Low-noise amplifier

Abstract

The invention discloses a low-noise amplifier. The low-noise amplifier comprises an input impedance matching circuit, an amplification circuit and an output impedance matching circuit. The input impedance matching circuit comprises an active inductive circuit for matching input impedance under different frequencies. The active inductive circuit comprises a first NMOS transistor, a second NMOS transistor, a third NMOS transistor and a fourth NMOS transistor. A source electrode of the first NMOS transistor is connected with a third current source, and a drain electrode of the first NMOS transistor is connected with a voltage source; a drain electrode of the second NMOS transistor is connected with a second current source and a grid electrode of the first NMOS transistor; a drain electrode of the third NMOS transistor is connected with a source electrode of the second NMOS transistor, a grid electrode of the third NMOS transistor is connected with the source electrode of the first NMOS transistor, and a source electrode of the third NMOS transistor is grounded; a drain electrode of the fourth NMOS transistor is connected with a grid electrode of the second NMOS transistor and a first current source, a grid electrode of the fourth NMOS transistor is connected with the source electrode of the third NMOS transistor, and a drain electrode of the fourth NMOS transistor is grounded; the amplification circuit is connected with the active inductive circuit and the output impedance matching circuit. According to the low-noise amplifier, signals can be amplified under different frequencies.

Description

technical field [0001] The invention relates to the field of integrated circuits, in particular to a low noise amplifier. Background technique [0002] The low-noise amplifier is one of the important modules in the radio frequency transceiver. It is mainly used in the communication system to amplify the signal received from the antenna, so as to facilitate the processing of the receiver circuit in the subsequent stage. [0003] Since the signal from the antenna is generally very weak, the low noise amplifier is generally located very close to the antenna to reduce signal loss. It is precisely because the noise amplifier is located at the first stage of the entire receiver close to the antenna, its characteristics directly affect the quality of the signal received by the entire receiver. In order to ensure that the signal received by the antenna can be correctly recovered in the final stage of the receiver, a good LNA needs to amplify the signal while generating the lowest p...

AI Technical Summary

Problems solved by technology

[0005] Generally speaking, the low-noise amplifier inductor used for input matching is composed of passive components, which not only requires the support of the inductor process in the integrated circuit manufacturing process, that is, the thickness of the top layer and the sub-top layer metal is very large, but also because the inductor occupies a lot of layout resources make the cost of the entire LNA higher

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