Automatic control method for RF amplifier gain based on varying electrical bridge principle

Abstract

The invention relates to a method to control radio-frequency amplifier gain based on the deformation bridge theory. When the variance Delta Ubc of the differential voltage between a comparative end and a reference end equals to Delta k and also equals to 0, the high precision of the radio-frequency amplifier gain is stable, and the variance and the adjustment quantity of the radio frequency gain are balanced completely. When the variance and the adjustment quantity of the gain are balanced completely, parameters in the formula are as follows: Delta K1 (dB) is the variance of the radio frequency gain; Delta L2 (dB) is variance of attenuation of a digital control attenuator; Delta K3 (dB) is the signal gain of the reference end of an automatic gain control circuit; Delta K4(dB) is the signal gain of the comparative end of the automatic gain control circuit. The invention adopts the closed loop gain control proposal, and the circuit is simple. The gain control precision is high and is as high as 0.2 dB. The system structure is simple, and is designed rationally. The cost of development is low, and a lot of experimental expenses are saved. The invention solves the problems of poor stability of the radio-frequency amplifier gain, the complicated gain control circuit, low reliability of the system and high cost of development.

Description

technical field [0001] The invention belongs to the technical field of communication and electronic engineering, relates to an automatic gain control technology based on the principle of a modified electric bridge, and is used in a high-precision gain control system of a radio frequency amplifier. Background technique [0002] The existing RF amplifier gain stabilization schemes can be summarized as follows: [0003] Optical gain control, the circuit control scheme includes: the microwave input power is fed into the laser to generate an optical signal, which passes through an optical delay line and an optical gain controlled device to output an optical signal after gain adjustment, and then converts the optical signal into an electrical signal through a detector Output microwave power. Among them, the optical gain control circuit includes: optical splitter, optical fiber, electric optical attenuator, temperature monitoring, voltage comparison, data processing, and optical g...

AI Technical Summary

Problems solved by technology

[0008] In order to solve the problems of low gain control accuracy, complex gain control circuit, poor system reliability and high development cost of existing radio frequency amplifiers, the purpose of the present invention is to provide a high-precision control of radio frequency amplifier gain, simple circuit, high reliability, Develop a low-cost method for controlling the gain of radio frequency amplifiers based on the principle of deformed bridge

Images