Low-noise broadband amplifier with linearity compensation

Abstract

The invention belongs to the design field of radio frequency integrated circuits, which in particular discloses a low-noise broadband amplifier with linearity compensation. The circuit comprises an active feedback unit, a current multiplexing transconductance unit, a direct-current feedback unit and a low-power supply voltage offset unit with the linearity compensation, wherein the direct-current feedback unit is used for stabilizing working points; the active feedback unit realizes broadband input impendence matching; the current multiplexing transconductance unit uses one transistor complementary with a main transconductance unit to serve as the other transconductance unit to improve gain under the condition of the same power consumption; a direct-current feedback loop is used for stabilizing the working points of the circuit; and the low-power supply voltage offset unit with the linearity compensation has the function of linearity compensation under the condition of providing offset to the circuit. According to the low-noise broadband amplifier, the low-noise amplifier with high linearity can be obtained by costing lower power consumption by the CMOS (Complementary Metal-Oxide-Semiconductor Transistor) technology.

Description

technical field [0001] The invention belongs to the technical field of radio frequency integrated circuits, and in particular relates to a low noise amplifier. Background technique [0002] The receiver front end of a communication system usually includes a low noise amplifier (LNA), a mixer (Mixer), a variable gain amplifier (VGA) and some filters. As the first stage of the active circuit in the receiver, the LNA needs to amplify the input signal, reduce the noise of the whole system, and at the same time complete the impedance matching with the input terminal, and its performance often sets the limit for the performance of the whole receiver. [0003] Traditional narrowband receivers deal with signals with a bandwidth of only tens of kilohertz to several megahertz, and out-of-band images, spurs and noise can be well filtered out by filters. However, the current development of multi-mode communication has proposed different system requirements. In a system that needs to p...

AI Technical Summary

Problems solved by technology

In this example, the active feedback unit 110 imposes a voltage drop between the input and output nodes of the amplifier that is greater than the gate-source voltage of transistor M2, making the circuit difficult to apply to low supply voltage applications

Moreover, the active feedback adopted by this circuit belongs to nonlinear feedback. Although the use of the feedback resistor 102 can partially linearize the circuit, further improvement of the linearity requires the help of other methods.

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