Cryogenic low-noise InP HEMTs: A source-drain distance study

The scaling effect of the source-drain distance was investigated in order to improve the performance of low-noise InP HEMTs at cryogenic temperatures 4–15 K. The highest dc transconductance at an operating temperature of 4.8 K and low bias power was achieved at a source-drain distance of 1.4 µm. The extracted HEMT minimum noise temperature was 0.9 K at 5.8 GHz for a 3-stage 4–8 GHz hybrid low-noise amplifier at 10 K.