L Band Cryogenic Low Noise Amplifier

摘要

The physical characteristics of high electron mobility transistors (HEMT) is mentioned first, and then a cryogenic low noise amplifier (LNA) is reported, the designed LNA which takes good advantage of the excellent performance of cryogenic HEMT has extremely low noise figure and good VSWR because of the use of series feedback technology. At temperature of 77K the measurement result indicates that over the 1.1GHz~1.35GHz frequency band the noise figure is around 0.3dB, the input reflection is lower than -20dB, and the gain is above 17dB. The performance of the LNA is consistent with the requirement.