High-frequency low-noise amplifier circuit structure

Abstract

The invention discloses a high-frequency low-noise amplifier circuit structure. The circuit structure comprises a signal input end, a radio frequency amplification circuit, a load and a signal outputend. The radio frequency amplifying circuit comprises a first-stage amplifying circuit and a second-stage amplifying circuit which are cascaded, and the radio frequency amplifying circuit is of a self-biased structure. The structure has the advantages of simple structure and good noise performance.

Description

technical field [0001] The invention relates to the field of amplifiers, in particular to a circuit structure of a high-frequency low-noise amplifier. Background technique [0002] As the pre-radio frequency signal amplifier of the radio receiver, the low noise amplifier needs to amplify the radio frequency signal under the premise of generating noise as low as possible, so as to reduce the influence of the noise generated by the subsequent modules on the signal. [0003] Such as figure 1 As shown, the traditional low-noise amplifier used in satellite TV receivers usually consists of two cascaded FET amplifiers to achieve extremely low noise figure, high signal gain and good stability. Its circuit structure mainly includes a primary amplifier circuit 1', a secondary amplifier circuit 2', a first bias circuit 3' and a second bias circuit 4', the primary amplifier circuit 1' includes a first field effect transistor MN1', The secondary amplifying circuit 2' includes a second ...

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Problems solved by technology

However, there are the following problems: the gain of each stage of the amplifier circuit is low, and there are many components in the bias circuit, and the overall circuit occupies a large area of ​​the PCB board, that is, the layout area of ​​the overall circuit is large.

[0006] Based on the shortcomings of traditional low-noise amplifiers, the Chinese patent "CN204272090U" proposes a high-frequency interface circuit. In this high-frequency interface circuit, an improved low-noise amplifier circuit structure is provided to multiplex the load of the low-noise amplifier A' In the subsequent RF circuit RF', such as figure 2 As shown, the load of the low-noise amplifier A' is the primary coil of the balun T' at the input terminal of the RF circuit RF' of the subsequent stage; the first end of the primary coil of the balun T' is connected to the output terminal of the low-noise amplifier A', and the barun The second end of the primary coil of Lun T' is connected to the first end of the DC bias voltage signal Bias' and the DC blocking capacitor Cp', and the second end of the DC blocking capacitor Cp' is grounded; the existing high-frequency interface circuit can be improved The number of components on the circuit board, the PCB area occupied by the circuit, and the manufacturing cost of the circuit are considered, but the low-noise amplifier A' has only one stage of amplification, and the gain is not large enough to make the overall noise figure of the circuit sufficiently small, resulting in poor noise performance.

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