Receiver broadband large-dynamic-range automatic gain control circuit

Abstract

The invention discloses a receiver broadband large-dynamic-range automatic gain control circuit, which belongs to the technical field of radio frequency communication and comprises one pre-selection amplifying unit, four amplifying and filtering units 1, two amplifying and filtering units 2, two frequency converters, two automatic gain control units 1 and one automatic gain control unit. The receiver is of a superheterodyne structure, and uses a secondary frequency conversion scheme. The pre-selection amplifying unit comprises a filter bank composed of a switch and a band-pass filter, a low-noise amplifier and a low-pass filter. The amplifying and filtering unit 1 comprises a primary amplifier and a low-pass filter. The amplifying and filtering unit 2 comprises a primary amplifier and a band-pass filter. The automatic gain control unit 1 comprises a coupler, a detector, a voltage comparison unit and an attenuator. The automatic gain control unit 2 comprises a coupler, a detection control unit and a variable gain amplifier.

Description

technical field [0001] The invention relates to the technical field of radio frequency communication, in particular to a receiver wideband large dynamic automatic gain control circuit. Background technique [0002] With the development of wireless communication technology, higher and higher requirements are placed on the receiver. The introduction of the automatic gain control circuit can improve the overall performance of the receiver and gradually become an important part of the receiver. [0003] The automatic gain control function enables the receiver to automatically adjust the gain when receiving signals of different levels without external control, so that the signal output level is within the target range. There are many methods of automatic gain control, but each method has its own advantages and disadvantages: some are very simple, but the performance is poor; some methods have good performance, but are very cumbersome and complicated. However, it is difficult to...

AI Technical Summary

Problems solved by technology

[0005] The purpose of the present invention is to provide a receiver wideband large dynamic automatic gain control circuit, which solves the problem that the gain control range of the variable gain amplifier is small and the operating frequency range is narrow, and the broadband frequency and large dynamic power range will be affected when the attenuator is used. A large amount of collected data leads to a very complicated control program

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