Takashi OHIRA


Power Dependent Impedance Measurement Exploiting an Oscilloscope and Möbius Transformation
Sonshu SAKIHARA Masaru TAKANA Naoki SAKAI Takashi OHIRA 
Publication:   
Publication Date: 2017/10/01
Vol. E100-C  No. 10  pp. 918-923
Type of Manuscript:  Special Section PAPER (Special Section on Microwave and Millimeter-Wave Technology)
Category: 
Keyword: 
nonlinear impedance measurementMöbius transformationoscilloscopemeasurabilityRF rectifier
 Summary | Full Text:PDF(3.3MB) | (Errata[Uploaded on November 1,2017])

Internal Power Loss Formulas of Lumped-Element Matching Circuits for High-Efficiency Wireless Power Transfer
Kyohei YAMADA Naoki SAKAI Takashi OHIRA 
Publication:   IEICE TRANSACTIONS on Electronics
Publication Date: 2016/10/01
Vol. E99-C  No. 10  pp. 1182-1189
Type of Manuscript:  Special Section PAPER (Special Section on Microwave and Millimeter-Wave Technology)
Category: 
Keyword: 
wireless power transferimpedance matchingQ factorinternal lossformulation
 Summary | Full Text:PDF(541.5KB)

Active Q Factor Analysis for Non-uniform Microstrip Stub Colpitts FET Oscillators
Tuya WUREN Takashi OHIRA 
Publication:   IEICE TRANSACTIONS on Fundamentals of Electronics, Communications and Computer Sciences
Publication Date: 2011/02/01
Vol. E94-A  No. 2  pp. 583-591
Type of Manuscript:  Special Section PAPER (Special Section on Analog Circuit Techniques and Related Topics)
Category: 
Keyword: 
oscillatorQ factornon-uniform microtrip lineFETtransconductancemicrowave
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Interference Canceller Based on Cycle-and-Add Property for Single User Detection in DS-CDMA
Ranga HETTIARACHCHI Mitsuo YOKOYAMA Hideyuki UEHARA Takashi OHIRA 
Publication:   IEICE TRANSACTIONS on Fundamentals of Electronics, Communications and Computer Sciences
Publication Date: 2009/01/01
Vol. E92-A  No. 1  pp. 298-306
Type of Manuscript:  PAPER
Category: Spread Spectrum Technologies and Applications
Keyword: 
DS-CDMAsingle user detectioninterference cancellationmultiple access interference (MAI)PN sequencescycle-and-add propertynear-far problem (NFP)
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Pseudolinear Circuit Theory for Sinusoidal Oscillator Performance Maximization
Takashi OHIRA Tuya WUREN 
Publication:   IEICE TRANSACTIONS on Electronics
Publication Date: 2008/11/01
Vol. E91-C  No. 11  pp. 1726-1737
Type of Manuscript:  INVITED PAPER (Special Section on Microwave and Millimeter-wave Technologies)
Category: 
Keyword: 
oscillatorNINO modelimmittance-domain Barkhausen conditionequilibriumactive Q factorcircuit optimization criteria
 Summary | Full Text:PDF(1.4MB)

FOREWORD
Takashi OHIRA 
Publication:   IEICE TRANSACTIONS on Electronics
Publication Date: 2006/12/01
Vol. E89-C  No. 12  pp. 1796-1797
Type of Manuscript:  FOREWORD
Category: 
Keyword: 
 Summary | Full Text:PDF(68.5KB)

Spatial Fading Simulator Using a Cavity-Excited Circular Array (CECA) for Performance Evaluation of Antenna Arrays
Chulgyun PARK Jun-ichi TAKADA Kei SAKAGUCHI Takashi OHIRA 
Publication:   IEICE TRANSACTIONS on Communications
Publication Date: 2006/03/01
Vol. E89-B  No. 3  pp. 906-913
Type of Manuscript:  PAPER
Category: Antennas and Propagation
Keyword: 
spatial fading simulatorcavityCECAantenna array performance evaluation
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A Compact Espar Antenna with Planar Parasitic Elements on a Dielectric Cylinder
Qing HAN Brett HANNA Takashi OHIRA 
Publication:   IEICE TRANSACTIONS on Communications
Publication Date: 2005/06/01
Vol. E88-B  No. 6  pp. 2284-2290
Type of Manuscript:  Special Section PAPER (Special Section on 2004 International Symposium on Antennas and Propagation)
Category: 
Keyword: 
Espardielectricdirection findergenetic algorithmminiaturization
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Perturbation Analysis and Experimental Verification of Intermodulation and Harmonic Distortion for an Anti-Series Varactor Pair
Qing HAN Keizo INAGAKI Takashi OHIRA 
Publication:   IEICE TRANSACTIONS on Electronics
Publication Date: 2005/01/01
Vol. E88-C  No. 1  pp. 89-97
Type of Manuscript:  Special Section PAPER (Special Section on Recent Trends of Microwave and Millimeter-Wave Passive Circuit Components and Technologies for Improvement of Characteristics)
Category: 
Keyword: 
anti-series-varactor-pairabrupt p-n junctionnonlinear distortionperturbation method
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Numerical Analysis of Nonlinear Distortion Generated from a Single Varactor and an Anti-Series Varactor Pair
Masami AKAIKE Takashi OHIRA Keizo INAGAKI Qing HAN 
Publication:   IEICE TRANSACTIONS on Electronics
Publication Date: 2002/12/01
Vol. E85-C  No. 12  pp. 1990-1999
Type of Manuscript:  Special Section PAPER (Special Issue on Low-Distortion,High-Power,High-Efficiency Active Device and Circuit Technology)
Category: 
Keyword: 
nonlinear distortionvaractoranti-seriesharmonic distortionnonlinear analysis
 Summary | Full Text:PDF(1.1MB)

Harmonic Distortion Suppression Technique for Varactor-Loaded Parasitic Radiator Antennas
Qing HAN Keizo INAGAKI Kyouichi IIGUSA Robert SCHLUB Takashi OHIRA Masami AKAIKE 
Publication:   IEICE TRANSACTIONS on Electronics
Publication Date: 2002/12/01
Vol. E85-C  No. 12  pp. 2015-2021
Type of Manuscript:  Special Section PAPER (Special Issue on Low-Distortion,High-Power,High-Efficiency Active Device and Circuit Technology)
Category: 
Keyword: 
ESPAR antennavaractor diodenonlinearharmonic distortionreactive near-field measurement
 Summary | Full Text:PDF(665.6KB)

Reactive-Field Anechoic Box for ESPAR Antenna Measurement
Qing HAN Keizo INAGAKI Kyouichi IIGUSA Robert SCHLUB Takashi OHIRA 
Publication:   IEICE TRANSACTIONS on Electronics
Publication Date: 2002/07/01
Vol. E85-C  No. 7  pp. 1451-1459
Type of Manuscript:  PAPER
Category: Electromagnetic Theory
Keyword: 
reactive-field anechoic boxbackscattering characteristicsradio wave absorberESPAR antennareactive near field
 Summary | Full Text:PDF(398KB)

Adaptive Control Algorithm of ESPAR Antenna Based on Stochastic Approximation Theory
Blagovest SHISHKOV Jun CHENG Takashi OHIRA 
Publication:   IEICE TRANSACTIONS on Communications
Publication Date: 2002/04/01
Vol. E85-B  No. 4  pp. 802-811
Type of Manuscript:  PAPER
Category: Antenna and Propagation
Keyword: 
adaptive beamformingESPAR antennainterference reductionrate of convergencestochastic approximation
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Adaptive Beamforming of ESPAR Antenna--Unconventional Approach
Blagovest SHISHKOV Jun CHENG Takashi OHIRA 
Publication:   IEICE TRANSACTIONS on Electronics
Publication Date: 2002/03/01
Vol. E85-C  No. 3  pp. 452-457
Type of Manuscript:  Special Section PAPER (Special Issue on Signals, Systems and Electronics Technology)
Category: Digital Transmission
Keyword: 
ESPAR antennaadaptive beamformingstochastic approximationinterference reductionconvergencegradient noiseHessian
 Summary | Full Text:PDF(500.9KB)

Fourier Optical Processing Beamforming Network Using Optical Waveguide Arrays and Lens for Transmission and Reception
Tomohiro AKIYAMA Keizo INAGAKI Yoshihiko MIZUGUCHI Takashi OHIRA 
Publication:   IEICE TRANSACTIONS on Communications
Publication Date: 2001/09/01
Vol. E84-B  No. 9  pp. 2413-2420
Type of Manuscript:  Special Section PAPER (Special Issue on Innovation in Antennas and Propagation for Expanding Radio Systems)
Category: Millimeter-Wave Antennas
Keyword: 
optically controlled array antennaoptical signal processingphased array antennaoptical waveguidebeamforming network
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An Optical Waveguide with High Birefringence and Birefringence Dispersion for Optical Beamforming Network in Multibeam Array Antenna
Weiwei HU Keizo INAGAKI Takashi OHIRA 
Publication:   IEICE TRANSACTIONS on Communications
Publication Date: 2001/07/01
Vol. E84-B  No. 7  pp. 1801-1807
Type of Manuscript:  Special Section PAPER (Special Issue on Adaptive Array Antenna Techniques for Advanced Wireless Communications)
Category: Beamformer Techniques
Keyword: 
Ti:LiNbO3 optical waveguidebirefringenceoptical beamforming networkmultibeam phase array antenna
 Summary | Full Text:PDF(1.2MB)

Adaptive Beamforming of ESPAR Antenna Based on Steepest Gradient Algorithm
Jun CHENG Yukihiro KAMIYA Takashi OHIRA 
Publication:   IEICE TRANSACTIONS on Communications
Publication Date: 2001/07/01
Vol. E84-B  No. 7  pp. 1790-1800
Type of Manuscript:  Special Section PAPER (Special Issue on Adaptive Array Antenna Techniques for Advanced Wireless Communications)
Category: Beamformer Techniques
Keyword: 
gradient algorithmadaptive beamformingmobile user terminalinterference reductionlow complexity
 Summary | Full Text:PDF(966KB)

S-Band Mobile Satellite Communications and Multimedia Broadcasting Onboard Equipment for ETS-VIII
Yoichi KAWAKAMI Shigetoshi YOSHIMOTO Yasushi MATSUMOTO Takashi OHIRA Toshiyuki IDE 
Publication:   IEICE TRANSACTIONS on Communications
Publication Date: 1999/10/25
Vol. E82-B  No. 10  pp. 1659-1666
Type of Manuscript:  PAPER
Category: Satellite Communication
Keyword: 
S-bandmobile satellite communicationsatellite broadcastinghandheld terminalsgeostationary satellite
 Summary | Full Text:PDF(678.2KB)

New Design Approach to Multiple-Beam Forming Network for Beam-Steerable Phased Array Antennas
Fumio KIRA Kenji UENO Takashi OHIRA Hiroyo OGAWA 
Publication:   IEICE TRANSACTIONS on Electronics
Publication Date: 1999/07/25
Vol. E82-C  No. 7  pp. 1195-1201
Type of Manuscript:  Special Section PAPER (Special Issue on Microwave and Millimeter Wave Technology)
Category: Phased Arrays and Antennas
Keyword: 
multi-beam matrixbeam steeringBFNphased array antennasatellite communication onboard systems
 Summary | Full Text:PDF(1.3MB)

Higher-Order Analysis on Phase Noise Generation in Varactor-Tuned Oscillators-- Baseband Noise Upconversion in GaAs MESFET Oscillators--
Takashi OHIRA 
Publication:   IEICE TRANSACTIONS on Electronics
Publication Date: 1993/12/25
Vol. E76-C  No. 12  pp. 1851-1854
Type of Manuscript:  LETTER
Category: Microwave and Millimeter Wave Technology
Keyword: 
microwaveoscillatorphase noisevaractorperturbation
 Summary | Full Text:PDF(253.1KB)

A GaAs Monolithic Sampling Phase Frequency Comparator for Extending the Pull-In Range of Microwave Phase-Locked Oscillators
Tadao NAKAGAWA Tetsuo HIROTA Takashi OHIRA 
Publication:   IEICE TRANSACTIONS on Electronics
Publication Date: 1993/06/25
Vol. E76-C  No. 6  pp. 944-949
Type of Manuscript:  Special Section PAPER (Special Issue on Microwave and Millimeter-Wave Technology for Advanced Functions and Size-Reductions)
Category: 
Keyword: 
samplingphase frequency comparatorMMICKu-bandpull-in range
 Summary | Full Text:PDF(480.1KB)

Low-Noise MMIC Phase-Locked Oscillators Using an EXOR and a PFC
Tadao NAKAGAWA Hideo SUWAKI Takashi OHIRA 
Publication:   IEICE TRANSACTIONS on Electronics
Publication Date: 1993/06/25
Vol. E76-C  No. 6  pp. 950-954
Type of Manuscript:  Special Section PAPER (Special Issue on Microwave and Millimeter-Wave Technology for Advanced Functions and Size-Reductions)
Category: 
Keyword: 
phase noiseMMICPLOPFCEXOR
 Summary | Full Text:PDF(387.4KB)

Very Small MMIC Variable Frequency and Q Factor Active Bandpass Filters Using Novel Positive and Negative Feedback Design Techniques
Hideo SUWAKI Takashi OHIRA 
Publication:   IEICE TRANSACTIONS on Electronics
Publication Date: 1993/06/25
Vol. E76-C  No. 6  pp. 919-924
Type of Manuscript:  Special Section PAPER (Special Issue on Microwave and Millimeter-Wave Technology for Advanced Functions and Size-Reductions)
Category: 
Keyword: 
MMICfilterfeedbackQ-factorunity coupler
 Summary | Full Text:PDF(478.7KB)

Variational formula for Magnetostatic Wave Resonators and Its Applications
Takashi OHIRA Makoto TSUTSUMI Nobuaki KUMAGAI 
Publication:   IEICE TRANSACTIONS (1976-1990)
Publication Date: 1983/10/25
Vol. E66-E  No. 10  pp. 581-584
Type of Manuscript:  PAPER
Category: Microwaves and Millimeter Waves
Keyword: 
 Summary | Full Text:PDF(236.6KB)

Experimental Observation of Delay of Magnetostatic Waves in a Partially Magnetized YIG Slab
Makoto TSUTSUMI Yoshihiko MASAOKA Takashi OHIRA Nobuaki KUMAGAI 
Publication:   IEICE TRANSACTIONS (1976-1990)
Publication Date: 1979/07/25
Vol. E62-E  No. 7  pp. 481-482
Type of Manuscript:  LETTER
Category: Microwaves and Millimeter Waves
Keyword: 
 Summary | Full Text:PDF(152.2KB)