装荷されているコンデンサ容量のばらつきや,その耐圧に問題が生じることが考えられる.そこで,本研究では,集中定数素子であるコンデンサを使用しなくても従来のRFコイルと同等の磁界強度が得られるバードケージコイルを検討した.その結果,提案したコイルが3T MRI用コイルとして使用可能であることが示唆された.
  • Basari, K. Saito, M. Takahashi, K. Ito
    2010 7th International Symposium on Communication Systems, Networks and Digital Signal Processing, CSNDSP 2010 81-85 2010年  
    This paper provided a measurement campaign of simple antenna system mounted on a vehicle by utilising a Japanese geostationary test satellite called Engineering Test Satellite VIII (ETS-VIII). We developed an antenna system that was compact, light weight, and promising in low cost production. The antenna system was built by a 16-cm patch array antenna, which had simple satellite-tracking method that controlled by a control unit as the vehicle's bearing was updated from a navigation system in real time. A Global Positioning System (GPS) module was utilised for navigation system to provide accurate information of the vehicle's position and bearing during travelling. The control unit was used as the antenna-beam control and measured-data acquisition. The antenna system was thoroughly examined in the measurement under the line of sight (LOS) areas as well as the blockage areas in order to evaluate the propagation characteristics caused by utility poles, pedestrian overpasses and vegetation-covered road. In this measurement, received signal power and average bit error rate (BER) were simultaneously retrieved. Steadily received levels and BER were satisfactorily attained during satellite-tracking in LOS area. Moreover, the fade characteristics and BER performance were investigated while signal blockage happened. The measurement results were presented here to grasp their attenuations and effects on the bit error rate in terms of fade depth. With these results, we can consider to design a cost-effective mobile satellite application for future technology. © 2010 IEEE.
  • Koichi Ito, Ryotaro Suga, Nozomi Haga, Masaharu Takahashi, Kazuyuki Saito
    EuCAP 2010 - The 4th European Conference on Antennas and Propagation 2010年  
    In recent years, studies on body-centric or human-body communications have become an important and active area of research owing to their various applications such as e-healthcare, indoor security systems and personal communications. So far, a system that recognizes and authorizes users when the users touch the receiver equipped on a wall has been proposed. However, most of recent investigations based on numerical simulations were conducted with models that include only human body and wearable devices. In fact, there have been few reports about communication link characteristics between wearable devices and external devices equipped on surrounding objects. In this paper, a model that includes a receiver on a wall was developed, and fundamental characteristics were numerically analyzed by using the finite-difference time-domain (FDTD) method.
  • Takayuki Sasamori, Yudai Satoh, Teruo Tobana, Yoji Isota, Masaharu Takahashi, Toru Uno
    2010 IEEE International Symposium on Antennas and Propagation and CNC-USNC/URSI Radio Science Meeting - Leading the Wave, AP-S/URSI 2010 2010年  
    Recently, body-centric wireless communication using a device including a radio terminal placed in/on body has received a lot of attention [1]. In order to investigate the transmission mechanism of the wearable device for on-body wireless communications analytically, we derive the exact solution represented by the eigenfunction solution for the scattered electric field and discuss them. We then consider the propagation characteristic by the wearable device attached to a human arm by approximating the arm as a dielectric circular cylinder. First, the frequency-domain integral representations of the eigenfunction solutions for the scattered electric fields are derived. From this, the transmission coefficient between the transmitting and the receiving antennas in the vicinity of the dielectric cylinder is obtained analytically. Then, we evaluate the influence of the infinite dielectric circular cylinder on the bit error rate (BER) performance for the digital communication using the ISM band of 915MHz and the UWB band. ©2010 IEEE.
  • Hayato Mizuno, Koichi Ito, Masaharu Takahashi, Kazuyuki Saito
    2010 IEEE International Symposium on Antennas and Propagation and CNC-USNC/URSI Radio Science Meeting - Leading the Wave, AP-S/URSI 2010 2010年  
    Implantable devices have been investigated with a great interest as communication tools. These implantable devices are embedded into the human or animal body. The vital information (e.g., glucose, blood pressure, and temperature) can be transmitted from implantable devices to the external equipments through wireless communication link [1]-[3]. Figure 1 shows a one of the application for a human in a sickroom. By using an implanted device, patient's events can be detected immediately. Then the implanted device sends the alert wirelessly to the home appliance which is connected to a hospital information system via a secured network link. A physician receives the alert and can decide to check back with the patient. In general, the implantable devices is have a bidirectional radio that can communicate with a paired radio carried within an external appliance. The external appliance could be a home monitoring device or a portable equipment, such as a cell phone, that provides the patient with increased mobility and a short-range wireless communication [4]. Therefore, the antenna for implanted devices is a key components in these telemetry systems. There are several issues to be considered in the design of an in-body antenna, including power consumption, size, frequency, biocompatibility, etc. This paper proposes an implanted helical folded dipole antenna for a short-range wireless communication at 2.45 GHz. Moreover, the implantable device is supposed to be embedded into human body using a syringe. According to this demand, the proposed antenna has a circular cylindrical shape of 1-mm diameter and 17.7-mm length. The antenna performances were investigated by use of the finite-difference timedomain (FDTD) calculation.
  • Kazuyuki Saito, Kousuke Tsubouchi, Masaharu Takahashi, Koichi Ito
    2010 Annual International Conference of the IEEE Engineering in Medicine and Biology Society, EMBC'10 2755-2758 2010年  
    Microwave thermal therapy is one of the modalities for cancer treatment. There are several schemes of microwave heating. The authors have been studying thin coaxial antenna for intracavitary microwave heating aiming at the treatment of bile duct carcinoma. Up to now, the heating characteristics of the antenna are investigated by numerical simulation and experiment for finding a possibility of the treatment. In this study, in order to consider practical situations of the treatment, heating characteristics of the antenna inserted into a metallic stent is evaluated by numerical simulations. Moreover, the relation between coagulation size of the tissue and the radiation power from the antenna is investigated experimentally. It must be considered, when the input power of the antenna is high (around several tens of watts). From these investigations, some useful results for practical treatments were found. © 2010 IEEE.
  • Ryohei Watanabe, Kazuyuki Saito, Soichi Watanabe, Masaharu Takahashi, Koichi Ito
    2010 Annual International Conference of the IEEE Engineering in Medicine and Biology Society, EMBC'10 3839-3842 2010年  
    Recently, electromagnetic interference (EMI) of an implanted pacemaker with a mobile phone was largely investigated. As for the pacemaker, the Japan National Authorities have recommended to keep the mobile phone in safe distance from the cardiac pacemaker. Meanwhile, evaluation of the interaction between the electromagnetic (EM) wave and human body was in progress. Therefore, the absorption of EM energy to the human body especially around the pacemaker, where the mobile phone was in a chest pocket of the pacemaker holder, was thoroughly evaluated. We provided the calculation of specific absorption rate (SAR) distributions around the pacemaker model that implanted into a rectangular parallelepiped torso model, when a mobile phone model is placed in the vicinity. In addition, the SAR was also experimentally performed to validate the such numerical calculations. We confirmed that SAR distributions could be estimated from the presence or absence of pacemaker model. Moreover, the measurement results of the SAR distribution suited to the calculation, thus its validation was achieved. © 2010 IEEE.
  • Yumiko Uno, Kazuyuki Saito, Masaharu Takahashi, Koichi Ito
    Proceedings - 2010 12th International Conference on Electromagnetics in Advanced Applications, ICEAA'10 406-409 2010年  査読有り
    This paper presents fundamental investigation of the validity of the homogeneous tissue-equivalent phantom which is simulated human tissue structures simply and is used in general experiment for evaluations of interaction between the human body and the antenna characteristics. In this paper, the dependence of antenna characteristics on structure of analytical model was investigated. Therefore the half wavelength dipole antenna and the loop antenna were arranged near a homogeneous model and a layer structural model, and the difference of antenna characteristics by structure of model was investigated. As a result, it was confirmed that the human tissue structure had a significant effect on the antenna characteristics when the distance between the antenna and the phantom is less than 0.1λ. In contrast, in case that the distance is more than 0.3λ, the validity of the homogeneous phantom was confirmed. ©2010 IEEE.
  • Takashi Nakajima, Masaharu Takahashi, Kazuyuki Saito, Koichi Ito
    International Conference on Applications of Electromagnetism and Student Innovation Competition Awards, AEM2C 2010 125-128 2010年  査読有り
    Recently, Radio Frequency Identification (RFID) systems have been widely developed. The wristband type RFID tag is one of the applications for personal identification. In this case, since the RFID antenna is in the vicinity of a human, the human body affects the antenna characteristics. Therefore, the analyses of the performances of the RFID antenna are required. In this paper, the antenna inside the wristband was numerically analyzed and measured using the layer structural arm model. As a result, characteristics of the antenna were clarified. ©2010 IEEE.
  • Hayato Mizuno, Masaharu Takahashi, Kazuyuki Saito, Koichi Ito
    Final Program and Book of Abstracts - iWAT 2010: 2010 International Workshop on Antenna Technology: Small Antennas, Innovative Structures and Materials 2010年  査読有り
    Small implanted devices have been investigated with great interest for wireless medical applications due to the promise of different clinical usages in order to promote patient's independence. In these implanted device systems, an antenna plays an important role as a part of transmitting and receiving power. Therefore, the research on the antenna for implantable device (implanted antenna) is important. In this study, we propose an implanted helical folded dipole antenna for short-range wireless communications. The antenna is designed to operate at 2.45 GHz, one of the industrial-scientific-medical (ISM) bands, and it is investigated by use of the finite-difference time-domain (FDTD) calculation. We have analyzed some performances of the proposed antenna and the results show that the proposed antenna can be a candidate as an implanted antenna. ©2010 IEEE.
  • Kazuyuki Saito, Kousuke Tsubouchi, Masaharu Takahashi, Koichi Ito
    Final Program and Book of Abstracts - iWAT 2010: 2010 International Workshop on Antenna Technology: Small Antennas, Innovative Structures and Materials 2010年  査読有り
    Microwave thermal therapy is one of the modalities for cancer treatment. There are several schemes of microwave heating. The authors have been studying thin coaxial antenna for intracavitary microwave heating aiming at the treatment of bile duct carcinoma. Up to now, the heating characteristics of the antenna are investigated by numerical simulation and experiment using a tissue-equivalent phantom. In this study, temperature rises around the antenna inserted into an actual liver tissue of swine are measured. As a result of the measurement, relation between effective heating region and input power to the antenna was found. ©2010 IEEE.
  • Takumi Hiraoka, Kazuyuki Saito, Masaharu Takahashi, Koichi Ito
    Final Program and Book of Abstracts - iWAT 2010: 2010 International Workshop on Antenna Technology: Small Antennas, Innovative Structures and Materials 2010年  査読有り
    Recently, mobile phones have been downsized increasingly and the antenna is embedded inside. In general, the characteristics of the antenna are influenced by a body of user. The influence of the hand on mobile phone is considered to be very important in designing the antenna. So far, the influence of the hand on the antenna has been investigated by use of a hand phantom, which has same electrical properties as the body and a particular shape. In this study, the authors have developed a hand phantom which can change its shape arbitrarily. Moreover, the S-parameter of the antenna gripped by the developed hand phantom was measured to show the effectiveness of the developed hand phantom. ©2010 IEEE.
  • Shimpei Akimoto, Tomoaki Nagaoka, Kazuyuki Saito, Soichi Watanabe, Masaharu Takahashi, Koichi Ito
    2010 ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY (EMBC) 734-737 2010年  査読有り
    Since the diversification of the electromagnetic (EM) environment is spreading, it is essential to estimate the EM energy absorption rate [specific absorption rate (SAR)] of a pregnant woman's body and her fetus under various exposure situations. For example, if pregnant women work in jobs where they might wear business portable radios around their abdomens, they should also be concerned about this issue, because the fetuses are in their abdomens. In this paper, in order to evaluate the SAR in the pregnant woman and her fetus when wearing the wireless radio terminal on her abdomen, the SAR distribution in the fetus is calculated using the numerical model of the pregnant woman by exposed to near-field of a normal mode helical antenna (NHA) with a metallic case at 150 MHz. In addition, the SAR in the fetus will be evaluated under two fetal positions. It was found that the fetal SARs are greatly affected by the distance and penetration path from the antenna to the fetal surface. In addition, the fetal SARs are lower than the RF safety guidelines for occupational exposure.
  • 高橋 応明
    電子情報通信学会 通信ソサイエティマガジン 2010(15) 15_81-15_81 2010年  
  • 壷内晃介, 齊藤一幸, 高橋応明, 伊藤公一, 露口利夫
    Thermal Medicine 25(Supplement) 2009年  
  • Nozomi Haga, Kazuyuki Saito, Masaharu Takahashi, Koichi Ito
    2009 IEEE International Workshop on Antenna Technology, iWAT 2009 2009年  
    Characteristics of antennas and propagation channels in on-body communications have been ascertained. Earlier studies indicated that not only maximization of path loss between body-mounted devises by use of monopolelike antennas but also countermeasures against fading by use of multi polarization antennas may be an important issue. Multi polarization can be obtained by perturbing the patch antennas. That is well known as circularly polarized patch antennas. In this paper, a perturbed patch antenna on a small ground plane in vicinity of the human body is characterized for some purposes such as challenge for co-existence of antenna and the human body rather than shutting out the body effects. Specifically, variation of input impedance, axial ratio, radiation efficiency, and radiation pattern of the antenna are evaluated by use of numerical calculation. ©2009 IEEE.
  • Koichi Ito, Nozomi Haga, Masaharu Takahashi, Kazuyuki Saito
    2009 IEEE International Workshop on Antenna Technology, iWAT 2009 2009年  
    In recent years, body-centric wireless communications become an active area of research due to their various applications such as e-healthcare, support systems for specialized occupations, and personal communications. Since the candidate frequencies for body-centric wireless communications widely range from MHz to GHz, dielectric properties of the human body tissues, relative dimensions of the human body to wavelength, and the propagation channels around the body extremely vary with frequencies. In this paper, to bring objective and unified idea on the frequency characteristics of body-centric wireless communication channels, electric field distributions around the human body wearing a small antenna in a wide frequency range of 2.5 MHz to 2.5 GHz are numerically calculated. The results show that behavior of the electric field distributions around the human body could be broadly divided into two ranges; below 100 MHz and above 250 MHz. ©2009 IEEE.
  • Basari, M. Fauzan Edy Purnomo, Kazuyuki Saito, Masaharu Takahashi, Koichi Ito
    European Conference on Antennas and Propagation, EuCAP 2009, Proceedings 1289-1292 2009年  
    This paper presents a simple antenna system for land vehicle communication aimed at Engineering Test Satellite-VIII (ETS-VIII) applications. The developed antenna system which mounted into a vehicle is compact, light weight and simple satellite-tracking operation. Owing to low profile, a patch array antenna, which includes onboard-power divider and switching circuit for antenna feeding control, is applied at such system. A Global Positioning System (GPS) receiver is constructed to provide accurate information on the vehicle's position and bearing during travelling. The personal computer (PC) interfaces as the control unit and data acquisition, which specifically designed for this application, allow the antenna beam-switching control as well as the retrieving of the received power levels. Measured results of the received power levels as well as the bit error rate performance for satellite-tracking are discussed.
  • Koichi Ito, Wei Xia, Masaharu Takahashi, Kazuyuki Saito
    European Conference on Antennas and Propagation, EuCAP 2009, Proceedings 718-721 2009年  
    Small implanted devices have been investigated with great interest for wireless medical applications due to the promise of different clinical usages in order to promote patient's independence. In these implanted device systems, an antenna plays an important role as a part of transmitting and receiving power. There are several issues to consider while designing an in-body antenna, including power consumption, size, frequency, bio compatibility, etc. In this study, we propose an implanted cavity slot antenna for short-rang wireless communications. The antenna is designed to operate at 2.45 GHz, one of the ISM (Industrial, Scientific, and Medical) bands, and is investigated by using the FDTD (Finite Difference Time Domain) calculation. The size of the proposed antenna is about 1 mm × 1 mm × 9 mm so that it will be easily embedded into the human body. We have analyzed some performances of the proposed antenna and the results show that the proposed antenna can be a candidate as an implanted antenna.
  • Basari, Kazuyuki Saito, Masaharu Takahashi, Koichi Ito
    APMC 2009 - Asia Pacific Microwave Conference 2009 1922-1925 2009年  
    This paper presents a field experiment of simple developed antenna system for land vehicle use which was tested by use of the Japanese geostationary test satellite called the Engineering Test Satellite-VIII (ETS-VIII). The antenna system was mounted in a vehicle is compact, light weight, and promising for low cost system. The antenna system was built by a planar array antenna which has a simple tracking capability controlled by a personal computer (PC) as the vehicle's bearing from a navigation system (Global Positioning System (GPS) receiver) is updated in real time. The GPS receiver was constructed to provide accurate information of the vehicle's position and bearing during traveling. The PC was used as the control unit and data acquisition allowing the antenna-beam control as well as the retrieving of the received power levels and error rate. The antenna system was thoroughly examined in the field experiment and satisfactory results were obtained. Steadily received power levels and bit error rate (BER) while tracking the ETS-VIII satellite were confirmed. Yet, the developed system was tested in real environment constraints such as buildings, foliages, utility poles and pedestrian overpasses. The results showed blockage was confirmed. Additionally, the satellite signal was steadily received even it was examined at the inclined-road. ©2009 IEEE.
  • 関 卓也, 齊藤 一幸, 高橋 応明, 伊藤 公一
    映像情報メディア学会技術報告 33 1-4 2009年  
    Ultra Wide Band(UWB)は,低消費電力でありながら,大容量通信が可能であるという他の通信システムにはない特徴をもっており,ホームネットワーク,Wireless Universal Serial Bus(WUSB)など様々な分野での利用が検討されている.今後UWB通信システムは,Wireless Body Area Network(WBAN)の標準化に伴い,人体近傍での利用が予想される.そこで筆者らは,日本国内においてUWB通信に認可されている7.25〜10.25GHzで動作する腕部装着型の広帯域アンテナを提案した.アンテナの装着位置は状況によって変化するため,本稿ではアンテナと腕部の間の距離を変えた際の入力インピーダンスおよび放射パターンを検討した.その結果,本アンテナは装着位置によって,入力インピーダンスが多少変化するものの,放射パターンの解析結果より,いずれの周波数においても,腕先端方向への通信に有利なことを確認した.
  • 高橋 応明
    電子情報通信学会 通信ソサイエティマガジン 2009(11) 11_1-11_1 2009年  
  • Katsuyuki Fujii, Daisuke Ishide, Masaharu Takahashi, Koichi Ito
    Kyokai Joho Imeji Zasshi/Journal of the Institute of Image Information and Television Engineers 62(12) 1980-1987 2008年12月  
    In recent years, a communications system, the Body Area Network, which uses the human body as a transmission path has attracted attention, and there is increasing expectation that it will be used more widely. However, there are still several points on the signal transmission mechanism of using the human body in this way that remain to be clarified, and there has been little research into the interaction of electromagnetic waves and the human body. Therefore, we used the Finite Difference Time Domain (FDTD) method to calculate the Efield distributions around simple and realistic models of the whole human body in free space with a weareble device. Moreover, E-field calculations were carried out when the positions of the body were changed. Our results show that using the simple homogeneous whole human body model is valid for the E-field calculation, and the dominant component of the E-field is normal to the body/air interface in all the positions that the human body assumes in daily life. Furthermore, in the state where the human body is shunted to the Earth ground, it was shown clearly that the E-field distribution is not mostly different from when a body is floating in free space. It can be concluded that these results provide useful information in improving the design of wearable devices.
  • 宇野 由美子, 齊藤 一幸, 高橋 応明, 伊藤 公一
    電子情報通信学会技術研究報告. A・P, アンテナ・伝播 108(241) 39-42 2008年10月9日  
    人体近傍で用いられる機器のアンテナの設計では,人体との相互作用の考慮が重要であり,その影響を評価する際には,人体の組織構造を簡易化した均質ファントムを用いた検討が一般的である.しかしながら,均質なモデルを用いることの妥当性の検討例は少ない.本稿では,人体の組織構造がアンテナ特性に与える影響の基礎的な検討として,半波長ダイポールアンテナを均質媒質モデルと層構造モデルの近傍に配置し,それらの構造の差異がアンテナ特性に与える影響について数値解析により検討した.その結果,アンテナをファントムから0.1λに配置した際の両モデルにおける差異は,入力インピーダンスは5Ω以上,放射効率は15%以上あるなど,アンテナ特性の差異が大きいことを確認した.
  • 野呂 崇徳, 高橋 応明, 伊藤 公一
    電子情報通信学会技術研究報告. A・P, アンテナ・伝播 108(201) 31-36 2008年9月11日  
    非励振素子付きパッチアンテナは非励振素子と励振パッチの複共振現象によりパッチアンテナを広帯域化する技術である.従来の非励振素子付きパッチアンテナは,励振パッチと非励振パッチの間隔によりリターンロスの帯域幅を変えることができる。筆者らは,パッチアンテナの低姿勢化の方法として,励振パッチと非励振パッチの間に二つのスロット開口を設け,このスロット開口の大きさによりアンテナを低姿勢化する方法を提案している.本報告では,スロット開口で結合した非励振素子付きパッチアンテナが広帯域特性を有する動作原理を等価回路モデルにより検討している.等価回路モデルのパラメータをS11のDelayから算出している.算出したパラメータによると,スロット開口を小さくすることにより励振パッチと非励振パッチの電磁的結合度が減少することがわかった.スロット開口で結合した非励振素子付きパッチアンテナは,スロット開口の大きさで電磁的結合度の制御することが可能であり,その結合度に応じてリターンロスの帯域幅を設定することが可能であることを示した.
  • 関 卓也, 齊藤 一幸, 高橋 応明, 伊藤 公一
    電子情報通信学会ソサイエティ大会講演論文集 2008(1) 77-77 2008年9月2日  
  • 秋元 晋平, 長岡 智明, 菊池 悟, 齊藤 一幸, 渡辺 聡一, 高橋 応明, 伊藤 公一
    電子情報通信学会ソサイエティ大会講演論文集 2008(1) 266-266 2008年9月2日  
  • 宇野 由美子, 齊藤 一幸, 高橋 応明, 伊藤 公一
    電子情報通信学会ソサイエティ大会講演論文集 2008(1) 273-273 2008年9月2日  
  • 野呂 崇徳, 高橋 応明, 伊藤 公一
    電子情報通信学会ソサイエティ大会講演論文集 2008(1) 94-94 2008年9月2日  
  • 関 卓也, 齊藤 一幸, 高橋 応明, 伊藤 公一
    電子情報通信学会技術研究報告. A・P, アンテナ・伝播 108(148) 81-86 2008年7月16日  
    UWB (Ultra Wide Band)は,現在,ワイヤレスUSB(Universal Serial Bus),測距レーダなど様々な分野での利用が検討されている.今後は,WBAN (Wireless Body Area Network)の標準化に伴い,人体近傍でも使用されることが予想される.そこで筆者らは,日本国内において,DAA (Detect And Avoid)技術を付加しなくてもよい7.25〜10.25GHzで動作する人体腕部装着型の小型UWBアンテナを提案した.本報告では,アンテナの特徴を近傍界・遠方界の両面から考察すべく,電界強度分布と放射パターンを検討した.その結果,このアンテナは腕先端方向への通信に有利なこと,発生する電界は人体に垂直な成分が支配的であることを確認した.以上のことから,今回提案したアンテナは,人体腕部装着型UWBアンテナとして,十分に有用である.

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