Title :
High dynamic range variable gain amplifier for CDMA applications
Author :
Kasashima, M. ; Tachi, S. ; Tanaka, K.
Author_Institution :
Electron. Components Group, Oki Electr. Ind. Co. Ltd., Tokyo, Japan
Abstract :
A new attenuator and threshold voltage (Vth) compensation circuits using GaAs MESFET were designed and developed and this circuit was applied to develop a variable gain amplifier (VGA) for CDMA cellular phone systems. This VGA is packaged in an 8-pin plastic package and demonstrated high dynamic variable gain range (80 dB/100 MHz 70 dB/250 MHz 55 dB/500 MHz). High gain of 60 dB is observed for 85 MHz with low power consumption (Vdd=+2.7 V, Idd=6 mA). Since depletion mode MESFETs are used no negative supply is needed for gain control.
Keywords :
III-V semiconductors; MESFET integrated circuits; MMIC amplifiers; automatic gain control; cellular radio; code division multiple access; compensation; gallium arsenide; integrated circuit packaging; 2.7 V; 55 to 80 dB; 6 mA; CDMA applications; GaAs; attenuator; cellular phone systems; depletion mode MESFETs; dynamic range; gain control; plastic package; power consumption; threshold voltage compensation circuits; variable gain amplifier; Attenuators; Cellular phones; Dynamic range; Energy consumption; Gain; Gallium arsenide; MESFET circuits; Multiaccess communication; Plastic packaging; Threshold voltage;
Conference_Titel :
Radio Frequency Integrated Circuits (RFIC) Symposium, 1997., IEEE
Conference_Location :
Denver, CO, USA
Print_ISBN :
0-7803-4063-9
DOI :
10.1109/RFIC.1997.598765
