AGC automatic gain control device for very high frequency data communication

Abstract

The invention discloses an AGC (Automatic Gain Control) device for very high frequency data communication, relates to the technical field of automatic gain control, and solves the problem that in the prior art, long response time is needed for meeting stable signal power of abrupt change signals, and the error rate is increased when the requirement for quick response time is met. The device comprises a gain control module, an envelope detection module, a threshold comparison module, a filtering module, a control module, an A / D sampling module and the like. The input end of the envelope detection module is connected with the output end of the gain control module, and the output end of the envelope detection module is connected with the input end of the threshold comparison module and the input end of the A / D sampling module; the output end of the A / D sampling module is connected with the input end of the control module, the output end of the threshold comparison module is connected with the input end of the filtering module, the output end of the filtering module is connected with the gain control module, and the output end of the control module is connected with the input end of the filtering module; and through a fast and slow mode switching mode, fast response control of abrupt change signals is completed in a short time, and power level stability can be kept after fast response.

Description

technical field [0001] The present application relates to the technical field of automatic gain control, in particular to an AGC automatic gain control device for VHF data communication. Background technique [0002] As the distance between the receiver and the ground station changes, the signal power received by the antenna end has a large range of variation. In order to correctly demodulate the baseband signal, the front end of the receiver needs to automatically adjust its gain according to the strength of the input signal, so as to obtain a relatively stable output signal. This function is realized by the automatic gain control loop in the system. There are generally two forms of automatic gain control loops, one is an open-loop automatic gain control system and a closed-loop automatic gain control system. [0003] The traditional open-loop automatic gain control system is sensitive to changes in system parameters, and the output signal is prone to fluctuations, and can...

AI Technical Summary

Problems solved by technology

[0004] The embodiment of the present application provides an AGC automatic gain control device for VHF data communication, which solves the problem in the prior art that the response time is relatively long in order to stabilize the output signal for a sudden change signal, and if a short response is satisfied Time requirements will cause fluctuations in the control voltage, which will cause the increase of the error of the signal symbol phase and the increase of the bit error rate of the signal demodulation. It realizes the rapid response control of a large-scale mutation signal in a short period of time, and in the Ability to keep power levels stable after fast response

Images