A 84-db wideband low-power variable gain amplifier

A wideband CMOS variable gain amplifier (VGA) with a wide gain tuning range for automatic gain control (AGC) in wireless communication systems is presented in this article. The VGA shows a maximum gain variation of 84 dB, its -3 dB bandwidth is 600 MHz at a maximum gain of 40 dB and 1.6 GHz at a minimum gain of -44 dB. The VGA gain is adjusted by applying external control voltage at the range of 350 mV to 1.6 V and is varied within 84 dB. The design's parameters were calculated and simulated for 180-nm CMOS technology. The VGA drains 4.5 mA from 1.8 V supply thus dissipating 8.1 mW.