Koichi TSUNEKAWA


A Novel Resonator Design for Q Factor Improvement Using Tightly-Coupled Parallel Coils in Coupled Magnetic Resonance Wireless Power Transfer
Cheng YANG Koichi TSUNEKAWA 
Publication:   IEICE TRANSACTIONS on Communications
Publication Date: 2016/03/01
Vol. E99-B  No. 3  pp. 685-694
Type of Manuscript:  PAPER
Category: Antennas and Propagation
Keyword: 
wireless power transfercoupled magnetic resonanceresonatorQ factortransfer efficiency
 Summary | Full Text:PDF(13.3MB)

Analysis and Performance Improvement of Independent Electric Coupled Resonance WPT System with Impedance Transformer
Cheng YANG Koichi TSUNEKAWA 
Publication:   IEICE TRANSACTIONS on Communications
Publication Date: 2015/04/01
Vol. E98-B  No. 4  pp. 630-637
Type of Manuscript:  PAPER
Category: Antennas and Propagation
Keyword: 
wireless power transferelectric coupled resonanceequivalent circuitimpedance matching
 Summary | Full Text:PDF(3.7MB)

Novel Downlink Beamforming Method Using Selective STBC with Common Eigenvectors for MIMO-OFDM Systems
Riichi KUDO Yasushi TAKATORI Kentaro NISHIMORI Koichi TSUNEKAWA 
Publication:   IEICE TRANSACTIONS on Communications
Publication Date: 2006/08/01
Vol. E89-B  No. 8  pp. 2170-2179
Type of Manuscript:  PAPER
Category: Wireless Communication Technologies
Keyword: 
MIMOeigenvectorOFDMachievable spectrum efficiencySTBCbeamformingmaximum Doppler frequencyfeedback overhead
 Summary | Full Text:PDF(1.4MB)

Series-Fed Beam-Scanning Antenna Employing Multi-Stage Configured Microstrip Antennas with Tunable Reactance Devices
Naoki HONMA Tomohiro SEKI Kenjiro NISHIKAWA Koichi TSUNEKAWA Kunio SAWAYA 
Publication:   IEICE TRANSACTIONS on Communications
Publication Date: 2005/06/01
Vol. E88-B  No. 6  pp. 2297-2304
Type of Manuscript:  Special Section PAPER (Special Section on 2004 International Symposium on Antennas and Propagation)
Category: 
Keyword: 
tunable reactance devicemicrostrip antennabeam scanningmulti-stagetraveling wave
 Summary | Full Text:PDF(925.6KB)

Frequency Correlation Characteristics Due to Antenna Configurations in Broadband MIMO Transmission
Kentaro NISHIMORI Nobuhiko TACHIKAWA Yasushi TAKATORI Riichi KUDO Koichi TSUNEKAWA 
Publication:   IEICE TRANSACTIONS on Communications
Publication Date: 2005/06/01
Vol. E88-B  No. 6  pp. 2438-2445
Type of Manuscript:  Special Section PAPER (Special Section on 2004 International Symposium on Antennas and Propagation)
Category: 
Keyword: 
MIMOfrequency correlationantenna arrangementOFDMdelay signalsangular spread
 Summary | Full Text:PDF(2.1MB)

High Performance Portable Telephone Antenna Employing a Flat-Type Open Sleeve
Koichi TSUNEKAWA 
Publication:   IEICE TRANSACTIONS on Electronics
Publication Date: 1996/05/25
Vol. E79-C  No. 5  pp. 693-698
Type of Manuscript:  Special Section PAPER (Special Issue on Microwave Devices for Mobile Communications)
Category: Passive Devices
Keyword: 
portable telephone antennalinear antennahigh gainmoment methodfinite element method
 Summary | Full Text:PDF(477.7KB)