Takafumi YAMAJI


A Direct Conversion Receiver Adopting Balanced Three-Phase Analog System
Takafumi YAMAJI Takeshi UENO Tetsuro ITAKURA 
Publication:   IEICE TRANSACTIONS on Fundamentals of Electronics, Communications and Computer Sciences
Publication Date: 2010/02/01
Vol. E93-A  No. 2  pp. 367-374
Type of Manuscript:  Special Section PAPER (Special Section on Analog Circuit Techniques and Related Topics)
Category: 
Keyword: 
balanced 3-phase systemdirect conversion receiverΔΣADC
 Summary | Full Text:PDF

55-mW, 1.2-V, 12-bit, 100-MSPS Pipeline ADCs for Wireless Receivers
Tomohiko ITO Daisuke KUROSE Takeshi UENO Takafumi YAMAJI Tetsuro ITAKURA 
Publication:   IEICE TRANSACTIONS on Electronics
Publication Date: 2008/06/01
Vol. E91-C  No. 6  pp. 887-893
Type of Manuscript:  Special Section PAPER (Special Section on Analog Circuits and Related SoC Integration Technologies)
Category: 
Keyword: 
A/DADCpipelinelow poweramplifierpseudo-differential amplifierI/Q sharing
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1.2 V, 24 mW/ch, 10 bit, 80 MSample/s Pipelined A/D Converters
Takeshi UENO Tomohiko ITO Daisuke KUROSE Takafumi YAMAJI Tetsuro ITAKURA 
Publication:   IEICE TRANSACTIONS on Fundamentals of Electronics, Communications and Computer Sciences
Publication Date: 2008/02/01
Vol. E91-A  No. 2  pp. 454-460
Type of Manuscript:  Special Section PAPER (Special Section on Analog Circuit Techniques and Related Topics)
Category: 
Keyword: 
pipelined A/D converteramplifier sharingcommon-sourcecommon-mode feedforward
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A Low-Power Low-Noise Clock Signal Generator for Next-Generation Mobile Wireless Terminals
Akihide SAI Daisuke KUROSE Takafumi YAMAJI Tetsuro ITAKURA 
Publication:   IEICE TRANSACTIONS on Fundamentals of Electronics, Communications and Computer Sciences
Publication Date: 2008/02/01
Vol. E91-A  No. 2  pp. 557-560
Type of Manuscript:  Special Section LETTER (Special Section on Analog Circuit Techniques and Related Topics)
Category: 
Keyword: 
clock generatorjitterPLLAnalog-to-Digital Converter (ADC)
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A 1.2-V, 12-bit, 200 MSample/s Current-Steering D/A Converter in 90-nm CMOS
Takeshi UENO Takafumi YAMAJI Tetsuro ITAKURA 
Publication:   IEICE TRANSACTIONS on Fundamentals of Electronics, Communications and Computer Sciences
Publication Date: 2007/02/01
Vol. E90-A  No. 2  pp. 365-371
Type of Manuscript:  Special Section PAPER (Special Section on Analog Circuit Techniques and Related Topics)
Category: 
Keyword: 
D/A convertercurrent steeringlow voltageparasitic resistancetree structure
 Summary | Full Text:PDF

Low-Power Design of 10-bit 80-MSPS Pipeline ADCs
Tomohiko ITO Daisuke KUROSE Takeshi UENO Takafumi YAMAJI Tetsuro ITAKURA 
Publication:   IEICE TRANSACTIONS on Fundamentals of Electronics, Communications and Computer Sciences
Publication Date: 2006/07/01
Vol. E89-A  No. 7  pp. 2003-2008
Type of Manuscript:  PAPER
Category: Analog Signal Processing
Keyword: 
analog-to-digital converterpipelineamplifier sharing
 Summary | Full Text:PDF

Nonlinear Analysis of Bipolar Harmonic Mixer for Direct Conversion Receivers
Hiroshi TANIMOTO Ryuta ITO Takafumi YAMAJI 
Publication:   IEICE TRANSACTIONS on Electronics
Publication Date: 2005/06/01
Vol. E88-C  No. 6  pp. 1203-1211
Type of Manuscript:  Special Section PAPER (Special Section on Analog Circuit and Device Technologies)
Category: RF
Keyword: 
harmonic mixerBHMIXtheoretical analysisdown conversion mixerconversion gainIIP3IIP2self-mixingdc offsetnoise analysiscyclostationary noise
 Summary | Full Text:PDF

A 2-GHz Down-Converter with 3-dB Bandwidth of 600 MHz Using LO Signal Suppressing Output Buffer
Osamu WATANABE Takafumi YAMAJI Tetsuro ITAKURA Ichiro HATTORI 
Publication:   IEICE TRANSACTIONS on Fundamentals of Electronics, Communications and Computer Sciences
Publication Date: 2002/02/01
Vol. E85-A  No. 2  pp. 286-292
Type of Manuscript:  Special Section PAPER (Special Section on Analog Circuit Techniques and Related Topics)
Category: 
Keyword: 
analog signal processingintegrated circuitdown-converter
 Summary | Full Text:PDF

A Low Offset 1.9-GHz Direct Conversion Receiver IC with Spurious Free Dynamic Range of over 67 dB
Shoji OTAKA Takafumi YAMAJI Ryuichi FUJIMOTO Hiroshi TANIMOTO 
Publication:   IEICE TRANSACTIONS on Fundamentals of Electronics, Communications and Computer Sciences
Publication Date: 2001/02/01
Vol. E84-A  No. 2  pp. 513-519
Type of Manuscript:  Special Section PAPER (Special Section on Analog Circuit Techniques Supporting the System LSI Era)
Category: 
Keyword: 
direct conversion receiverdouble balanced mixervariable gain amplifieron-chip balun90 phase-shifter
 Summary | Full Text:PDF

A Digital-to-RF Converter Architecture Suitable for a Digital-to-RF Direct-Conversion Software Defined Radio Transmitter
Takafumi YAMAJI Akira YASUDA Hiroshi TANIMOTO Yasuo SUZUKI 
Publication:   IEICE TRANSACTIONS on Communications
Publication Date: 2000/06/25
Vol. E83-B  No. 6  pp. 1254-1260
Type of Manuscript:  Special Section PAPER (Special Issue on Software Defined Radio and Its Technologies)
Category: 
Keyword: 
DACdigital-to-RF direct-conversionsoftware defined radioΔΣ modulation
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System-Level Compensation Approach to Overcome Signal Saturation, DC Offset, and 2nd-Order Nonlinear Distortion in Linear Direct Conversion Receiver
Hiroshi TSURUMI Miyuki SOEYA Hiroshi YOSHIDA Takafumi YAMAJI Hiroshi TANIMOTO Yasuo SUZUKI 
Publication:   IEICE TRANSACTIONS on Electronics
Publication Date: 1999/05/25
Vol. E82-C  No. 5  pp. 708-716
Type of Manuscript:  Special Section PAPER (Special Issue on Low Distortion Technology for Microwave Devices and Circuits)
Category: 
Keyword: 
direct conversion receiverlinear modulation schemeRF stage gain controlinitial burst acquisitionDC offset canceler2nd-order intermodulation distortion
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An Offset-Compensated CMOS Programmable Gain Amplifier
Takafumi YAMAJI Tetsuro ITAKURA 
Publication:   IEICE TRANSACTIONS on Fundamentals of Electronics, Communications and Computer Sciences
Publication Date: 1997/02/25
Vol. E80-A  No. 2  pp. 353-355
Type of Manuscript:  Special Section LETTER (Special Section on Analog Circuit Techniques for System-on-Chip Integration)
Category: 
Keyword: 
DC offsetoffset compensationTDMAanalog CMOS circuitdigital cellular
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