A CMOS Broadband Low Noise Amplifier with Adjustable Gain

Abstract

The invention discloses a gain-adjustable CMOS (Complementary Metal-Oxide-Semiconductor Transistor) broadband low-noise amplifier. The gain-adjustable CMOS broadband low-noise amplifier comprises a main gain grade circuit, an input impedance matching circuit, a gain control grade circuit and a feedback capacitance unit. According to the gain-adjustable CMOS broadband low-noise amplifier, programmable voltage is generated through controlling conduction of a tail current source; the programmable voltage is applied to a grid electrode of a common-gate tube of the main gain grade circuit, and transconductance of the common-gate tube is changed, so that grid source voltage of a common-source tube is changed, and the transconductance of the common-source tube is changed, furthermore, a transconductance sum of the common-gate and common-source tubes of an input grade is changed; finally, input matching is changed to generate different amplification gains; meanwhile, a feedback capacitance which is output to input is introduced to compensate the input matching when regulating voltage is different; accurate gain stepping of broadband matching and low-noise amplifiers can be realized through reasonably planning the programmable voltage and the feedback capacitance.

Description

technical field [0001] The invention belongs to the technical field of CMOS integrated circuits, and in particular relates to a gain-adjustable CMOS broadband low-noise amplifier. Background technique [0002] Wireless communication is one of the fastest growing technologies today. In the past ten years, with the rapid development of personal communication systems, digital TV, and broadcasting, people's research on RF front-end transceivers has entered a white-hot state. Due to the continuous increase in the amount of communication data, multi-mode, multi-frequency and broadband communication is gradually becoming a trend. Multi-mode multi-frequency receivers need to be compatible with multiple frequency points and have a wide frequency coverage. This puts forward higher requirements for the low-noise amplifier of the ultra-wideband receiver, requiring noise matching and signal low-noise amplification at multi-mode and multi-frequency points. At the same time, with the de...

AI Technical Summary

Problems solved by technology

[0007] Aiming at the above-mentioned technical defects existing in the prior art, the present invention provides a CMOS broadband low-noise amplifier with adjustable gain. The circuit structure is composed of MOS transistors, capacitors and resistors. There is no integrated inductor, which greatly reduces the chip area, and can also ensure a certain noise figure in the case of adjustable gain

Images