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

Abstract

The invention relates to an automatic control method for the gain of a radio frequency amplifier based on the principle of a modified bridge. When the change amount of the differential voltage between the comparison terminal and the reference terminal is ΔUbc=Δk=0, the gain of the radio frequency amplifier obtains high precision and stability, and the change of the radio frequency gain When the gain change and adjustment are completely balanced: |ΔK1(dB)| / K3(dB)=|ΔL2(dB)| / K4(dB), the parameter in the formula: ΔK1 (dB) is the change of RF gain; ΔL2 (dB) is the change of attenuation of the digital attenuator; K3 (dB) is the signal gain of the reference end of the automatic gain control circuit; K4 (dB) is the signal gain of the comparison end of the automatic gain control circuit. The invention adopts the closed-loop gain control scheme, the circuit is simple; the gain control precision is high, and the gain control precision can reach 0.2dB; the system structure is simple, which is convenient for high reliability design; The problems of poor gain stability, complex gain control circuit, low system reliability and high development cost of the existing radio frequency amplifier are solved.

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

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