A Large Gain Varialble range, Wide bandwidth Analog AGC Circuitry for a CMOS GPS Receiver

In this paper, a large gain variable range, wide-band automatic gain circuitry (AGC) is introduced. Because we employed a simple mean detection technique, the AGC loop dissipates less than 1mA current under 3.3V supply voltage, and acts as a bandpass filter due to a DC offset cancellation scheme. The whole circuitry is designed in 0.35um JAZZ CMOS process, including variable gain amplifiers(VGAs)、fixed gain amplifiers 、gain control and DC offset cancellation part. The AGC provides a process independent gain variable range of 56dB, with a 70us loop lock time.