A Design Of Automatic Gain Control Circuit For Multi-mode GNSS Receiver

In recent years, the satellite navigation industry creating a huge economic effect has been developed very fast. It is now one of the world’s fastest growing three information industry. BeiDou navigation satellite system, which is developed and operated by China independently, is one of the four largest global navigation satellite system in the world. Mixing BeiDou and GPS together into a multi-frequency multimode satellite navigation chip, which will get more accurate and reliable positioning, has very important significance and commercial value.This paper has designed an automatic gain control circuit which can be used in multi-mode satellite navigation IC. The automatic gain control circuit adopts the structure of charge pump AGC, compared with the traditional peak detection AGC structure has the advantages of higher stability, faster response, and lower power consumption. The circuit uses a single link mode multiplexing structure, with minimal area and power consumption to achieve both zero intermediate frequency mode and low frequency mode.This design has been tipped out by TSMC0.18um CMOS process. The circuit can work both in zero intermediate frequency and low frequency mode with a stable output signal of800mV, a maximum gain of68dB, a dynamic range of50dB, a3dB bandwidth of60MHz. The power supply voltage is1.8V. Meet the system requirements of multi-mode satellite navigation chip.