A SiGe HBT Variable Gain Amplifier for Wireless Receiver System with On-Chip Filter

Abstract

A using SiGe HBT variable gain amplifier (VGA) with filtering for wireless receiver system is presented in this paper. The VGA consists of three stages. The first stage is the gain control stage, and the second stage is the fixed gain stage. The third is the GM-C filter. The VGA is driven by a 3.3-V power supply, and linear gain control range varying is from 26 dB to 62dB. When control voltage varies from 0 to 1.8V. The input 1-dB compression point is -4dBm at minimum gain. The VGA is fabricated in a 0.5 μm = 80GHz and =90GHz silicon germanium heterojunction transistor technology.