4.6 mm2 chip with about 400 elements was fabricated by a 0.5 µm WNx-gate BPLDD GaAs MESFET process." />


Gate Current Control Method by Pull-Down FET's for 0-28 dB GaAs Variable Attenuator in Direct-Conversion Modulator IC for 1.9 GHz PHS

Tadahiro SASAKI  Shoji OTAKA  Tadahiko MAEDA  Toshiyuki UMEDA  Kazuya NISHIHORI  Atsushi KAMEYAMA  Mayumi HIROSE  Yoshiaki KITAURA  Naotaka UCHITOMI  

Publication
IEICE TRANSACTIONS on Electronics   Vol.E80-C   No.6   pp.794-799
Publication Date: 1997/06/25
Online ISSN: 
DOI: 
Print ISSN: 0916-8516
Type of Manuscript: Special Section PAPER (Special Issue on Microwave and Millimeterwave High-power Devices)
Category: 
Keyword: 
GaAs,  direct-conversion,  attenuator,  modulator,  MMIC,  MESFET,  personal handy phone system,  

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Summary: 
We have developed a GaAs direct-conversion π/4 shifted QPSK modulator IC equipped with variable attenuators for controlling the output power level of the 1.9 GHz Personal Handy Phone system in Japan (PHS). The IC was successfully demonstrated showing state-of-the-art performance with the image rejection ratio of more than 36 dBc at a low input power of -10 dBm in 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 power dissipation of 259 mW. The 2.64.6 mm2 chip with about 400 elements was fabricated by a 0.5 µm WNx-gate BPLDD GaAs MESFET process.