Hiroaki SEKI


Design and Measurements of Two-Gain-Mode GaAs-BiFET MMIC Power Amplifier Modules with Small Phase Discontinuity for WCDMA Data Communications
Kazuya YAMAMOTO Miyo MIYASHITA Kenji MUKAI Shigeru FUJIWARA Satoshi SUZUKI Hiroaki SEKI 
Publication:   
Publication Date: 2018/01/01
Vol. E101-C  No. 1  pp. 65-77
Type of Manuscript:  PAPER
Category: Microwaves, Millimeter-Waves
Keyword: 
WCDMAMMICstep attenuatortwo gain modesdirectional couplerheterojunction bipolar transistors (HBTs)
 Summary | Full Text:PDF(2.3MB)

Experimental Study on CDMA GaAs HBT MMIC Power Amplifier Layout Design for Reducing Turn-On Delay in Transient Response
Kazuya YAMAMOTO Miyo MIYASHITA Takayuki MATSUZUKA Tomoyuki ASADA Kazunobu FUJII Satoshi SUZUKI Teruyuki SHIMURA Hiroaki SEKI 
Publication:   
Publication Date: 2017/06/01
Vol. E100-C  No. 6  pp. 618-631
Type of Manuscript:  PAPER
Category: Microwaves, Millimeter-Waves
Keyword: 
heterojunction bipolar transistors (HBTs)MMICCDMAparallel-amplifier-chain topologytransient responsethermal coupling
 Summary | Full Text:PDF(3.8MB)

Design and Measurements of Building Blocks Supporting a 1.9-GHz-Band BiFET MMIC Power Amplifier for WCDMA Handsets
Kazuya YAMAMOTO Takayuki MATSUZUKA Miyo MIYASHITA Kenichi HORIGUCHI Shigeo YAMABE Satoshi SUZUKI Hiroaki SEKI 
Publication:   IEICE TRANSACTIONS on Electronics
Publication Date: 2016/07/01
Vol. E99-C  No. 7  pp. 837-848
Type of Manuscript:  PAPER
Category: Microwaves, Millimeter-Waves
Keyword: 
MMICreference voltage generatorESD protectionthree power modesheterojunction bipolar transistors (HBTs)WCDMA
 Summary | Full Text:PDF(1.8MB)

A Current-Mirror-Based GaAs-HBT RF Power Detector Suitable for Base Terminal Monitoring in an HBT Power Stage
Kazuya YAMAMOTO Hitoshi KURUSU Miyo MIYASHTA Satoshi SUZUKI Hiroaki SEKI 
Publication:   IEICE TRANSACTIONS on Electronics
Publication Date: 2015/12/01
Vol. E98-C  No. 12  pp. 1150-1160
Type of Manuscript:  PAPER
Category: Microwaves, Millimeter-Waves
Keyword: 
power detectorcurrent-mirror circuitsheterojunction bipolar transistors (HBTs)WiMAXMMIC
 Summary | Full Text:PDF(4.2MB)

0.8-/1.5-GHz-Band WCDMA HBT MMIC Power Amplifiers with an Analog Bias Control Scheme
Kazuya YAMAMOTO Takayuki MATSUZUKA Miyo MIYASHITA Kenichi MAEDA Satoshi SUZUKI Hiroaki SEKI 
Publication:   IEICE TRANSACTIONS on Electronics
Publication Date: 2015/09/01
Vol. E98-C  No. 9  pp. 934-945
Type of Manuscript:  PAPER
Category: Microwaves, Millimeter-Waves
Keyword: 
analog bias controlemitter followercurrent injectionheterojunction bipolar transistors (HBTs)WCDMA
 Summary | Full Text:PDF(3.9MB)

A 3.5-GHz-Band GaAs HBT Stage-Bypass-Type Step-Gain Amplifier Using Base-Collector Diode Switches and Its Application to a WiMAX HBT MMIC Power Amplifier Module
Kazuya YAMAMOTO Miyo MIYASHITA Hitoshi KURUSU Yoshinobu SASAKI Satoshi SUZUKI Hiroaki SEKI 
Publication:   IEICE TRANSACTIONS on Electronics
Publication Date: 2015/07/01
Vol. E98-C  No. 7  pp. 716-728
Type of Manuscript:  PAPER
Category: Microwaves, Millimeter-Waves
Keyword: 
step gain controldiode switchesheterojunction bipolar transistors (HBTs)WiMAXMMIC
 Summary | Full Text:PDF(4.6MB)

A Low Quiescent Current CV/CC Parallel Operation HBT Power Amplifier for W-CDMA Terminals
Shintaro SHINJO Kazutomi MORI Hiro-omi UEDA Akira OHTA Hiroaki SEKI Noriharu SUEMATSU Tadashi TAKAGI 
Publication:   IEICE TRANSACTIONS on Electronics
Publication Date: 2003/08/01
Vol. E86-C  No. 8  pp. 1444-1450
Type of Manuscript:  Special Section PAPER (Special Issue on Microwave and Millimeter Wave Technology)
Category: 
Keyword: 
microwavepower amplifierheterojunction bipolar transistor (HBT)inductor base feedresistor base feed
 Summary | Full Text:PDF(1.6MB)