A Composite Structure Active Feedback Broadband Low Noise Amplifier

Abstract

The invention discloses a compound structure active feedback wideband low noise amplifier, which includes an input amplifier and an active feedback branch; the input amplifier includes a first transistor, a second transistor, a third transistor, a fourth transistor, a fifth transistor, and a first transistor. Six transistors, the first capacitor, the second capacitor, the first resistor, the second resistor, the third resistor and the fourth resistor, using current multiplexing technology to improve the equivalent transconductance, using composite NMOS / PMOS cross-coupling technology to achieve noise elimination, Thereby increasing the gain and reducing the noise figure; the active feedback branch includes a seventh transistor, an eighth transistor, a fifth resistor, a sixth resistor, a seventh resistor, an eighth resistor, a third capacitor, a fourth capacitor, a fifth capacitor and The sixth capacitor satisfies input matching. The circuit structure of the present invention solves the contradiction of mutual restriction of performances such as noise, gain, input matching and bandwidth in the existing fully differential common source low noise amplifier, and has the characteristics of low noise figure and high gain.

Description

technical field [0001] The invention relates to the field of transistor amplification, in particular to a compound structure active feedback broadband low noise amplifier. Background technique [0002] The radio frequency receiver is an important part of the radio frequency integrated circuit, and the low noise amplifier is the first active module in the receiver. In order to accommodate different frequency band applications in a single device, it is necessary to implement an RF receiver supporting multiple standards on a single chip. There are two solutions, one is to integrate several different narrow-band LNAs with switch selection to realize the wide-band receiver, and the other is to use a single wide-band LNA to meet all standards. The second solution can achieve lower cost, area and power consumption, and is the future development trend of broadband receivers. However, there are problems such as noise, gain, input matching and bandwidth that are mutually restricted ...

AI Technical Summary

Problems solved by technology

The invention utilizes the current multiplexing scheme to increase the equivalent transconductance, utilizes the compound NMOS / PMOS transistor to partially eliminate the noise contribution of the input-stage transistor through the cross-coupling technology, and adopts the active feedback technology to solve the noise, gain and input matching in the existing low-noise amplifier Contradictions between performance and bandwidth and other performance constraints, and finally achieve low noise figure and high gain

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