场效应器件低温特性与低噪声放大器

高温超导滤波器与低噪声放大器(LNA)组成的射频接收机前端设备具有高选择性、高灵敏度和极低的噪声,因而展现出广阔的应用前景.本文研究了场效应器件的低温物理特性和电学参数,研制了一种适用于高温超导微波接收系统的低温低噪声放大器,在60K工作温度下,具有很好的噪声特性.包括高电子迁移率场效应晶体管在内的元件参数均在60K温度下进行了实际测量.放大器的各项指标与设计值吻合,工作频段为800MHz～850MHz,增益大于18dB,输入输出驻波比小于1.2,噪声系数小于0.22dB.

CRYOGENIC CHARACTERISTICS OF HIGH ELECTRON MOBILITY TRANSISTOR AND LOW NOISE AMPLIFIERS

High Temperature Superconductor (HTS) receiver front-end subsystem for mobile telecommunications is one application in microwave circuit. The system aims to the possibility of high selectivity and high sensitivity and low noise figure. HTS receiver front end contains HTS filters and cryogenic low noise amplifiers (CLNA). Research of Cryogenic Physical and Electrical characteristics of High Electron Mobility transistor (HEMT) is necessary for design CLNA. In this paper, the physics and electronic characteristic of HEMT transistor in cryogenic temperature, and the performance of cryogenic low noise amplifier (LNA) which used for high temperature superconducting receiver front end have been reported. The cryogenic LNA has extremely low noise figure in 60K working temperature. The electronic parameters of circuit components were measured in 60K temperature including the HEMT Transistor. The measurement result of the LNA matches the simulation result of the design. The working frequency band of the LNA is from 800MHz to 850MHz, Gain is above 18dB, noise figure is lower than 0.22dB, input and output standing wave ratio are less than 1.2.