2021/10/11 更新

写真a

フジモリ カズヒロ
藤森 和博
FUJIMORI Kazuhiro
所属
自然科学学域 准教授
職名
准教授
外部リンク

学位

  • 博士(工学) ( 横浜国立大学 )

研究キーワード

  • 無線電力伝送

  • マイクロ波工学

  • アンテナ・電波伝搬

  • Wireless Power Transfer

  • Microwave Engineering

  • Antennas & Propagation

研究分野

  • ものづくり技術(機械・電気電子・化学工学) / 電子デバイス、電子機器

  • ものづくり技術(機械・電気電子・化学工学) / 通信工学

学歴

  • 横浜国立大学    

    - 1994年

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    国名: 日本国

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  • 横浜国立大学   Faculty of Engineering   Division of Electrical and Computer Engineering

    - 1994年

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所属学協会

 

書籍等出版物

  • Solor Power Satellite/Station "jointly worked"

    Ohmsya Co.,Ltd.  2012年  ( ISBN:9784274212338

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  • 宇宙太陽発電(共著)

    オーム社  2012年  ( ISBN:9784274212338

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  • ワイヤレス給電技術の最前線(共著)

    シーエムシー出版  2011年  ( ISBN:9784781305233

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  • Frontiers of Wireless Power Transmission Technologies "jointly worked"

    CMC Publishing Co.,Ltd.  2011年  ( ISBN:9784781305233

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  • Fundamentals and applications of MEMS/NEMS Engineering "jointly worked"

    Techno system  2009年 

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  • MEMS/NEMS工学全集(共著)

    テクノシステム  2009年 

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▼全件表示

MISC

  • Selective electroless plating of 3D-printed plastic structures for three-dimensional microwave metamaterials

    Atsushi Ishikawa, Taiki Kato, Nobuyuki Takeyasu, Kazuhiro Fujimori, Kenji Tsuruta

    APPLIED PHYSICS LETTERS   111 ( 18 )   921 - 926   2017年10月

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    記述言語:英語   出版者・発行元:AMER INST PHYSICS  

    A technique of selective electroless plating onto PLA-ABS (Polylactic Acid-Acrylonitrile Butadiene Styrene) composite structures fabricated by three-dimensional (3D) printing is demonstrated to construct 3D microwave metamaterials. The reducing activity of the PLA surface is selectively enhanced by the chemical modification involving Sn2+ in a simple wet process, thereby forming a highly conductive Ag-plated membrane only onto the PLA surface. The fabricated metamaterial composed of Ag-plated PLA and non-plated ABS parts is characterized experimentally and numerically to demonstrate the important bi-anisotropic microwave responses arising from the 3D nature of metallodielectric structures. Our approach based on a simple wet chemical process allows for the creation of highly complex 3D metal-insulator structures, thus paving the way toward the sophisticated microwave applications of the 3D printing technology. Published by AIP Publishing.

    DOI: 10.1063/1.4986203

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  • アルカリ金属を用いた交流磁界の光学検出 ~市販の磁界テスタとの比較と永久磁石を用いたプローブ化の検討~

    田上周路, 篠原 優, 豊田啓孝, 藤森和博, 深野秀樹

    電子情報通信学会 論文誌   J100-B ( 3 )   158 - 165   2017年

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  • Terahertz acoustic wave on piezo-electric semiconductor film via large-scale molecular dynamics simulation

    R. Hikata, K. Tsuruta, A. Ishikawa, K. Fujimori

    Japanese Journal of Applied Physics   54 ( 7S1 )   07HB07-1-07HB07-4   2015年

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  • Optically Pumped Alkali-Metal Atomic Magnetometer using Permanent Magnets for AC Magnetic Field Detection

    Shuji Taue, Masaru Shinohara, Takayuki Nagaoka, Yoshitaka Toyota, Kazuhiro Fujimori, Hideki Fukano

    Proceedings of the Eighth 2015 Korea-Japan Joint Conference on EMT/EMC/BE   2015年

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  • Phononic-Crystal Acoustic Lens by Design for Energy-Transmission Devices

    Yusuke Kanno, Kenji Tsuruta, Kazuhiro Fujimori, Hideki Fukano, Shigeji Nogi

    ELECTRONICS AND COMMUNICATIONS IN JAPAN   97 ( 1 )   22 - 27   2014年1月

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    記述言語:英語   出版者・発行元:WILEY-BLACKWELL  

    The lens effect of acoustic waves in a two-dimensional (2D) phononic crystal is studied by numerical simulation based on the finite-difference time-domain (FDTD) method. We calculate the phonon band structure of 2D phononic crystals, consisting of metal/ceramic cylinders placed periodically in water. The lens effect is observed for the far-field wave in phononic crystals with two-layered and graded-index structure. We compare the focal intensity and the energy transmission efficiency in these numerical experiments, and show that a novel energy-transmission device can be designed using phononic crystals. (c) 2013 Wiley Periodicals, Inc. Electron Comm Jpn, 97(1): 22-27, 2014; Published online in Wiley Online Library (wileyonlinelibrary.com). DOI 10.1002/ecj.11491

    DOI: 10.1002/ecj.11491

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  • Design and Visualization of Ultrasonic Wave in Phononic Structure for Efficient Energy Transmission

    Kazuya Tsubouchi, Atsushi Ishikawa, Kazuhiro Fujimori, Kenji Tsuruta

    Proceedings of the 35th Symposium on UltraSonic Electronics   35   225 - 226   2014年

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  • Terahertz Acoustic Wave on Piezoelectric Semiconductor Film via Large-Scale Molecular Dynamics Simulation

    Ryo Hikata, Kenji Tsuruta, Atsushi Ishikawa, Kazuhiro Fujimori

    Proceedings of Symposium on Ultrasonic Electronics   35   401 - 402   2014年

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  • Ferroelectric Domain Contribution to the Tunability of Ba0.8Sr0.2TiO3 Ceramics

    Takashi Teranishi, Tsuyoshi Sogabe, Hidetaka Hayashi, Akira Kishimoto, Kazuhiro Fujimori

    JAPANESE JOURNAL OF APPLIED PHYSICS   52 ( 9 )   09KF06-1-09KF06-5   2013年9月

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    記述言語:英語   出版者・発行元:IOP PUBLISHING LTD  

    Polarization contributions to the tunable properties of Ba0.8Sr0.2TiO3 ceramics were quantitatively studied by microwave measurements. The width of the ferroelectric domain walls (90 degrees domain walls) decreased with decreasing average grain size. The variation in domain size with grain size for grains smaller than 10 mu m was roughly proportional to the square root of the grain size, consistent with previous reports on BaTiO3. The smaller size of the 90 degrees domains (i.e., higher domain-wall density) resulted in greater tunability at an applied DC electric field of 6.7 kV/cm. The tunability of the specimen with a domain size of 161 nm was 26.5%, which was 4.4 times that of the specimen with a domain size of 259 nm (T = 6.0%). Under a relatively low DC field, the density of the domain-wall motion was the dominant factor determining the overall tunable properties, while the contributions of the ionic and electronic polarizations were relatively small in Ba0.8Sr0.2TiO3. (C) 2013 The Japan Society of Applied Physics

    DOI: 10.7567/JJAP.52.09KF06

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  • Design and development of highly ecient transducer for ultrasonic wireless power transmission system

    Yuki Hori, Kazuhiro Fujimori, Kenji Tsuruta, Shigeji Nogi

    ELECTRICAL ENGINEERING IN JAPAN   184 ( 3 )   27 - 35   2013年8月

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    記述言語:英語   出版者・発行元:WILEY-BLACKWELL  

    In this paper, a transducer that is suitable for the ultrasonic wireless power transmission system is discussed. The transducer is designed based on Mason's equivalent circuit theory, basically. The transducer was developed using design parameters optimized by multiphysics analysis. As a result, it is confirmed that the transmission eciency is drastically improved to more than 50%. This result suggests that wireless power transmission by acoustic wave is feasible. (c) 2013 Wiley Periodicals, Inc. Electr Eng Jpn, 184(3): 2735, 2013; Published online in Wiley Online Library (wileyonlinelibrary.com). DOI 10.1002/eej.22406

    DOI: 10.1002/eej.22406

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  • Quasi-millimeter-wave absorption behavior in Y/Yb-stabilized zirconia ceramics

    Takashi Teranishi, Naoki Akiyama, Keiko Ayano, Hidetaka Hayashi, Akira Kishimoto, Kazuhiro Fujimori, Takuya Hoshina, Hiroaki Takeda, Takaaki Tsurumi

    APPLIED PHYSICS LETTERS   100 ( 24 )   242903-1-242903-4   2012年6月

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    記述言語:英語   出版者・発行元:AMER INST PHYSICS  

    Broadband dielectric spectra from 10 to 10(14) Hz were acquired for 8 mol. % Y2O3/Yb2O3-stabilized zirconia (8YSZ and 8YbSZ) ceramics that related the dipole and ionic polarization losses to the absorption efficiency of electromagnetic irradiation. For 24 GHz irradiation, 8YSZ exhibited a higher absorption efficiency than 8YbSZ, resulting in a higher dielectric loss. The difference in the dielectric loss was interpreted as the difference in the loss of the dipoles originating from the fluctuations in the defect associations (Y'(Zr)Vo and Yb'(Zr)Vo). (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4729147]

    DOI: 10.1063/1.4729147

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  • Complex Conductivity Using Wideband Spectroscopy for Yttria/Ytterbia-Stabilized Zirconia Ceramics

    Takashi Teranishi, Kosuke Shimizu, Naoki Akiyama, Hidetaka Hayashi, Akira Kishimoto, Kazuhiro Fujimori

    JAPANESE JOURNAL OF APPLIED PHYSICS   51 ( 1 )   011102-1-011102-4   2012年1月

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    記述言語:英語   出版者・発行元:JAPAN SOC APPLIED PHYSICS  

    Complex conductivity wideband spectra from 10(-1) to 10(14) Hz (100 THz) were determined for 8 mol% yttria-stabilized zirconia (8YSZ) and 8 mol% ytterbia-stabilized zirconia (8YbSZ) ceramics. The contributions of electrolyte-electrode interfaces, grain boundaries, intragrain ion-hopping, and optical phonons were quantified to relate the microscopic conduction behavior to the overall conductivity. Intrinsic conductivity was mostly governed by ion-hopping. For both 8YSZ and 8YbSZ, ion-hopping followed the universal dielectric response (UDR) for broadband frequencies except for the phonon dispersion frequencies. The higher overall conductivities of the 8YbSZ ceramics compared to the 8YSZ ones were attributed to differences in the UDR contributions. The dominant factor determining the difference in the intrinsic conductivity in broadband frequencies from direct current (DC) to microwave between the 8YSZ and 8YbSZ ceramics was the DC conductivity due to UDR, sigma(dc), where sigma(dc(8YbSZ)) > sigma(dc(8YSZ)). Other parameters in the UDR and the optical parameters did not greatly influence the intrinsic conductivities. (C) 2012 The Japan Society of Applied Physics

    DOI: 10.1143/JJAP.51.011102

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  • An Investigation for Optimum Design of Matching Circuit in Highly Efficient RF-DC Conversion Circuit by Genetic Algorithm "jointly worked"

    Y.Kondo, K.Fujimori, K.Tsuruta

    Proc. 2012 International Symposium on Antennas and Propagation   194 - 197   2012年

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  • 超音波無線電力伝送のための高効率なトランスデューサの設計と開発(共著)

    堀祐貴, 藤森和博, 鶴田健二, 野木茂次

    電気学会論文誌C   132 ( 3 )   337 - 343   2012年

  • Design and Development of Highly Efficient Transducer for Ultrasonic Wireless Power Transmission System "jointly worked"

    Y.Hori, K.Fujimori, K.Tsuruta, S.Nogi

    132 ( 3 )   337 - 343   2012年

  • 超音波エネルギー伝送デバイスを目指したフォノニック結晶による音響レンズの設計(共著)

    菅野祐輔, 鶴田健二, 藤森和博, 深野秀樹, 野木茂次

    電気学会論文誌C   132 ( 5 )   686 - 690   2012年

  • Phononic-crystal acoustic lens by design for energy-transmission devices

    Yusuke Kanno, Kenji Tsuruta, Kazuhiro Fujimori, Hideki Fukano, Shigeji Nogi

    IEEJ Transactions on Electronics, Information and Systems   132 ( 5 )   686 - 690   2012年

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    記述言語:英語   出版者・発行元:Institute of Electrical Engineers of Japan  

    Lens effect of acoustic wave in two-dimensional (2D) phononic crystal is studied by numerical simulation based on the finite-difference time-domain (FDTD) method. We calculate the phonon band structure of 2D phononic crystals, consisting of metal/ceramic cylinders placed periodically in water. Lens effect is observed for far-field wave in the phononic crystals with two-layered and graded-index structure. We compare the focal intensity and the energy transmission efficiency in these numerical experiments, and show that a novel energy-transmission device can be designed using phononic crystals. © 2012 The Institute of Electrical Engineers of Japan.

    DOI: 10.1541/ieejeiss.132.686

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  • Frequency Characteristic of Transmission Efficiency Dependent on Matching Condition of Transducer in Ultrasonic Wireless Power Transmission System "jointly worked"

    K.Fujimori, S.Tominaga, K.Tanda, K.Tsuruta, S.Nogi

    Proc. 2012 International Symposium on Antennas and Propagation   166 - 169   2012年

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  • Characteristic of RF-DC Conversion Circuit for Wireless Power Transmission using the Low Resistance GaN Schottky Barrier Diode "jointly worked"

    K.Fujimori

    Proc. 2012 International Symposium on Antennas and Propagation   190 - 193   2012年

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  • Negative Refraction and Energy-Transmission Efficiency of Acoustic Waves in Two-Dimensional Phononic Crystal: Numerical and Experimental Study

    Yuuki Kasai, Kenji Tsuruta, Kazuhiro Fujimori, Hideki Fukano, Shigeji Nogi

    JAPANESE JOURNAL OF APPLIED PHYSICS   50 ( 6 )   2011年6月

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    記述言語:英語   出版者・発行元:JAPAN SOC APPLIED PHYSICS  

    The negative refraction of acoustic waves in a two-dimensional phononic-crystal slab is studied by numerical simulation based on the finite-difference time-domain (FDTD) method and by ultrasonic measurement. The incident-angle dependences of energy-transmission efficiency in the simulation and experiment are in good agreement in the frequency range of approximately 1.2 MHz. Using the FDTD method, we optimize the efficiency by varying structural parameters such as filling fraction and slab thickness. The effect of deviation from the ideal crystallinity is also evaluated quantitatively via the simulation. These results indicate that an energetically efficient acoustic lens can be fabricated by carefully optimizing the structure of the phononic crystal. (C) 2011 The Japan Society of Applied Physics

    DOI: 10.1143/JJAP.50.067301

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  • Acoustic lens using sonic crystal for energy-transmission application

    Y. Kanno, Y. Kasai, K. Tsuruta, K. Fujimori, H. Fukano, S. Nogi

    2011 IEEE MTT-S International Microwave Workshop Series on Innovative Wireless Power Transmission: Technologies, Systems, and Applications, IMWS-IWPT 2011 - Proceedings   207 - 210   2011年

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    記述言語:英語  

    We design and characterize a two-dimensional sonic crystal (SC) to manipulate the propagation of acoustic waves by numerical simulation based on the finite-difference time-domain (FDTD) method and by ultrasonic measurement. Two types of SC for an acoustic lens effect are studied. One is a homogeneous periodic structure exhibiting negative refraction, and the other has a hetero-structure. Negative refraction behavior in the simulation is good agreement with the experiment in the frequency range around 1.2MHz. We also observe a lens effect for far-field wave in the hetero-structured SC. These results indicate that a novel energy-transmission/harvesting device can be designed using SCs. © 2011 IEEE.

    DOI: 10.1109/IMWS.2011.5877131

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  • Development of highly efficient transducer for wireless power transmission system by ultrasonic

    Yusuke Shigeta, Yuki Hori, Kazuhiro Fujimori, Kenji Tsuruta, Shigeji Nogi

    2011 IEEE MTT-S International Microwave Workshop Series on Innovative Wireless Power Transmission: Technologies, Systems, and Applications, IMWS-IWPT 2011 - Proceedings   171 - 174   2011年

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    記述言語:英語  

    We developed a fundamental testbed and investigated the suitable transducer for the wireless power transmission (WPT). We also reported experimental results of the transmission efficiency in water by using the commercial transducer (COM) which only designed to match to the acoustic impedance of water and the electric impedance of the transmitter and receiver. In this paper, we investigate the transducer for improving the efficiency based on the Mason's equivalent circuit. For deciding a structure and materials of the transducer, we used ANSYS well-known as the multi-physics simulator. In this result, it is confirmed that the transmission efficiency is drastically improved from less than 1% to 60%. In addition, we made designed transducer, and confirmed the systems' efficiency is about 50 %. This result suggests that the WPT by acoustic wave is practicable. © 2011 IEEE.

    DOI: 10.1109/IMWS.2011.5877115

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  • 導波管ポートと同軸線路ポートをもつ回路素子の散乱行列の未知スルー校正法を用いた測定(共著)

    佐薙稔, 藤森和博, 野木茂次

    電子情報通信学会論文誌(C)   J94-C ( 12 )   487 - 495   2011年

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  • Design of Anti-Resonance Transducer and its Abilities for Efficient Ultrasonic Wireless Power Transmission System "jointly worked"

    Y.Hori, Y.Shigeta, K.Fujimori, K.Tsuruta, S.Nogi

    The 41st European Microwave Conference   67 - 70   2011年

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  • The Influences of Diode Parameters on Conversion Efficiency of RF-DC Conversion Circuit for Wireless Power Transmission System

    Kazuhiro Fujimori, Sho-ichi Tamaru, Kenji Tsuruta, Shigeji Nogi

    2011 41ST EUROPEAN MICROWAVE CONFERENCE   57 - 60   2011年

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    記述言語:英語   出版者・発行元:IEEE  

    RF-DC conversion circuit is one of the most important components in the wireless power transmission technologies. For realizing highly efficient wireless power transmission, it is necessary to design the RF-DC conversion circuit with high conversion efficiency, and the designing method of the circuit is actively studied. In this paper, the influences of diode parameters, such as its resistance, junction capacitance, parasitic reactance, and so on, on the conversion efficiency of the RF-DC conversion circuit are investigated to clarify the characteristic of the diode for obtaining highly efficient RF-DC conversion circuit.

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  • Efficiency and harmonics generation in microwave to DC conversion circuits of half-wave and full-wave rectifier types

    Shohei Imai, Shoichi Tamaru, Kazuhiro Fujimori, Minoru Sanagi, Shigeji Nogi

    2011 IEEE MTT-S International Microwave Workshop Series on Innovative Wireless Power Transmission: Technologies, Systems, and Applications, IMWS-IWPT 2011 - Proceedings   15 - 18   2011年

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    記述言語:英語  

    A Rectifying Antenna (Rectenna) is one of the most important components for a wireless power transmission. It has been developed for many applications such as Space Solar Power System (SSPS), and Radio Frequency Identification (RFID) etc. The Rectenna consisting of RF-DC conversion circuits and receiving antennas needs to be designed for high conversion efficiency to achieve efficient power transmission. we try to design the mw-Class RF-DC conversion circuit using half-and full-wave rectification. The measured conversion efficiencies is 59.3 % and 65.3 % athalf- and full-wave type, respectively. And the full-wave type has lower 2nd harmonic reflection coefficient. © 2011 IEEE.

    DOI: 10.1109/IMWS.2011.5877081

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  • RF to DC Conversion for Wireless Power Transmission

    Shigeji Nogi, Kazuhiro Fujimori, Minoru Sanagi

    The IEICE Transactions on Electronics   J93-C ( 12 )   540 - 548   2010年

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  • Design of Highly Efficient and Compact RF-DC Conversion Circuit at mW-class by LE-FDTD Method(共著)

    Tsunayuki Yamamoto, Kazuhiro Fujimori, Minoru Sanagi, Shigeji Nogi

    The IEICE Transactions on Electronics   E93-C ( 8 )   1323 - 1332   2010年

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  • An Important Relation for Determining A High-Efficiency RF–DC Conversion Circuit(共著)

    Shohei Imai, Kazuhiro Fujimori, Minoru Sanagi, Shigeji Nogi

    2010 Asia-Pacific Microwave Conference   2319 - 2322   2010年

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    記述言語:英語  

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  • 無線電力伝送におけるRF-DC変換(共著)

    野木茂次, 藤森和博, 佐薙稔

    電子情報通信学会誌   J93-C ( 12 )   540 - 548   2010年

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  • Efficient antenna miniaturization technique by cut off of chromosome-length in genetic algorithm(共著)

    Tsunayuki YAMAMOTO, Kazuhiro FUJIMORI, Minoru SANAGI, Shigeji NOGI, Takuya TSUKAGOSHI

    2009 Asia-Pacific Microwave Conference   2009年

  • The Fundamental Design Approach of The RF-DC Conversion Circuit for Optimizing Its Characteristics

    Tsunayuki Yamamoto, Kazuhiro Fujimori, Minoru Sanagi, Shigeji Nogi

    2008 EUROPEAN MICROWAVE INTEGRATED CIRCUITS CONFERENCE (EUMIC)   370 - 373   2008年

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    記述言語:英語   出版者・発行元:IEEE  

    A Rectifying Antenna (Rectenna) is one of the most important components for a wireless power transmission. It has been developed for many applications such as Space Solar Power System (SSPS), Radio Frequency IDentification (RF-ID), and electric vehicle etc. The Rectenna consisting of RF-DC conversion circuits and receiving antennas needs to be designed for high conversion efficiency to achieve efficient power transmission. In this paper, we investigated the RF-DC conversion circuits by the theoretical analysis. And, we propose the theoretical formula for calculating the output DC voltage in giving the input voltage. The result that is calculated by the formula agreed with the simulator's result, so, we confirmed the validity of the formula we derived. The theory and the formula we derived are useful in order to know the basic operation of the RF-DC conversion circuit, and to design the circuit efficiently.

    DOI: 10.1109/EMICC.2008.4772306

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  • Dispersionless Phase Responses of Pseudoperiodic Metamaterials based on CRLH Transmission Lines

    Takuya Tsukagoshi, Kazuhiro Fujimori, Minoru Sanagi, Shigeji Nogi

    2008 Asia-Pacific Microwave Conference   2008年

  • Design of RF-DC Conversion Circuit Composed of Chip Devices

    Tsunayuki Yamamoto, Kazuhiro Fujimori, Minoru Sanagi, Shigeji Nogi

    2008 Asia-Pacific Microwave Conference   2008年

  • Controlling Phase Responses with Pseudoperiodic Metamaterials based on Composite Right-Left Handed Transmission Lines

    Takuya Tsukagoshi, Kazuhiro Fujimori, Minoru Sanagi, Shigeji Nogi

    38th European Microwave Conference   1238 - 1241   2008年

  • An efficient LE-FDTD method for the analysis of the active integrated circuit and antenna mounted non-linear devices

    Kazuhiro Fujimori, Naoto Kawashima, Minoru Sanagi, Shigeji Nogi

    IEICE TRANSACTIONS ON ELECTRONICS   E90C ( 9 )   1776 - 1783   2007年9月

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    記述言語:英語   出版者・発行元:IEICE-INST ELECTRONICS INFORMATION COMMUNICATIONS ENG  

    The trend of microwave circuits has been toward highly integrated systems. Most design tools for designing microwave circuits mounted the linear or the nonlinear devices adopt the fundamental circuit theory using the S matrix on the frequency domain. The harmonic balance method is also used to correspond to the nonlinear circuit. Therefore, the effect of the electromagnetic field, for example, a mutual coupling between sub-circuits through the, space is almost disregarded. To calculate these circuits included its surrounding electromagnetic field, the finite difference time domain method combined with the equivalent circuit simulation had been presented as the lumped element FDTD (LE-FDTD) method. In general, even if an analytical target is a linear circuit, the FDTD method requires very long analytical time. In this paper, we propose an efficient LE-FDTD method to reduce the analytical time. We investigate its efficiency to compare with the conventional LE-FDTD method or measurements, consequently, it is confirmed that the proposal method requires only at analytical time of 1/10 compared with the conventional method. We also show that the proposal method is able to analyze characteristics of the active integrated antenna (AIA) which are practicably impossible to analyze by using the conventional method.

    DOI: 10.1093/ietele/e90-c.9.1776

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  • The mW-class High Efficient RF-DC Conversion Circuit using the Resonance Structure

    Tsunayuki Yamamoto, Kazuhiro Fujimori, Minoru Sanagi, Shigeji Nogi

    International Symposium on Antennas and Propagation   660 - 663   2007年

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  • Injection signal controlled active phased arrays without mode jumps

    Minoru Sanagi, Kazuhiro Fujimori, Shigeji Nogi

    ELECTRONICS AND COMMUNICATIONS IN JAPAN PART II-ELECTRONICS   90 ( 4 )   34 - 45   2007年

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    記述言語:英語   出版者・発行元:SCRIPTA TECHNICA-JOHN WILEY & SONS  

    An examination is made of phased array operation, by injecting signals with different phases into both ends of a coupled microwave oscillator system and controlling that phase, as a system for an active phased array antenna using frequency locking. This system has multiple operating modes, but by causing a slight deviation of only the free-running frequency of the end oscillator from the frequency of the injection signal, mode jumps can be suppressed and the phase difference between the oscillators made large. The effectiveness of this method can be numerically confirmed by finding the conditions for single mode operation with an approximation analysis of the governing equation. Using an active integrated antenna constructed of a patch antenna and serial-feedback FET oscillators, an experiment was performed by scanning the radiation beams of two-, three-, and five-element antenna arrays to demonstrate that the scan range in the radiation direction was extended with single mode operation. (C) 2007 Wiley Periodicals, Inc.

    DOI: 10.1002/ecjb.20293

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  • The design of mw-class RF-DC conversion circuit using the full-wave rectification

    Tsunayuki Yamamoto, Kazuhiro Fujimori, Minoru Sanagi, Shigeji Nogi

    2007 EUROPEAN MICROWAVE CONFERENCE, VOLS 1-4   905 - 908   2007年

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    記述言語:英語   出版者・発行元:IEEE  

    A Rectifying Antenna (Rectenna) is one of the most important components for a wireless power transmission. It has been developed for many applications such as Space Solar Power System (SSPS), and Radio Frequency Identification (RFID) etc. The Rectenna consisting of RF-DC conversion circuits and receiving antennas needs to be designed for high conversion efficiency to achieve efficient power transmission. In this paper, we try to design the mw-Class RF-DC conversion circuit using full-wave rectification.

    DOI: 10.1109/EUMC.2007.4405340

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  • A novel extended FDTD method for the analysis of the active integrated circuit and antenna mounted non-linear devices

    Naoto Kawashima, Kazuhiro Fujimori, Minoru Sanagi, Shigeji Nogi

    Asia-Pacific Microwave Conference Proceedings, APMC   2   953 - 956   2006年

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    記述言語:英語  

    The trend of microwave circuits has been toward highly integrated systems. Most design tools for circuits are based on the fundamental circuit theory using the S matrix combined with the harmonic-balance method. Consequently, the electromagnetic effect is ignored or approximated at best. Therefore, the extended finite-difference time-domain(FDTD) method combined with the equivalent circuit simulation had been presented. However, it takes very long times to analyze any circuits. In this paper, we propose a novel extended FDTD method to reduce calculation resources. We investigate its efficiency to compare with the conventional extended FDTD method or measurements, consequently, it is confirmed that the proposal method is required calculation resources less than 10% compared with the conventional method. We also show that the proposal method is able to analyze characteristics of the active integrated antenna(AIA) which are practicably impossible to analyze by using the conventional method. Copyright 2006 IEICE.

    DOI: 10.1109/APMC.2006.4429570

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  • Efficient design approach of mW-class RF-DC conversion rectenna circuits by FDTD analysis

    Tatsuya Takagaki, Tsunayuki Yamamoto, Kazuhiro Fujimori, Minoru Sanagi, Shigeji Nogi

    Asia-Pacific Microwave Conference Proceedings, APMC   3   1945 - 1948   2006年

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    記述言語:英語   出版者・発行元:Institute of Electrical and Electronics Engineers Inc.  

    A Rectenna is one of the most important components for a wireless power transmission. It has been developed for many applications such as Space Solar Power System (SSPS), and RFID etc. The rectenna consisting of RF-DC conversion circuits and receiving antennas needs to be designed for high conversion efficiency to achieve efficient power transmission. In this paper, the extended FDTD method is proposed as a method for calculating the RF-DC conversion circuit, and the availability of this method is confirmed. Furthermore, the output power from the circuit including the radiation power is investigated. Copyright 2006 IEICE.

    DOI: 10.1109/APMC.2006.4429790

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  • Efficient Design Approach of RF-DC Conversion Circuit Including Undesirable Radiation

    Tatsuya Takagaki, Tsunayuki Yamamoto, Kazuhiro Fujimori, Minoru Sanagi, Shigeji Nogi

    International Symposium on Antennas and Propagation   2006年

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  • FDTD Analysis cosidered Undesirable Radiation of RF-DC Conversion Circuit for Microwave Power Transmission System

    Kazuhiro FUJIMORI, Tatsuya TAKAGAKI, Tsunayuki YAMAMOTO, Minoru SANAGI, Shigeji NOGI

    Korea-Japan Joint Conference on AP/EMCJ/EMT   2006年

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  • 電圧制御能動集積パッチアンテナの発振モードの単一化

    佐薙稔, 平田務, 藤森和博, 野木茂次

    電子情報通信学会論文誌   2006年

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  • 注入同期制御型能動フェーズドアレーの動作モードの単一化

    佐薙稔, 藤森和博, 野木茂次

    電子情報通信学会論文誌   2006年

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  • Active phased array antenna radiating second harmonic output wave

    M Sanagi, K Yano, K Fujimori, S Nogi

    ELECTRONICS AND COMMUNICATIONS IN JAPAN PART II-ELECTRONICS   89 ( 4 )   39 - 50   2006年

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    記述言語:英語   出版者・発行元:SCRIPTA TECHNICA-JOHN WILEY & SONS  

    In order to make the scanned radiation beam range wider, phased array operation of an active antenna radiating the second harmonic is studied. By numerical analysis of a coupled oscillator system modeling file active antenna array, it is shown that the variation of the phase difference of the second harmonic component between the oscillators reaches 2 pi when the oscillators are coupled only by the fundamental components. This value is twice that yielding the fundamental component. Through experiments using two- and four-element arrays, the results of the analysis are confirmed. The radiation beam of the second harmonic is successfully scanned in a wider range than that for the fundamental component. (c) 2006 Wiley Periodicals, Inc.

    DOI: 10.1002/ecjb.20168

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  • Active integrated antenna techniques for beam control

    S Nogi, M Sanagi, K Fujimori

    IEICE TRANSACTIONS ON ELECTRONICS   E88C ( 7 )   1358 - 1367   2005年7月

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    記述言語:英語   出版者・発行元:IEICE-INST ELECTRONICS INFORMATION COMMUNICATIONS ENG  

    Active integrated antenna techniques have high potential for giving smaller size, lighter weight, lower cost and higher efficiency, in particular to millimeter-wave circuit-antenna systems. This paper gives a review of active integrated antenna techniques with emphasis on beam steering and retrodirective antenna arrays. Various beam steering operations of integrated antenna oscillator arrays using locking phenomena are presented. Beam steering arrays of such type have the feature that phase shifters are not necessary in the arrays. Arrays with higher harmonic output radiation can enlarge the beam steering range. Arrays of locked active antennas which operate as self-oscillating mixers can be beam controllable receiving antennas.

    DOI: 10.1093/ietele/e88-c.7.1358

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  • Beam control in unilaterally coupled active antennas with self-oscillating harmonic mixers

    M Sanagi, J Fujiwara, K Fujimori, S Nogi

    IEICE TRANSACTIONS ON ELECTRONICS   E88C ( 7 )   1375 - 1381   2005年7月

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    記述言語:英語   出版者・発行元:IEICE-INST ELECTRONICS INFORMATION COMMUNICATIONS ENG  

    Beam control using active antenna arrays with selfoscillating harmonic mixers has been investigated. The active antenna is composed of a patch antenna receiving RF signal and a parallel feedback type oscillator which operates as the self-oscillating harmonic mixer, and down-converts the received RF signal into IF signal. The mixer has two ports for local oscillating (LO) signal. One is an output port extracting the LO signal. The other is an input port for an injection signal to synchronize the local oscillation. The mixers can be coupled unilaterally without other nonreciprocal components by connecting the output port to the input port in the next mixer. In the unilaterally coupled array, the phase differences of the LO signals between the adjacent mixers can be varied without phase shifters in injection locking state by changing the local free-running frequencies of the self-oscillating mixers. The receiving pattern can be controlled by combining the IF signals from the individual active antennas, which have phases associated with the LO signals. The IF is difference between the RF and double of the LO frequency so that arbitrary phase differences from 0 to 2 pi radian can be provided to the output IF signals. The experiments using the two- and three-element arrays demonstrated beam control capability.

    DOI: 10.1093/ietele/e88-c.7.1375

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  • 誘電体内に素子を装荷した軸対称型ファブリペロー多素子発振器

    佐薙稔, 沖哲也, 中西信人, 藤森和博, 野木茂次

    電子情報通信学会論文誌   2005年

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  • 第2高調波を放射する能動フェーズドアレーアンテナ

    佐薙稔, 矢野健治, 藤森和博, 野木茂次

    電子情報通信学会論文誌   2004年

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  • Broadband Conical-Radial Line Power Divider Incorporating Coaxial Branch Probes

    M.Sanagi, T.Hayashi, K.Fujimori, S.Nogi

    Asia-Pacific Microwave Conference Proc.   2003年

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  • Propagation characteristics in tunnels including base station antenna

    K Fujimori, H Arai

    ELECTRONICS AND COMMUNICATIONS IN JAPAN PART I-COMMUNICATIONS   84 ( 4 )   1 - 10   2001年

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    記述言語:英語   出版者・発行元:SCRIPTA TECHNICA-JOHN WILEY & SONS  

    The measured results and the results of analysis by the ray tracing method in a real tunnel are compared. The propagation characteristics considering the radiation pattern of an antenna placed inside the tunnel are estimated. By comparison of the measured and analyzed results, the effectiveness and validity of the ray tracing method are shown. The propagation loss and fading in the tunnel are discussed. Further, the propagation characteristic is estimated by considering the radiation pattern of the base station antenna for the tunnel booster system. The analysis demonstrates that the dual radiation pattern is effective for the base station antenna. The variation of the covered area when the radiation pattern is varied is studied. (C) 2000 Scripta Technica.

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  • Polarization Diversity Antenna System for Wireless Data Link

    H.Arai, K.Fujimori

    IEE Millennium Conference on Antennas and Propagation Proc.   2000年

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  • Bent Patch Antenna for Polarization Diversity Antenna

    K.Fujimori, S.Nogi, H.Arai

    Asia-Pacific Microwave Conference Proc.   2000年

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  • 基地局アンテナを考慮したトンネル内伝搬特性

    藤森和博, 新井宏之

    電子情報通信学会論文誌B   1999年

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受賞

  • 岡山工学振興会科学技術賞

    2011年  

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    受賞国:日本国

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