90dB Wide Dynamice Range Controllable AGC System Design And Its Application In Radar Remote Measurement Platform

AGC system components are widely used as a basis for radar / communication receivers, smart antennas, digital cameras, many aspects, such as hearing aids. The article summarized the existing technology of AGC and analyzed main parameters of AGC: dynamic range, the establishment loop time. According to the given multi-stage AGC's extreme range and impact factors, we proposed a method expanding the dynamic range. Pre-amplification technology is adopted to expand the dynamic range of sampled data, thus improving the system dynamic range. For analog AGC reference level adjustment difficulties and the lack of computing differential comparison, digital-level matching techniques is introduced to achieve dynamic output gain control. So, we design a wide dynamic range controllable AGC system which is two– stage.Experiments show that the system's input dynamic range reachs 90dB when it output gain is between ? 3.52dBm±0.05. System's input dynamic range can reach 100dB with VGA fully used when output gain floating scope of the system is between ? 3.52dBm±1.5. Compared with the exsiting systems, our design system has 15~30 expansion in the dynamic range. So sanmping pre-amplification and digital contrast hybrid technology can effectively expand the dynamic range of AGC system.