The Effect of low temperature on DC and RF characteristics of GaAs pHEMT

In this paper, the characteristics of domestic GaAs pHEMT device in cryogenic temperature region are measured and analyzed. From 250K to 77K, the DC performance is improved a lot, the saturation current increases by 20%, and the pinch-off voltage increases slightly. Besides, the RF performance is improved significantly. The gate resistance decreases to 40% as the temperature decreases, the characteristic frequency increases from about 32GHz to over 42GHz, and the highest oscillation frequency increases from about 100GHz to over 120GHz.