Koichi OGAWA


Regression-Based Channel Capacity for the Evaluation of 2×2 MIMO Antennas
Kazuhiro HONDA Takeshi KITAMURA Kun LI Koichi OGAWA 
Publication:   
Publication Date: 2017/02/01
Vol. E100-B  No. 2  pp. 323-335
Type of Manuscript:  PAPER
Category: Antennas and Propagation
Keyword: 
MIMO antennachannel capacityMonte Carlo methodmultivariate regression analysis
 Summary | Full Text:PDF(2.6MB)

Wavelength Analysis Using Equivalent Circuits in a Fast and Slow Wave Waffle-Iron Ridge Guide
Hideki KIRINO Kazuhiro HONDA Kun LI Koichi OGAWA 
Publication:   
Publication Date: 2017/02/01
Vol. E100-B  No. 2  pp. 219-226
Type of Manuscript:  Special Section PAPER (Special Section on Antenna and Propagation Technologies Contributing to Realization of Next Generation Wireless Systems)
Category: 
Keyword: 
waffle-ironridgewaveguidefast waveslow wavewavelengtharray antenna
 Summary | Full Text:PDF(1.3MB)

Three-Dimensional Over-The-Air Assessment for Vertically Arranged MIMO Array Antennas
Kun LI Kazuhiro HONDA Koichi OGAWA 
Publication:   IEICE TRANSACTIONS on Communications
Publication Date: 2016/01/01
Vol. E99-B  No. 1  pp. 167-176
Type of Manuscript:  PAPER
Category: Antennas and Propagation
Keyword: 
MIMO-OTAfading emulatorvertically arranged array antennathree-dimensional channel model
 Summary | Full Text:PDF(2.7MB)

Channel Capacity Evaluation of MIMO Antenna Based on Eigenvalues of S-Parameter
Naoki HONMA Kentaro MURATA Hiroshi SATO Koichi OGAWA Yoshitaka TSUNEKAWA 
Publication:   IEICE TRANSACTIONS on Communications
Publication Date: 2016/01/01
Vol. E99-B  No. 1  pp. 95-103
Type of Manuscript:  Special Section PAPER (Special Section on Recent Progress in Antennas, Propagation and Wireless Systems Related to Topics in ISAP2014)
Category: Antennas and Propagation
Keyword: 
MIMOcapacityS-parameter
 Summary | Full Text:PDF(3.2MB)

Weighted-Polarization Wearable MIMO Antenna with Three Orthogonally Arranged Dipoles Based on RF Signal Processing
Kazuhiro HONDA Kun LI Koichi OGAWA 
Publication:   IEICE TRANSACTIONS on Communications
Publication Date: 2016/01/01
Vol. E99-B  No. 1  pp. 58-68
Type of Manuscript:  Special Section PAPER (Special Section on Recent Progress in Antennas, Propagation and Wireless Systems Related to Topics in ISAP2014)
Category: Antennas and Propagation
Keyword: 
weighted-polarization wearable MIMO antennaRF signal processingchannel capacityshadowing
 Summary | Full Text:PDF(2.9MB)

Rice Channel Realization for BAN Over-The-Air Testing Using a Fading Emulator with an Arm-Swinging Dynamic Phantom
Kun LI Kazuhiro HONDA Koichi OGAWA 
Publication:   IEICE TRANSACTIONS on Communications
Publication Date: 2015/04/01
Vol. E98-B  No. 4  pp. 543-553
Type of Manuscript:  Special Section PAPER (Special Section on Innovation of Medical Information and Communication Technology for Dependable Society)
Category: 
Keyword: 
BAN-OTA testingRice channelfading emulatorK-factordynamic phantom
 Summary | Full Text:PDF(4.3MB)

A Spatial Fading Emulator for Evaluation of MIMO Antennas in a Cluster Environment
Tsutomu SAKATA Atsushi YAMAMOTO Koichi OGAWA Hiroshi IWAI Jun-ichi TAKADA Kei SAKAGUCHI 
Publication:   IEICE TRANSACTIONS on Communications
Publication Date: 2014/10/01
Vol. E97-B  No. 10  pp. 2127-2135
Type of Manuscript:  Special Section PAPER (Special Section on Recent Progress in Measurement and Design Techniques on Antennas, Propagation and Wireless Systems)
Category: 
Keyword: 
fading emulatorclusterangular power spectrumOTAhandset antennaMIMOchannel capacity
 Summary | Full Text:PDF(2.4MB)

Shadowing-Fading BER Characterization of a BAN Diversity Antenna Based on Statistical Measurements of the Human Walking Motion
Kazuhiro HONDA Kun LI Koichi OGAWA 
Publication:   IEICE TRANSACTIONS on Communications
Publication Date: 2013/10/01
Vol. E96-B  No. 10  pp. 2530-2541
Type of Manuscript:  Special Section PAPER (Special Section on Recent Progress in Antennas and Propagation in Conjunction with Main Topics of ISAP2012)
Category: Wireless Communication Technologies
Keyword: 
body area network (BAN)diversity antennawalking motionshadowingmultipath fadingBER analysis
 Summary | Full Text:PDF(2.9MB)

Effects of Received Power Imbalance on the Diversity Gain of a Digital TV MRC Array Antenna
Koichi OGAWA Kazuhiro HONDA 
Publication:   IEICE TRANSACTIONS on Communications
Publication Date: 2013/03/01
Vol. E96-B  No. 3  pp. 811-819
Type of Manuscript:  PAPER
Category: Antennas and Propagation
Keyword: 
maximum ratio combining (MRC)diversity antennapower imbalancedigital TVMonte Carlo simulation
 Summary | Full Text:PDF(1.3MB)

Performance Analysis of MIMO Schemes in Residential Home Environment via Wideband MIMO Propagation Measurement
Gia Khanh TRAN Nguyen Dung DAO Kei SAKAGUCHI Kiyomichi ARAKI Hiroshi IWAI Tsutomu SAKATA Koichi OGAWA 
Publication:   IEICE TRANSACTIONS on Fundamentals of Electronics, Communications and Computer Sciences
Publication Date: 2010/04/01
Vol. E93-A  No. 4  pp. 814-829
Type of Manuscript:  PAPER
Category: Communication Theory and Signals
Keyword: 
MIMO-OFDMwideband MIMO channel measurementresidential home environmentthroughput performance evaluation
 Summary | Full Text:PDF(7.2MB)

A Low Distortion and Low Noise Differential Amplifier Suitable for 3G LTE Applications Using the Even- and Odd-Mode Impedance Differences of a Bias Circuit
Toshifumi NAKATANI Koichi OGAWA 
Publication:   IEICE TRANSACTIONS on Electronics
Publication Date: 2008/06/01
Vol. E91-C  No. 6  pp. 844-853
Type of Manuscript:  Special Section PAPER (Special Section on Analog Circuits and Related SoC Integration Technologies)
Category: 
Keyword: 
3rd order intermodulationnoise figuredifferential amplifier2-tone difference frequencyeven- and odd-mode impedance differenceinput bias circuit3rd generation long term evolution
 Summary | Full Text:PDF(1MB)

A Variable Phase Shifter Using a Movable Waffle Iron Metal Plate and Its Applications to Phased Array Antennas
Hideki KIRINO Koichi OGAWA Takeshi OHNO 
Publication:   IEICE TRANSACTIONS on Communications
Publication Date: 2008/06/01
Vol. E91-B  No. 6  pp. 1773-1782
Type of Manuscript:  Special Section PAPER (Special Section on 2007 International Symposium on Antennas and Propagation)
Category: Antennas
Keyword: 
waffle ironPMC (Perfect Magnetic Conductor)phase shifterphased array antennavehicle radar
 Summary | Full Text:PDF(591.5KB)

Empirical Investigation of the LOS Propagation Characteristics on an Undulating Road for Millimeter Wave Inter-Vehicle Communication
Atsushi YAMAMOTO Koichi OGAWA Hiroshi SHIRAI 
Publication:   IEICE TRANSACTIONS on Electronics
Publication Date: 2007/09/01
Vol. E90-C  No. 9  pp. 1807-1815
Type of Manuscript:  Special Section PAPER (Special Section on Microwave and Millimeter-Wave Technology)
Category: Antennas/Systems
Keyword: 
ITSinter-vehicle communicationsLOSroad undulation
 Summary | Full Text:PDF(1.1MB)

IM3 Cancellation Method Using Current Feedback Suitable for a Multi-Stage RFIC Amplifier
Toshifumi NAKATANI Koichi OGAWA 
Publication:   IEICE TRANSACTIONS on Electronics
Publication Date: 2007/06/01
Vol. E90-C  No. 6  pp. 1209-1221
Type of Manuscript:  Special Section PAPER (Special Section on Analog Circuits and Related SoC Integration Technologies)
Category: 
Keyword: 
feedback amplifier3rd order Intermodulation distortionIM3 cancellation techniqueIM3 phaseintegrated circuit designVolterra seriesload-pull measurement2nd order non-linearity
 Summary | Full Text:PDF(1.9MB)

Simple Modeling of an Abdomen of Pregnant Women and Its Application to SAR Estimation
Hiroki KAWAI Koichi ITO Masaharu TAKAHASHI Kazuyuki SAITO Takuya UEDA Masayoshi SAITO Hisao ITO Hisao OSADA Yoshio KOYANAGI Koichi OGAWA 
Publication:   IEICE TRANSACTIONS on Communications
Publication Date: 2006/12/01
Vol. E89-B  No. 12  pp. 3401-3410
Type of Manuscript:  PAPER
Category: Electromagnetic Compatibility(EMC)
Keyword: 
fetuspregnant womenamniotic fluidSARFDTD method
 Summary | Full Text:PDF(1MB)

Attenuation Characteristics of the SAR in a COST244 Phantom with Different EM Source Locations and Sizes
Shoichi KAJIWARA Atsushi YAMAMOTO Koichi OGAWA Akihiro OZAKI Yoshio KOYANAGI 
Publication:   IEICE TRANSACTIONS on Communications
Publication Date: 2005/06/01
Vol. E88-B  No. 6  pp. 2391-2400
Type of Manuscript:  Special Section PAPER (Special Section on 2004 International Symposium on Antennas and Propagation)
Category: 
Keyword: 
SARattenuation characteristicCOST244 phantomlossy mediumspatial spread of energy
 Summary | Full Text:PDF(1.9MB)

A Simple Method for the Measurement of the Phase and Power of 3rd-Order Inter-Modulation Components of the Output of Multi-Stage Power Amplifiers
Toshifumi NAKATANI Toru MATSUURA Koichi OGAWA 
Publication:   IEICE TRANSACTIONS on Electronics
Publication Date: 2004/05/01
Vol. E87-C  No. 5  pp. 749-761
Type of Manuscript:  Special Section PAPER (Special Section on Advances in Characterization and Measurement Technologies for Microwave and Millimeter-Wave Materials, Devices and Circuits)
Category: Active Devices and Circuits
Keyword: 
3rd-order inter-modulation distortionphase of IM3 signaldissipation powervector signal analyzermulti-stage cascaded power amplifierVolterra seriesasymmetry of IM3 sidebands
 Summary | Full Text:PDF(875.4KB)

A Three-Mode Switched-LNA Using a Low Parasitic Capacitance MOSFET Switch
Toshifumi NAKATANI Koichi OGAWA Junji ITOH Ikuo IMANISHI 
Publication:   IEICE TRANSACTIONS on Electronics
Publication Date: 2003/06/01
Vol. E86-C  No. 6  pp. 1032-1040
Type of Manuscript:  Special Section PAPER (Special Issue on Devices and Circuits for Next Generation Multi-Media Communication Systems)
Category: 
Keyword: 
low noise amplifiernoise figureMOSFET switchparasitic capacitance3rd-order intercept pointdissipation powercross-modulation
 Summary | Full Text:PDF(1.1MB)

Proposal for a Slot Pair Array Having an Invariant Main Beam Direction with a Cosecant Radiation Pattern Using a Post-Wall Waveguide
Takeshi OHNO Koichi OGAWA Toshihiro TERAOKA Jiro HIROKAWA 
Publication:   IEICE TRANSACTIONS on Electronics
Publication Date: 2003/02/01
Vol. E86-C  No. 2  pp. 176-183
Type of Manuscript:  Special Section PAPER (Special Issue on Circuit and Device Technology for High-Speed Wireless Communication)
Category: Antenna (Slot)
Keyword: 
FWAmain beam directiontraveling wavecosecant radiation patternTalor radiation pattern
 Summary | Full Text:PDF(782.4KB)

An Excellent Cost-Performance Antenna Duplexer for 26 GHz FWA Systems
Toshio ISHIZAKI Toshihiro TERAOKA Koichi OGAWA 
Publication:   IEICE TRANSACTIONS on Electronics
Publication Date: 2001/10/01
Vol. E84-C  No. 10  pp. 1515-1520
Type of Manuscript:  Special Section PAPER (Special Issue on Millimeter-Wave Circuits and Fabrication Technologies Opening up the 21st Century)
Category: 
Keyword: 
FWAduplexerE-plane filtercirculatorwaveguide
 Summary | Full Text:PDF(885.6KB)

A Low-Profile Bi-Directional Cavity Antenna with Broadband Impedance Characteristics
Atsushi YAMAMOTO Hiroshi IWAI Toshimitsu MATSUYOSHI Koichi OGAWA 
Publication:   IEICE TRANSACTIONS on Communications
Publication Date: 2001/09/01
Vol. E84-B  No. 9  pp. 2490-2497
Type of Manuscript:  Special Section PAPER (Special Issue on Innovation in Antennas and Propagation for Expanding Radio Systems)
Category: Mobile Antennas
Keyword: 
bi-directional radiation patterncavity antennaIMT-2000picocell base station
 Summary | Full Text:PDF(756KB)

Introduction of a Narrower HPBW BS Antenna to Millimetre Wave P-MP FWA Systems: Performance Validation in Terms of C/N, C/I and the Visibility
Hiroshi KANNO Toshihiro TERAOKA Toshio ISHIZAKI Koichi OGAWA 
Publication:   IEICE TRANSACTIONS on Communications
Publication Date: 2001/03/01
Vol. E84-B  No. 3  pp. 359-367
Type of Manuscript:  Special Section PAPER (Special Issue on Innovative Mobile Communication Technologies at the Dawn of the 21st Century)
Category: 
Keyword: 
millimetre-waveFWAbase station antennavisibility
 Summary | Full Text:PDF(714.5KB)

A Study of a Laminated Band Elimination Filter Comprising Coupled-Line Resonators Using Low Temperature Co-Fired Ceramics
Hideyuki MIYAKE Shoichi KITAZAWA Toshio ISHIZAKI Koichi OGAWA Ikuo AWAI 
Publication:   IEICE TRANSACTIONS on Electronics
Publication Date: 1999/07/25
Vol. E82-C  No. 7  pp. 1104-1109
Type of Manuscript:  Special Section PAPER (Special Issue on Microwave and Millimeter Wave Technology)
Category: Passive Devices and Circuits
Keyword: 
band elimination filtercoupled-line resonatorslaminated filterLTCC
 Summary | Full Text:PDF(1.3MB)

Practical Design Procedure of an Elliptic Function Dual-Mode Cavity Filter Coupled through a Non-zero-Thick Septum
Toshio ISHIZAKI Koichi OGAWA Hideyuki MIYAKE 
Publication:   IEICE TRANSACTIONS on Electronics
Publication Date: 1998/06/25
Vol. E81-C  No. 6  pp. 916-923
Type of Manuscript:  Special Section PAPER (Special Issue on Microwave and Millimeter-Wave Module Technology)
Category: Passive Element
Keyword: 
dual-modeelliptic function filtercoupling apertureseptumthickness
 Summary | Full Text:PDF(608.4KB)

A Beam Tilt Dipole Array Antenna for Indoor Mobile Applications
Koichi OGAWA Tomoki UWANO 
Publication:   IEICE TRANSACTIONS on Electronics
Publication Date: 1996/05/25
Vol. E79-C  No. 5  pp. 685-692
Type of Manuscript:  Special Section PAPER (Special Issue on Microwave Devices for Mobile Communications)
Category: Passive Devices
Keyword: 
beam tiltsector beamdipole array antennaindoor base station
 Summary | Full Text:PDF(702.7KB)