Cryogenic microwave performance of 0.5- mu m InGaAs MESFET's

Microwave and DC properties of 0.5- mu m InGaAs MESFETs were measured at 300 and 125 K. The authors have measured approximately 30% increases in RF g/sub m mod ext/ and f/sub T/ when cooling from 300 to 125 K. The authors also observe a 0.06-V increase in gate built-in voltage at 125 K that results in smaller gate leakage currents. The improved gate characteristic at 125 K leads to better RF properties at higher gate bias.<
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