Bias circuit used in Ku waveband internally-matched field effect transistor

Abstract

The invention discloses a bias circuit used in a Ku waveband internally-matched field effect transistor. The bias circuit is characterized in that the bias circuit consists of a grid bias circuit of amicrostrip stub structure, the Ku waveband internally-matched field effect transistor and a drain bias circuit of a dual-segment microstrip stub structure, wherein the grid bias circuit is connectedwith the grid of the Ku waveband internally-matched field effect transistor, while the drain bias circuit is connected with the drain of the Ku waveband internally-matched field effect transistor. Thebias circuit can effectively restrain low-frequency oscillation which frequently occurs inside a Ku waveband microwave power amplifier, thereby increasing the stability of the amplifier and broadening the bandwidth of the bias circuit at very low insertion loss. Therefore, the bias circuit can be used in various Ku waveband microwave power amplifiers based on internally-matched field effect transistors.

Description

technical field [0001] The invention relates to the technical field of microwave power amplifiers, in particular to a bias circuit for matching field effect transistors in the Ku band. Background technique [0002] In radar transmitter systems, electronic countermeasures, intelligent missiles, and various communication and navigation electronic systems, microwave power amplifiers using Ku-band matched field-effect transistors as active devices are widely used. [0003] Since the DC power supply and microwave signal input and output of most internally matched field effect transistors share pins, the bias circuit and the microwave link will interact with each other, which may cause low-frequency oscillation of the microwave power amplifier, microwave signal leakage through the bias circuit, and power loss. Amplifier gain and phase variations create distortion. [0004] For the internally matched microwave power tubes in the lower frequency band, the DC bias is generally provi...

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Problems solved by technology

[0006] However, the broadband performance of this structure is poor, and it will introduce relatively large insertion loss for applications with a wide operating frequency band

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