Multimode radio AGC receive control technology and FPGA implementation

Automatic Gain Control (AGC) is widely used in electronic systems, and in airborne radios, the distance of the airborne radio from the radiation source may vary considerably, and there is significant fading in the transmission of electromagnetic waves through space, as well as other disturbances to the airborne radio, resulting in significant variations and ups and downs in the signal strength at the input of the airborne radio. However, airborne radio amplifiers and analogue-to-digital converters (ADCs) can usually only handle signals with small variations in amplitude, and a signal that is too strong will cause the device to operate in the nonlinear region, while a signal that is too small will result in signal reception failure. In this regard, a three-stage cascaded digital AGC control model for multimode radios is proposed, and corresponding control schemes are designed for AM AM signals, FM and BPSK constant envelope signals. The proposed method is developed and verified in FPGA to verify the effectiveness of the method.