Low-noise amplifier adopting single-ended input and differential output

Abstract

The invention provides a low-noise amplifier adopting single-ended input and differential output. The low-noise amplifier comprises a first circuit, a second circuit, a tail current source tube circuit, a compensation circuit and a biasing circuit. The first circuit comprises at least one first field effect transistor. The input end of the first circuit is connected to the output end of an input matching network, and the output end of the first circuit is connected to an output matching network. The second circuit comprises at least one second field effect transistor, and is connected with the first circuit to form a differential pair structure. The output of the second circuit is connected with the output matching network. The tail current source tube circuit is connected with a common connection point of the first and second circuits. The compensation circuit is bridged between the first and second circuits, and is used for compensating an output signal of the second circuit to match the output signals of the first and second circuits. The biasing circuit is connected with the first and second circuits, and is used for providing DC bias. The low-noise amplifier has the advantages that: 1) the output signals are symmetrically differential; and 2) the overall gain of the amplifier is relative constant at various process voltage temperatures.

Description

technical field [0001] The invention relates to the field of integrated circuits, in particular to a low-noise amplifier with single-end input and differential output. Background technique [0002] The low-noise amplifier is usually the first stage of the receiving system, and it needs to provide enough gain to reduce the noise contribution equivalent to the input of the receiver from the subsequent module. In addition, it must also have a very low noise figure, because it has The noise figure will be reflected 1:1 to the overall noise figure of the receiver. [0003] In an analog integrated circuit, each gain block stage is a voltage amplifier, so it is desirable for each amplifier to have as high an input impedance as possible and as low an output impedance as possible. However, since the low-noise amplifier is the first stage of the chip, it needs to be connected to an off-chip surface acoustic wave filter (SAW filter) or other devices. Usually these devices have standar...

AI Technical Summary

Problems solved by technology

However, limited by the integrated circuit technology, the inductance value of the planar inductor is difficult to increase, so it is difficult for the RF signal to achieve complete differential symmetry after being amplified by the second-stage common-source and common-gate amplifier circuit.

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