A high reliability low noise amplifier

Abstract

The invention relates to a high-reliability low-noise amplifier, comprising a high-power input protection module and an amplifier module. The amplifier module includes an amplifier circuit, an input bias circuit and a decoupling capacitor. The first end of the input bias circuit is connected to the amplifier circuit. The input end of the first stage amplifier, the second end is grounded through a decoupling capacitor, and the high-power input protection module includes: a matching circuit for input impedance matching and DC isolation of the low-noise amplifier; a DC current detector for detecting the first stage The DC current at the input end of the amplifier is converted into a detection voltage for external output; a level conversion circuit is used to output a control signal after the detection voltage exceeds a pre-configured threshold; a limiter circuit is connected to the matching circuit at one end and grounded at the other end, and The control terminal is connected with the output terminal of the level conversion circuit, and is turned on after receiving the control signal to protect the amplifying circuit. Compared with the prior art, the present invention has little influence on other performances of the amplifier while improving the reliability of the amplifier.

Description

technical field [0001] The present invention relates to the technical field of radio frequency front-ends of electronic equipment, in particular to a high-reliability low-noise amplifier. Background technique [0002] The Low Noise Amplifier (LNA) is located at the front end of the receiver of the communication system, and its main function is to amplify the weak signal with noise received by the antenna, such as figure 1 As shown, it is an important circuit module in communication electronic equipment. In practical applications, the working environment of communication equipment is uncertain, especially when it is used in high-power scenarios such as communication base stations, there may be strong electromagnetic interference in the space received by the receiving antenna, and high-power signals appear at the input of the low-noise amplifier. damage or destroy it. In addition, the radio frequency transmitter radiates high power, and there will be signal reflection at the...

AI Technical Summary

Problems solved by technology

In the millimeter wave frequency band, it is difficult to realize the detection circuit, and at the same time, the parasitic parameters of it and the switching tube limiter circuit will have a great impact on the input matching, noise figure and gain performance of the low noise amplifier.

In addition, if a depletion-mode transistor design is adopted, since the threshold voltage is negative, the control voltage of the switching tube limiting circuit needs to be specially designed, and generally requires an additional bias voltage. supply voltage, increasing the cost

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