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FOREWORD
2021
IEICE transactions on electronics
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Takana Kaho (Shonan Institute of Technology), Guest Editor-in-Chief Takana Kaho (Senior Member) received the B.S. and M.S. degrees in physics from Tokyo Metropolitan University, Japan, in 1994 and 1996 ...
doi:10.1587/transele.2021mmf0001
fatcat:assqtdvirnaclitw2jctbjlhra
NTT研究所における子供科学教室
2014
IEICE Communications Society Magazine
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加保貴奈 Takana Kaho 日本電信電話 (株) NTT 未来ねっと研究所 水野秀之 Hideyuki Mizuno 日本電信電話 (株) NTT メディアインテリジェンス研究所 1 はじめに
2013 年 7 月 20 日 (土) に NTT 横須賀研究開発センタ
一般公開と電子情報通信学会東京支部と共同で子供向け
の科学教室を行った．当教室は 2010 年から地域の小中
学生向 ...
doi:10.1587/bplus.7.303
fatcat:3gwcii3ml5cqxoujtqtk2pe3ry
Improved gain 60 GHz CMOS antenna with N-well grid
2016
IEICE Electronics Express
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This paper presents a novel technique to enhance Antenna-on-Chip gain by introducing a high resistivity layer below it. Instead of using the costly ion implantation method to increase resistivity, the N-well that is available in the standard CMOS process is used. A distributed grid structure of N-well on P-type substrate is designed such that the P and N semiconductors types are fully depleted forming a layer with high resistivity. By an electromagnetic simulation, the using depletion layers
doi:10.1587/elex.13.20151115
fatcat:bqn7leplorgxhhxb4feen3jir4
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... ance the antenna gain and radiation efficiency without increasing the occupied area. The simulated and measured |S11| are in fair agreement. The measured gain is −1.5 dBi at 66 GHz.
A 12 to 24 GHz high efficiency fully integrated 0.18 µm CMOS power amplifier
2016
IEICE Electronics Express
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This letter presents a high efficiency, and small group delay variations 12-24 GHz fully-integrated CMOS power amplifier (PA) for quasi-millimeter wave applications. Maximizing the power added efficiency (PAE), and minimizing the group delay variations in a wideband frequency range are achieved by optimizing the on-chip input, output, and inter-stage matching circuits. In addition, stagger tuning is employed for realizing excellent gain flatness. A two-stage CMOS PA using the proposed
doi:10.1587/elex.13.20160551
fatcat:uysd4mhf7jcfzdsjrw4eu5yoce
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... y is designed and fabricated in 0.18 µm CMOS technology and tested. A measured power gain (|S 21 |) of 10.5 ± 0.7 dB and a measured small group delay variation of ±20 ps over the frequency range of interest are achieved. The PA shows a maximum measured PAE to be 26 % with DC power consumption of 50 mW.
Nonlinear Modeling and Analysis on Concurrent Amplification of Dual-Band Gaussian Signals
2013
IEICE transactions on electronics
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In the recently developed Flexible Wireless System (FWS), the same platform needs to deal with different wireless systems. This increases nonlinear distortion in its wideband power amplifier (PA) because the PA needs to concurrently amplify multi-band signals. By taking higher harmonics as well as inter-and cross-modulation distortion into consideration, we have developed a method to analytically evaluate the adjacent channel leakage power ratio (ACPR) and error vector magnitude (EVM) on the
doi:10.1587/transele.e96.c.1254
fatcat:bj66lhhf35e7pjytyuncpqnqke
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... is of the PA's nonlinear characteristics. We devise a novel method for modeling the PA amplifying dual-band signals. The method makes it possible to model it merely by performing a one-tone test, making use of the Volterra series expansion and the general Wiener model. We then use the Mehler formula to derive the closed-form expressions of the PA's output power spectral density (PSD), ACPR, and EVM. The derivations are based on the assumption that the transmitted signals are complex Gaussian distributed in orthogonal frequency division multiplexing (OFDM) transmission systems. We validate the method by comparing measurement and simulation results and confirm it can appropriately predict the ACPR and EVM performance of the nonlinear PA output with OFDM inputs. In short, the method enables correct modeling of a wideband PA that amplifies dualband signals merely by conducting a one-tone test.
Reduction of Heat Generation from Onboard SSPA by Using Heat Suppression Signal
発熱抑制信号による衛星搭載用中継器の発熱低減評価
2004
JOURNAL OF THE JAPAN SOCIETY FOR AERONAUTICAL AND SPACE SCIENCES
発熱抑制信号による衛星搭載用中継器の発熱低減評価
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Satellite communication systems have entered into the mobile multimedia communication era. To support small earth terminals, the satellites must have high levels of effective isotropic radiated power. Onboard high-power amplifiers are not only needed to generate high RF output power, but also to generate as less heat as possible. To address this issue, we present a new technique reducing an amount of heat generated in high power amplifiers on a satellite. The technique makes use of heat
doi:10.2322/jjsass.52.507
fatcat:iwpmi2cfpbbcdl7iro3tzqsfkm
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... ion signals so as to maintain the amplifier's power efficiency. The dissipation heat has been conventionally evaluated by consumption power of loaded FETs. However, the validity of this method has not yet been clarified on an experimental basis. Therefore, the dissipation heat from SSPAs was evaluated by other measurement technique, that is, we measured temperatures of SSPA and of air cooling. Furthermore, an effect of heat suppression was demonstrated.
FOREWORD
2014
IEICE transactions on electronics
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.), Kazufumi Igarashi (Japan Radio), Takana Kaho (NTT), Masayuki Kimishima (ADVANTEST), Zhewang Ma (Saitama Univ.), Kenjiro Nishikawa (Kagoshima Univ.), Kensuke Okubo (Okayama Pref. ...
doi:10.1587/transele.e97.c.922
fatcat:rtin27afwbcxfafpyfegwqercq
FOREWORD
2018
IEICE transactions on electronics
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.), Ryo Ishikawa (The Univ. of Electro-Communications), Takana Kaho (NTT), Kazuhiro Iyomasa (Mitsubishi Electric), Zhewang Ma (Saitama Univ.), Masaya Tamura (Toyohashi Univ. of Tech.), Hiroyuki Kayano ...
doi:10.1587/transele.e101.c.718
fatcat:g5eo7cpqubabtcopjvtz64qwz4
Acknowledgments to Referees
2019
TRANSACTIONS OF THE JAPAN SOCIETY FOR AERONAUTICAL AND SPACE SCIENCES AEROSPACE TECHNOLOGY JAPAN
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TAKANA
Atsushi TAKANO
Yoshihisa TAKAYAMA
Shin-ichi TAKEDA
Yoshiaki TAKEUCHI
Mitsuaki TANABE
Hiroaki TANAKA
Hiroumi TANI
Gordan Ray THIEDE
Nobuyuki TSUBOI
Takeshi TSUCHIYA
Taro TSUKAMOTO ...
Toshiyuki SUZUKI
Yoichi SUZUKI
Halil Ersin SÖKEN
Hirokazu TAHARA
Atsushi TAKADA
Hideyuki TAKAHASHI
Kenichi TAKAHASHI
Masaya TAKAHASHI
Masayuki TAKAHASHI
Shun TAKAHASHI
Yusuke TAKAHASHI
Kaho ...
doi:10.2322/tastj.17.611
fatcat:srtxwl7j6ve55gsqjyamluujgq
Tietoa vahvistamassa ja saatavuutta parantamassa – NordILL 2021 -konferenssin satoa
2022
Signum
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Elina Kähö ja Juha Leppämäki esittelivät Helsingin yliopiston kirjaston Alma-kehittämishanketta. ...
Sopimuksissa on myös ehtona välitön avoin julkaisu ilman, että aineistoa ensin pidetään maksumuurin takana. ...
doi:10.25033/sig.113615
fatcat:4qxake5o55f65eawcunujfxbs4