制冷HEMT低噪声放大器偏置电源的研制

Bias Power Supply Design for a Cryogenic HEMT Low Noise Amplifier

高电子迁移率晶体管(HEMT)目前被广泛应用于高灵敏度(低噪声)射电天文接收机中。在低温制冷环境下,其低噪声性能更佳,但对偏置供电系统要求很高,只有在特定的偏置条件下才能得到最佳的低噪声、高增益、高稳定性。本文提供了一套可调试、高稳定、高可靠性、带远程监控功能的可供多级低温制冷HEMT管的偏置电源的设计思路、方法和制作,使在低温制冷状态下的HEMT管能够稳定、安全、可靠地工作在最佳状态。

High electronic mobility transistor （HEMT） is widely used in the high sensitivity （low noise） radio astronomy receivers. Cooling a HEMT - based amplifier to 15K decreases the noise temperature by a factor of ten （and increases gain by about 3dB） compared to room temperature values. But only under the specific bias condition, the HEMT can obtain the optimal low noise, high gain and high stability. A approach to implement a bias power supply having properties of adjustable, super - stable, high reliability with remote monitoring function for multi - stage cryogenic HEMTs is provided in this paper. The correctness and feasibility of the approach have been verified by testing and late application.