Radio frequency receiver with automatic gain control

Abstract

The invention relates to a radio frequency receiver with automatic gain control, which comprises a wiring terminal used for receiving a radio frequency signal, the wiring terminal is connected with a low-noise amplifier, the low-noise amplifier is connected with a voltage-current converter, the voltage-current converter is connected with two frequency mixers, each frequency mixer is connected with a trans-impedance amplifier, and the trans-impedance amplifier is connected with a power amplifier. Each trans-impedance amplifier is connected with a low-pass filter, each low-pass filter is connected with a variable gain amplifier, each variable gain amplifier is connected with a digital-to-analog converter, and the two digital-to-analog converters are jointly connected with a processing control module; the low-noise amplifier, the voltage-current converter, the frequency mixer, the trans-impedance amplifier and the variable gain amplifier are used for coarsely and finely adjusting gain coefficients; and the processing control module is used for calculating the frequency of the radio frequency signal and controlling the low-noise amplifier, the voltage-current converter, the frequency mixer, the trans-impedance amplifier and the variable gain amplifier to adjust the gain coefficient. According to the invention, a wide gain coefficient adjustment range and high-precision adjustment can be realized.

Description

technical field [0001] The present application relates to the field of radio frequency technology, in particular to a radio frequency receiver with automatic gain control. Background technique [0002] A radio frequency receiver is a device that can receive a radio frequency signal from a long distance and perform anti-modulation to restore it to an electrical information source. At present, radio frequency receivers are widely used in many fields such as vehicle monitoring, remote control and telemetry. RF receivers are mainly divided into superheterodyne receivers, zero-IF receivers and near-zero-IF receivers. [0003] Among them, the zero-IF receiver has the advantages of easy integration, small size and low power consumption, but it is also greatly affected by DC offset, and its noise and linearity are poor. Specifically, when the phase difference between the two local oscillator signals is not accurate to 90°, the two signals overlap, which will cause distortion and a...

AI Technical Summary

Problems solved by technology

[0003] Among them, the zero-IF receiver has the advantages of easy integration, small size and low power consumption, but it is also greatly affected by DC offset, and its noise and linearity are poor

Specifically, when the phase difference between the two local oscillator signals is not accurate to 90°, the two signals overlap, which will cause distortion and a high bit error rate, which in turn will cause baseband I / Q signal mismatch

Similarly, gain mismatch will also cause receiver performance to deteriorate

Images