Method for controlling gain and attenuation of broadband low-noise amplifier

Abstract

The invention provides a method for controlling gain and attenuation of a broadband low-noise amplifier. A main gain amplifier and an auxiliary gain amplifier are arranged between a radio frequency input end and an output end of the amplifier, an output end of the main gain amplifier is connected with a main adjustable attenuator, an output end of the main adjustable attenuator is connected with a multilevel radio frequency gain amplifier, the multilevel radio frequency gain amplifier is connected with the output end of the amplifier, an input end of the auxiliary gain amplifier is connected with an auxiliary adjustable attenuator, the auxiliary adjustable attenuator and the auxiliary gain amplifier are connected with the main gain amplifier in parallel, the main gain amplifier and the auxiliary gain amplifier respectively have a fixed gain value. through the on / off of the main gain amplifier and the auxiliary gain amplifier, the respective adjustment values of the main adjustable attenuator, the auxiliary adjustable attenuator and the multilevel radio frequency gain amplifier are combined at the output end of the amplifier to obtain a linear gain or attenuation value; meanwhile, the gain value and the attenuation value range are enlarged, thus the dynamic range can be greatly increased, strong interference can be restrained and nonlinear distortion can be eliminated.

Description

technical field [0001] The invention relates to the electrical field, in particular to a microwave circuit, in particular to a method for controlling the gain and attenuation of a broadband low-noise amplifier. Background technique [0002] In the prior art, wireless access radio frequency circuits are widely used to implement wireless connection and information exchange between devices. Low noise amplifiers are an integral part of the front end of an RF receiver. In order to suppress the impact of noise on the system at various levels behind, the low noise amplifier needs to have a certain gain, but too large gain will overload the mixer behind the broadband low noise amplifier, resulting in nonlinear distortion. At the same time, the broadband low noise amplifier It is a small signal linear amplifier. Due to the influence of the transmission path, the strength of the signal changes. When receiving the signal, there is often strong interference. Therefore, the gain and att...

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Problems solved by technology

[0003] The purpose of the present invention is to provide a method for controlling the gain and attenuation of the broadband low noise amplifier, and the method for controlling the gain and attenuation of the broadband low noise amplifier will solve the problem that the broadband low noise amplifier in the prior art produces abnormal Technical issues with linear distortion and low dynamic range

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