Optimal Design of Broadband and Large Dynamic Range IF AGC Circuit

摘要

The bandwidth and the dynamic range is the critical performance parameter of IF AGC (Intermediate Frequency Automatic Gain Control) in wireless receiver. In order to design broadband and large dynamic range IF AGC circuit, the main functions and performance of the VGA (Variable Gain Amplifier) AD8367 and the logarithmic amplifier AD8318 are analyzed. A kind of a broadband large dynamic range IF AGC module is designed by using these two chips. Detail circuit is provided; key technology of AGC module is analyzed and the actual testing results are offered. Compared to the traditional AGC circuit, the module is simple; it has small size and obvious advantages in broadband and large dynamic range.