Broadband fully-differential low-noise amplifier

Abstract

The invention relates to a broadband fully-differential low-noise amplifier. The low-noise amplifier is characterized by including two levels consisting of an input matching level circuit and a noiseneutralizing level circuit; the input end of the input matching level circuit receives signals (IN1 / IN2) of a signal input end, and generates two channels of signals which are opposite in phase; the two channels of signals are respectively output to a next level of noise neutralizing level circuit by a high-pass filter consisting of capacitors and resistors; the noise neutralizing level circuit isprovided with three input ends and three output ends on both sides, wherein one input end is connected with the output end of the input matching level circuit, and the two input ends receive signals(IN1 / IN2) of a differential signal input end and then output two channels of differential signals (OUT1 / OUT2).

Description

technical field [0001] The invention belongs to the technical field of radio frequency integrated circuits, and in particular relates to a 500M-1.5GHz broadband fully differential low-noise amplifier. Background technique [0002] With the development of wireless communication, the role of radio frequency receiving technology in military and civilian fields is becoming more and more important. Broadband communication system is the development trend of today's wireless communication technology, and it is also a hot spot of research at home and abroad. RF Low Noise Amplifier (LNA) is a key component in electronic countermeasures, broadband communications and broadband instruments. The signal of the LNA comes directly from the antenna. In order to achieve maximum power transmission, impedance matching is required between the LNA input and the antenna. In addition to amplifying the weak signal received from the antenna to increase the overall gain of the circuit in the radio f...

AI Technical Summary

Problems solved by technology

The common gate amplifier uses the transconductance of the input tube to achieve broadband matching. The noise figure has little relationship with the operating frequency and bandwidth and is relatively flat. The circuit has excellent reverse isolation performance and high linearity, but the noise figure is high.

Another disadvantage of common-gate amplifiers is that in low-frequency applications, the external inductance L is very large, and large inductors cannot accommodate high-frequency signals

Resistors connected in parallel to feedback the common source amplifier reduce the quality factor at the input end to achieve bandwidth expansion and gain flattening, but the resistance itself will introduce noise, which will deteriorate the noise characteristics at the input end

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