Design of a 1.8 V high frequency CMOS variable gain amplifier with a novel dB-linear gain structure

Abstract

In this paper, a novel dB-linear gain structure is introduced. Based on this structure, a high frequency and high dynamic range variable gain amplifier (VGA) is presented. The VGA circuit is designed for a satellite receiver application, operating from 950 MHz to 2.15 GHz. Simulation results were achieved using 0.18 /spl mu/m CMOS technology, and shown a good dB-linear control characteristic with dynamic gain range of 85 dB.