研究者業績
基本情報
- 所属
- 国立研究開発法人宇宙航空研究開発機構 宇宙科学研究所 宇宙機応用工学研究系 特任教授
- 学位
- 学術博士(University of California, Los Angels（アメリカ合衆国）)
- J-GLOBAL ID
- 200901092149206485
- researchmap会員ID
- 1000168389
- 外部リンク
研究キーワード
12研究分野
6経歴
12-
2019年4月 - 現在
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2008年10月
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2006年6月
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2004年10月
学歴
5-
- 1981年3月
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- 1979年3月
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- 1979年
委員歴
5受賞
6-
2012年10月
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2005年3月
論文
98-
Asia-Pacific Microwave Conference Proceedings, APMC 542-545 2023年This paper presents the fabrication of an Active Integrated Phased Array Antennas (AIPAA) sensor system prototype utilizing Information, Communication & Energy transfer (ICEt) technology. Through the high-density integration of hardware components and software algorithms, this system enables adaptive adjustments in diverse scenarios, leading to optimal system performance. The proposed prototype demonstrates the capability to fulfill sensing, communication, and energy transfer tasks in various environments, including spacecraft exploration and river disaster warning systems. This research represents a significant step towards the development of advanced wireless sensor networks with ICEt technology for multifunctional applications.
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SN Applied Sciences 2(12) 2020年12月1日We report on the irreversible and reversible resistance changes for γ-ray irradiation in amorphous GeTe thin films with Ag electrodes. The γ-ray irradiation at a dose of 1 kGy irreversibly decreased the DC resistance by two orders of magnitude. The irreversible resistance change was caused by the formation of a conductive region that consisted of Ag-Te compounds. In-situ real-time DC resistance and AC impedance measurements revealed reversible variations in several electrode structures with DC resistances ranging widely from about 10 kΩ to about 5 MΩ. The DC resistance decreased by 2–5% with a time constant of about 3–7 min following the γ-ray irradiation with a dose rate of 0.5–2 kGy/h, and recovered on interruption. The AC impedance measurement was analyzed with a simple equivalent circuit consisting of a parallel RC circuit of the Ag-diffused GeTe matrix, connected serially to the interface resistance. The interface resistance and the capacitance of the matrix exhibited a fast reversible variation, which is explained by trapping and detrapping of carriers in the charged defects formed by the Ag re-diffusion. The resistance of the matrix showed a slow reversible variation with a time constant of 7 min, similar to the DC resistance. The slow reversible variation is attributed to the growth and dissolution of the conductive region caused by the Ag re-diffusion.
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IEEE Microwave and Wireless Components Letters 30(10) 997-1000 2020年10月© 2020 IEEE. In this letter, a frequency-tunable rectifier in the $C$-band designed by a hybrid semiconductor integrated circuit (HySIC) concept is proposed. A GaAs monolithic microwave integrated circuit (MMIC) and a Si radio frequency integrated circuit (RFIC) were utilized as the HySIC configuration in the rectifier design. For the purpose of initial confirmation of this design validity, the GaAs and Si chips were fabricated and packaged onto the copper tungsten plate with gold plating. As measured results, frequency-tunable range from 3.82 to 4.55 GHz was measured. Maximum radio frequency (RF)-direct current (dc) conversion efficiency and output dc power in the measured power range from-10.0 to 17.8 dBm were 28.7% and 17.3 mW, respectively.
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IEEE MTT-S International Microwave Symposium Digest 2020-August 1180-1183 2020年8月© 2020 IEEE. The 24 GHz communication system was demonstrated with wireless multi-sensors by wirelessly powering at 5.8 GHz. The wireless sensors for health monitoring in a space vehicle work as the sensors of temperature, humidity, acceleration, illuminance, battery voltage and sound in this study. Under output power of 30W from a GaN transmitter, a GaAs rectifier of energy harvester was operated with more than 80% RF-DC conversion efficiency.
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2020 33rd General Assembly and Scientific Symposium of the International Union of Radio Science, URSI GASS 2020 2020年8月© 2020 URSI. This paper analyzes and optimizes the structure of gallium nitride (GaN) planar Schottky barrier diode (SBD) to maximize the rectifier RF-DC conversion efficiency (PCE) and the operating dynamic range. The analysis indicates a small series resistance and a small zero-bias junction capacitance were needed to improve the wide dynamic range performance of the rectifier circuit. The prototype single-shunt rectifiers using the proposed GaN SBDs for evaluation achieves a conversion efficiency of more than 80% at an input power of 40dBm at 5. 8GHz. The high efficiency design rectifier achieves 87% peak PCE with 23dB dynamic range. The wide dynamic range design rectifier achieves 78% peak PCE with 32dB dynamic range.
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2019 IEEE Wireless Power Transfer Conference, WPTC 2019 595-598 2019年6月© 2019 IEEE. This paper demonstrates fundamental evaluation results of a C-band rectifier using gallium nitride (GaN) high electron mobility transistor (HEMT). To achieve rectification at high power range, the GaN HEMT is utilized. TGF2023-2-05 of Qorvo is used for the HEMT. A rectifier circuit is designed on a RO4350B substrate. Only fundamental wave matching is considered. The designed rectifier is fabricated and measured. Maximum rectification efficiency of 44.8 % at 5.78 GHz while the load resistance is 20Omega is obtained from the measurement. Maximum output DC power is 9661 mW when RF input power is 44.2dBm.
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Acta Astronautica 160 147-154 2019年4月
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IEEE TRANSACTIONS ON AEROSPACE AND ELECTRONIC SYSTEMS 55(2) 930-938 2019年4月An X-band, Gallium nitride (GaN)-based solid-state power amplifier (SSPA) was demonstrated formore than one year in deep space for the first time. The SSPA consisted of three-stage amplifiers and commercial off-the-shelf (COTS) GaN high-electron-mobility transistors (HEMTs) were used in both the second-and the final-stage amplifiers. During its one year of continuous operation, the GaN SSPA improved equivalent isotopically radiated power with low power consumption such as an average output power of 41.7 dBm (14.8W), average power consumption of 43.5 W, and average efficiency of 33.7%. In addition, the deterioration rate of output power calculated from the inclination of the linear approximation line was no more than -0.08 dB per year. These results stand comparison with the results of high-temperature, long-term continuous operation test or a total ionizing dose test conducted on the ground. This paper illustrates the space applicability and reliability of the SSPA using a COTS GaN HEMT.
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Proc. 2019 Radio & Wireless Symposium WE2A-1 2019年1月 査読有り
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IEICE Communications Express 8(4) 1-6 2019年1月
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IEEE Transactions on Aerospace and Electronic Systems 55(2) 930-938 2019年
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The 30th Symposium on Phase Change Oriented Science PCOS 2018 3 2018年12月 査読有り
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Proc. 2018 Asia Pacific Microwave Conf. 46-48 2018年11月 査読有り
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Asian Wireless Power Transfer Workshop 2018年11月 査読有り
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IEEE MTT-S Int. Microw. Symp. Dig. Th2B-3 1265-1268 2018年6月 査読有り
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in Proc. Int. Wireless Symp 2018年5月 査読有り
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Journal of Astronomical Telescopes, Instruments, and Systems 4(2) 021402 2018年4月 査読有り© The Authors. The Hitomi (ASTRO-H) mission is the sixth Japanese x-ray astronomy satellite developed by a large international collaboration, including Japan, USA, Canada, and Europe. The mission aimed to provide the highest energy resolution ever achieved at E > 2 keV, using a microcalorimeter instrument, and to cover a wide energy range spanning four decades in energy from soft x-rays to gamma rays. After a successful launch on February 17, 2016, the spacecraft lost its function on March 26, 2016, but the commissioning phase for about a month provided valuable information on the onboard instruments and the spacecraft system, including astrophysical results obtained from first light observations. The paper describes the Hitomi (ASTRO-H) mission, its capabilities, the initial operation, and the instruments/spacecraft performances confirmed during the commissioning operations for about a month.
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2018 IEEE Radio and Wireless Symposium(RWS) 91-93 2018年
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IEEJ Transactions on Industry Applications 138(7) 615-622 2018年© 2018 The Institute of Electrical Engineers of Japan. In this paper, we demonstrate the experimental evaluation of system feasibility of a wireless sensor network system powered by a hybrid energy harvester inside a reusable vehicle test (RVT). The hybrid energy harvester consists of a solar cell and a microwave rectifier as a passive and an active powering method, respectively. Basic characteristic measurement of the hybrid energy harvester under line-of-sight conditions and multi-sensor operation under non-line-of-sight conditions were carried out using the real RVT which is covered by an aeroshell.
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European Microwave Week 2017: "A Prime Year for a Prime Event", EuMW 2017 - Conference Proceedings; 47th European Microwave Conference, EuMC 2017 2017- 1155-1158 2017年12月19日 査読有りThis paper proposes and demonstrates a novel wide dynamic range rectifier. The proposed rectifier consists of two rectifying circuits in parallel, an asymmetrical output impedance power divider for RF input signal, and a DC combiner. The asymmetric power divider sequentially distributes the RF signal to the rectifier for high input power from the rectifier for low input power without switch devices, according as the input signal power level increases. The fabricated 2.45 GHz rectifier verified the proposed technique and expanded the operating input power range. The fabricated rectifier demonstrated more than 25dB dynamic range with an efficiency of higher than 30%. The maximum efficiency of the rectifier achieved 47.5% at 15dBm input power.
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2017 12th European Microwave Integrated Circuits Conference, EuMIC 2017 2017- 415-418 2017年12月19日 査読有りThis paper proposes and demonstrates a novel wide dynamic range rectifier. The proposed rectifier consists of two rectifying circuits in parallel, an asymmetrical output impedance power divider for RF input signal, and a DC combiner. The asymmetric power divider sequentially distributes the RF signal to the rectifier for high input power from the rectifier for low input power without switch devices, according as the input signal power level increases. The fabricated 2.45 GHz rectifier verified the proposed technique and expanded the operating input power range. The fabricated rectifier demonstrated more than 25dB dynamic range with an efficiency of higher than 30%. The maximum efficiency of the rectifier achieved 47.5% at 15dBm input power.
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IEEE MTT-S International Microwave Symposium Digest 1042-1045 2017年10月4日 査読有り© 2017 IEEE. This paper proposes and demonstrates a concurrent 2.45GHz/5.8GHz rectifier. The proposed concurrent dual-band rectifier drastically improves its RF-DC conversion efficiency with a harmonic signal control technique. The proposed rectifier employs two key designs. A microstrip spurline notch filter in the output section realizes high RF-DC conversion efficiencies at the dual bands. The quarter-wave length open stub of the 8.25 GHz connected at diode cathode effectively terminates the harmonic signal generated by mixing the input signals. The proposed configuration provides the high RF-DC conversion efficiency even when two-tone signals input the rectifier. The fabricated the dual-band rectifier achieves the RF-DC conversion efficiencies of 64.8 %, 62.2 %, and 67.9 % at 2.45 GHz, 5.8 GHz, and their two-tone input signals, respectively.
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2017 IEEE Int. Symp. on Radio-Frequency Integrated Technology (RFIT) Dig 147-149 2017年9月 査読有り
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2017 Thailand-Japan MicroWave FR3-04 2017年6月 査読有り
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ISTS, ISSFD & NSAT 2017 2017年6月 査読有り
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Feasibility evaluation of wireless powering sensor network system for a frequent reusable spacecraftProc. Vietnam-Japan Microwave Conf. 2017年6月 査読有り
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2017 Thailand-Japan MicroWave TH1-17 2017年6月 査読有り
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2017 Thailand-Japan MicroWave FR3-04 2017年6月 査読有り
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2017 IEEE Int. Microwave Symp. Proc. 1042-1045 2017年6月 査読有り
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IEEE MTT-S Trans. 2017年
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2017 IEEE WIRELESS POWER TRANSFER CONFERENCE (WPTC 2017) 1-3 2017年 査読有りThis paper demonstrates fundamental evaluation results of a C-band rectifier using Si substrate for HySIC application. Usage of the Si substrate is attractive for future integration with other mixed signal circuit. Because of large loss tangent of the Si substrate, applicability as a circuit substrate to the C-band rectifier is discussed. Two types of the rectifier, conventional printed circuit board and the Si substrate, are designed and fabricated. Maximum rectification efficiency of 10.4% at 5.39 GHz while the load resistance is 20 Omega is obtained from the measurement.
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2017 IEEE WIRELESS POWER TRANSFER CONFERENCE (WPTC 2017) 1-3 2017年 査読有りThis paper reports on a rectifier with 100 mW class dc output at 5.8 GHz using a gallium nitride (GaN) shottly barrier diode and silicon (Si) matching circuit. The originality of the study lies in its adaptation of the hybrid semiconductor integrated circuit (HySIC) technology that utilizes different types of semiconductors. We have completed the basic steps for developing a rectifier based on the HySIC technology. A nonlinear measurement system of GaN diodes with a jig was constructed and an equivalent circuit model of the diode was established. Based on the diode model, a Si matching circuit was designed. The size of the HySIC rectifier was 3.9 mmx9.5 mm. The RF-dc conversion efficiency of the HySIC rectifier was 10.3% at 5.8 GHz.
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2017 IEEE WIRELESS POWER TRANSFER CONFERENCE (WPTC 2017) 1-4 2017年 査読有りThis paper reports on a rectifier with 100 mW class dc output at 5.8 GHz using a gallium nitride (GaN) shottly barrier diode and silicon (Si) matching circuit. The originality of the study lies in its adaptation of the hybrid semiconductor integrated circuit (HySIC) technology that utilizes different types of semiconductors. We have completed the basic steps for developing a rectifier based on the HySIC technology. A nonlinear measurement system of GaN diodes with a jig was constructed and an equivalent circuit model of the diode was established. Based on the diode model, a Si matching circuit was designed. The size of the HySIC rectifier was 3.9 mmx9.5 mm. The RF-dc conversion efficiency of the HySIC rectifier was 10.3% at 5.8 GHz.
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IEICE TRANSACTIONS ON ELECTRONICS E99C(10) 1085-1093 2016年10月 査読有りThe concept, state of the art, and future development directions of hybrid semiconductor integrated circuits (HySICs), which combine RF-CMOS ICs with compound semiconductor monolithic microwave integrated circuits (MMICs) are described in this paper, taking up recent wireless technologies as example applications. It is shown that ICs with superior function can be designed by mixing the optimal characteristics from the different semiconductors. To realize new semiconductor ICs, several component technologies for RF-HySIC are introduced in terms of chip/MMIC design, measurement, and breadboard model fabrication. A prototype RF-HySIC is described for the combination of a GaN Schottky barrier diode with a Si RF-IC matching network developed at 5.8 GHz. A GaN diode structure, measurement and characterization of nonlinear devices, a GaN amplifier, and a GaAs MMIC are introduced as component technologies. In addition, the design for using an RF-CMOS matching network circuit with a size of 1.2 mm x 2.3 mm and room-temperature chip/wafer direct bonding under high-pressure conditions are explained. For advanced and autonomous ICs, HySIC and chip/MMIC topologies combined with a processor are proposed for application of HySIC to wireless sensor systems.
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IEICE TRANS. ELECTRON. E99C(10) 1140-1146 2016年10月 査読有り
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2016 Thailand-Japan Microwave Workshop 2016年6月
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IEEE TRANSACTIONS ON AEROSPACE AND ELECTRONIC SYSTEMS 52(3) 1340-1351 2016年6月 査読有り
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Impact of Symbol Rate and Roll-off Factor on Rectifier RF-DC Conversion Efficiency for WiCoPT System2016 46TH EUROPEAN MICROWAVE CONFERENCE (EUMC) 934-937 2016年 査読有りWireless Communication and Power Transmission (WiCoPT) is a technology that enables to transfer data and power simultaneously. This paper analyzes and clarifies the impact of input modulated signals on the RF-DC power conversion behavior of the rectifier. The RF-DC power conversion efficiency (PCE) was characterized by input power, symbol rate, and roll -off factor of the modulated input signal. On the low symbol rate signal, the impact of the peak to average power ratio (PAPR) value on the PCE is low, while the impact of PAPR value on the PCE is high on the high symbol rate signal. In addition, the optimal combination of the symbol rate and the roll off factor greatly improves the RF-DC PCE. Finally, the paper proposes the channel bandwidth as an index of the PCE.
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2016 IEEE INTERNATIONAL SYMPOSIUM ON RADIO-FREQUENCY INTEGRATION TECHNOLOGY (RFIT) 2016年 査読有りThis paper proposes and demonstrates a novel dual-band rectifier at 2.45 GHz and 5.8 GHz. The proposed rectifier employs a microstrip spurline notch filter to realize dual-band high RF-DC conversion efficiency. The control of reflected signals from the output filter to maximize the voltage swing at the diode, and use of the spurline notch filter provide high-level conversion efficiencies at both operating frequency bands. The fabricated proposed dual-band rectifier achieves the RF-DC conversion efficiencies of 55.9 % and 55.4 % at 2.15 GHz and 5.84 GHz, respectively. These results are top-level performances of the dual-band rectifiers.
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2016 IEEE MTT-S INTERNATIONAL MICROWAVE SYMPOSIUM (IMS) THIF2-29 2016年 査読有りThis research reports a 5.8-GHz band GaN (Gallium Nitride) diode rectifier for high power microwave power transmission (MPT) systems. Designed rectifier is fabricated and measured. The fabricated rectifier has Cu heat sink because of the high power operation. The GaN diode is directly mounted on the heat sink. Also, fabricated substrate is screwed to the heat sink. Measured RF-DC conversion efficiency and output DC power at 5.9GHz are 32.6% and 3042mW, respectively. This report makes a first step for future miniaturization by the hybrid semiconductor integrated circuit (HySIC) technology which utilizes different type semiconductor devices.
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2016 IEEE WIRELESS POWER TRANSFER CONFERENCE (WPTC) Session V-4 2016年 査読有りThis paper investigated coexistence possibility of high efficiency Wireless Power Transfer (WPT) system and high-speed communication system in Short-range Wireless Communication and Power Transfer (WiCoPT) system. To realize both high power transfer efficiency and high data rate, this paper proposes the WiCoPT system, which is supported by the Short-Range Multiple Input and Multiple Output (SR-MIMO) transfer technique. Relationship between the antenna element spacing and the transmission performance was analyzed to clarify the maximum performances of the power transfer efficiency and the data rate. The paper analyzed and demonstrated a 4x4 MIMO WiCoPT system. The numerical analysis indicates that the antenna element spacing to maximize the power transfer efficiency is different from that to realize the highest channel capacity. In addition, the analysis clarifies there are two suitable antenna element spacing for high power transfer operation. Therefore, our proposing system chose the antenna element spacing to realize the second peak for the high-level power transfer efficiency simultaneously. The 4x4 MIMO WiCoPT system achieved a channel capacity of 45 bit/s/Hz and a power transfer efficiency of 64.8 %.
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2016 CONFERENCE ON PRECISION ELECTROMAGNETIC MEASUREMENTS (CPEM 2016) 2016年 査読有りThis paper summarizes the uncertainty estimation for gallium nitride shottky diode based on vector network analyzer measurements at 5.8 GHz. The results were traceable to the metrology standard of S-parameter at NMIJ. Considering the uncertainty of the measurements, bias voltage must be applied over 2 V in measuring bias voltage dependence of reflection coefficient. The measurement uncertainty was propagated from reflection coefficient to impedance. As a result, the expanded uncertainty of real and imaginary part of impedance were 0.56 Omega and 0.57 Omega at 5.8 GHz, respectively.
MISC
497-
電子情報通信学会技術研究報告 = IEICE technical report : 信学技報 119(204) 37-42 2019年9月19日
書籍等出版物
5講演・口頭発表等
7-
KMITL_Kagoshima U joint seminar - Space Electronics Technologies and Applications 2016年10月22日
所属学協会
6Works(作品等)
1共同研究・競争的資金等の研究課題
8-
日本学術振興会 科学研究費助成事業 2011年4月 - 2015年3月
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日本学術振興会 科学研究費助成事業 2009年 - 2012年
