Title :
A 380-MHz CMOS linear-in-dB signal-summing variable gain amplifier with gain compensation techniques for CDMA systems
Author :
Watanabe, O. ; Otaka, S. ; Ashida, M. ; Itakura, T.
Author_Institution :
Corporate R&D Center, Toshiba Corp., Kawasaki, Japan
Abstract :
A linear-in-dB signal-summing Variable Gain Amplifier (VGA) is fabricated in 0.25 /spl mu/m CMOS technology. Two gain compensation techniques are proposed in order to compensate the gain deviations due to the MOSFET characteristic which has a square-law characteristic or an exponential-law characteristic determined by its current density. Temperature compensation techniques are also proposed. A gain range of 80 dB, a gain error of within /spl plusmn/3 dB, an NF of 11 dB are obtained at 380 MHz by measurement.
Keywords :
CMOS analogue integrated circuits; UHF amplifiers; UHF integrated circuits; code division multiple access; compensation; gain control; 0.25 micron; 11 dB; 380 MHz; 80 dB; CMOS technology; MOSFET characteristic; current density; exponential-law characteristic; gain compensation techniques; linear-in-dB VGA; signal-summing VGA; square-law characteristic; temperature compensation techniques; variable gain amplifier; wideband CDMA systems; Bipolar transistors; CMOS technology; Dynamic range; Equations; Frequency; Gain; MOSFET circuits; Multiaccess communication; Research and development; Voltage control;
Conference_Titel :
VLSI Circuits Digest of Technical Papers, 2002. Symposium on
Conference_Location :
Honolulu, HI, USA
Print_ISBN :
0-7803-7310-3
DOI :
10.1109/VLSIC.2002.1015066
