Title :
A GaAs direct-conversion 1/4/spl pi/ shifted QPSK modulator IC with 0-28 dB variable attenuator for 1.9 GHz personal handy phone system
Author :
Sasaki, T. ; Otaka, S. ; Maeda, T. ; Umeda, T. ; Nishihori, K. ; Kameyama, A. ; Hirose, M. ; Kitaura, Y. ; Uchitomi, N.
Author_Institution :
ULSI Res. Center, Toshiba Corp., Kawasaki, Japan
fDate :
Oct. 29 1995-Nov. 1 1995
Abstract :
We have developed a GaAs direct-conversion 1/4/spl pi/ shifted QPSK modulator IC equipped with variable attenuators for controlling the output power level of the 1.9 GHz personal handy phone system (PHS). The IC was successfully demonstrated showing state-of-the-art performance with the image rejection ratio of more than 36 dB at a low input power of -10 dBm in the 1.9 GHz frequency range. By using the "Gate Current Control method by Pull-down FET\´s" (GCCPF), the equipped attenuators vary the output power from 0 dB to -28 dB by 4 dB step. The IC operates at a 2.7 V supply with the power dissipation of 259 mW. The 2.6/spl times/4.6 mm/sup 2/ chip with about 400 elements was fabricated by a 0.5 /spl mu/m WNx-gate BPLDD GaAs MESFET process.
Keywords :
III-V semiconductors; MESFET integrated circuits; UHF integrated circuits; cordless telephone systems; digital radio; gallium arsenide; mobile radio; modulators; personal communication networks; quadrature phase shift keying; 0.5 micron; 1.9 GHz; 2.7 V; 259 mW; GaAs; MESFET process; direct-conversion 1/4/spl pi/ shifted QPSK modulator IC; gate current control method; image rejection ratio; output power level; personal handy phone system; power dissipation; pull-down FETs; variable attenuator; Attenuators; Control systems; Current control; Frequency; Gallium arsenide; MESFETs; Power dissipation; Power generation; Power supplies; Quadrature phase shift keying;
Conference_Titel :
Gallium Arsenide Integrated Circuit (GaAs IC) Symposium, 1995. Technical Digest 1995., 17th Annual IEEE
Conference_Location :
San Diego, CA, USA
Print_ISBN :
0-7803-2966-X
DOI :
10.1109/GAAS.1995.529003
