High-linearity low-noise amplifier

Abstract

The invention provides a high-linearity low-noise amplifier of the front end of an ultrahigh-frequency RFID (radio frequency identification) receiver. The amplifier detects two common levels from two differential output ends of a full-differential amplifier through a common-feedback circuit, bias current of the amplifier is adjusted validly and feedback voltage is outputted to a grid of a tail current source, and accordingly, overdrive voltage of the tail current source is increased, input current is increased and linearity is improved. Meanwhile, the problem of non-linear distortion caused by instability of the output common levels is solved. In addition, a coupling capacitor is crossed interstagely to increase power grain, and noise figure is reduced to improve noise performance. The high-linearity low-noise amplifier has the advantages of low noise figure, low power consumption, and high linearity, and solves the problem of carrier leak in ultrahigh-frequency RFID receivers and zero intermediate frequency receivers, and linearity of the low-noise amplifier is improved, so that weak available signals can be amplified linearly and distortionlessly in the process of receiving block signals.

Description

technical field [0001] The invention belongs to the field of radio frequency integrated circuit design, in particular to a high-linearity low-noise amplifier. Background technique [0002] In recent years, wireless communication technology has developed rapidly and plays an increasingly important role in social life. The development of wireless communication puts forward higher requirements on the front-end circuit of the transceiver. [0003] Low Noise Amplifier LNA (Low Noise Amplifier) ​​is the first stage of the receiver front end, and its performance directly affects the performance of the entire receiver system. The overall noise figure of the system depends on the noise performance of the first stage LNA. In addition to the overall noise of the system, whether it is transmitting or receiving data, the antenna will continue to transmit a large carrier signal. The carrier signal leaks into the front end of the receiver through a circulator or a directional coupler, and...

AI Technical Summary

Problems solved by technology

And because most of the communication systems receive and transmit signals at the same carrier frequency, it is impossible to filter out the leaked carrier signal through a radio frequency band-pass filter at the front end of the receiver, resulting in desensitization and blocking at the front end of the receiver, which seriously affects the receiving link. dynamic range of

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