Parallel-resistance feedback differential low-noise amplifier

Abstract

The invention relates to a parallel-resistance feedback differential low-noise amplifier, which comprises a main amplification circuit. The main amplification circuit comprises a first MOS (metal oxide semiconductor) tube, a second MOS tube, a third MOS tube and a fourth MOS tube, a grid end of the first MOS tube is connected with a first differential input end through a first input matching network, the second MOS tube is connected with a second differential input end through a second input matching network, a drain end of the first MOS tube M1 is connected with the grid end of the first MOS tube through a first parallel-resistance feedback branch, and a drain end of the second MOS tube is connected with a grid end of the second MOS tube through a second parallel-resistance feedback branch; the first parallel-resistance feedback branch comprises a first resistor and a first capacitor connected with the first resistor in series; and the second parallel-resistance feedback branch comprises a second resistor and a second capacitor connected with the second resistor in series. The parasitic capacitance of the output end of the amplifier can be reduced, the isolation between the output end and the input end of the amplifier can be improved, good high-frequency characteristics can be achieved, and the circuit stability can be enhanced.

Description

technical field [0001] The present invention relates to a low noise amplifier, especially a resistance parallel feedback differential low noise amplifier, specifically a differential low noise amplifier used in a radio frequency front-end chip of a wireless communication receiver system, which belongs to the category of low noise amplifiers technology field. Background technique [0002] Today, with the rapid development of various wireless communication systems and technologies including mobile communication and wireless local area network, radio frequency integrated circuits (RFIC) have become a research and development hotspot in universities, research institutes and communication-related industries around the world. The development of these wireless communication systems has created a rapidly growing RFIC market. The reason why the radio frequency circuit has received worldwide attention and research is that it is the main bottleneck in the design of the entire wireless...

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Problems solved by technology

However, this method has certain defects, because the resistors R1, R2 and capacitors C1, C2 of the feedback branch will not only introduce additional noise, but also introduce parasitic capacitance at the input and output of the amplifier, which affects the high frequency performance of the amplifier. ; At the same time, the feedback branch directly connected across the input and output of the amplifier reduces the isolation from the output of the amplifier to the input to a certain extent, which is not conducive to preventing the leakage of the large local oscillator signal of the subsequent mixer module to the receiving antenna.

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