High-reliability low-noise amplifier

Abstract

The invention relates to a high-reliability low-noise amplifier, which comprises a high-power input protection module and an amplifier module, wherein the amplifier module comprises an amplifying circuit, an input bias circuit and a decoupling capacitor; the first end of the input bias circuit is connected to the input end of a first-stage amplifier of the amplifying circuit; the second end of the input bias circuit is grounded through the decoupling capacitor; the high-power input protection module comprises a matching circuit used for input impedance matching of the low-noise amplifier and DC isolation, a direct current detector used for detecting the direct current of the input end of the first-stage amplifier and converting the direct current into detection voltage and outputting the detection voltage, a level conversion circuit used for outputting a control signal after the detection voltage exceeds a pre-configured threshold value, and an amplitude limiting circuit one end of which is connected with the matching circuit, the other end of which is grounded, the control end of which is connected with the output end of the level conversion circuit, and which is turned on to protect the amplifying circuit after receiving the control signal. Compared with the prior art, the reliability of the amplifier is improved, and meanwhile, the influence on other performances of the amplifier is small.

Description

technical field [0001] The 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 communication system receiver, 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 a high-power signal appears at the input end of the low-noise amplifier. damage or destroy it. In addition, when the RF transmitter radiates high power, there will be signal reflection at the antenna due to misma...

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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