Kenichi TAJIMA


A Compact RF Frontend Module of Active Phased Array Antenna for High SHF Wideband Massive MIMO in 5G
Hideyuki NAKAMIZO Shintaro SHINJO Koji TSUTSUMI Satoshi YAMAGUCHI Hideharu YOSHIOKA Akihiro OKAZAKI Akinori TAIRA Kenichi TAJIMA 
Publication:   
Publication Date: 2017/10/01
Vol. E100-C  No. 10  pp. 818-824
Type of Manuscript:  INVITED PAPER (Special Section on Microwave and Millimeter-Wave Technology)
Category: 
Keyword: 
massive MIMOactive phased array antennahigh SHFRF frontend5G
 Summary | Full Text:PDF(1.5MB)

Parallel Dual Modulus Prescaler with a Step Size of 0.5
Hideyuki NAKAMIZO Kenichi TAJIMA Ryoji HAYASHI Kenji KAWAKAMI Toshiya UOZUMI 
Publication:   IEICE TRANSACTIONS on Electronics
Publication Date: 2012/07/01
Vol. E95-C  No. 7  pp. 1189-1194
Type of Manuscript:  Special Section PAPER (Special Section on Recent Trends of Microwave Systems and Their Fundamental Technologies)
Category: 
Keyword: 
phase locked loopsdividerphase noisefractional-N frequency synthesizerdual modulus prescaler
 Summary | Full Text:PDF(1.2MB)

A Novel Spur Suppression Technique Using Three-Phase Holding Pulse for High-Frequency-Output Direct Digital Synthesizer
Kenichi TAJIMA Ryoji HAYASHI 
Publication:   IEICE TRANSACTIONS on Electronics
Publication Date: 2010/07/01
Vol. E93-C  No. 7  pp. 1014-1021
Type of Manuscript:  Special Section PAPER (Special Section on Recent Progress in Microwave and Millimeter-Wave Technologies)
Category: 
Keyword: 
direct digital synthesizerholding pulsedigital analog converter
 Summary | Full Text:PDF(1.2MB)

Novel Phase-Continuous Frequency Hopping Control for a Direct Frequency Synthesizer Using a Quadrature Mixer Driven by Two DDSs
Kenichi TAJIMA Ryoji HAYASHI Kenji ITOH Yoji ISOTA 
Publication:   IEICE TRANSACTIONS on Electronics
Publication Date: 2006/12/01
Vol. E89-C  No. 12  pp. 1829-1835
Type of Manuscript:  Special Section PAPER (Special Section on Emerging Microwave Techniques)
Category: Active Circuits/Devices/Monolithic Microwave Integrated Circuits
Keyword: 
frequency synthesizerdirect digital synthesizerquadrature mixerphase accumulatoroverflowphase
 Summary | Full Text:PDF(828.3KB)