Temperature-dependent small-signal and noise parameter measurements and modeling on InPHEMTs

In this paper, we present detailed on-wafer S-parameter and noise parameter measurements and modeling of InP/InAlAs/InGaAs high electron mobility transistors (0.1-mum gate length) at cryogenic temperatures, Various physical effects influencing small-signal parameters, especially the radio-frequency (RF) transconductance and RF output resistance and their temperature dependence, are discussed in detail. Accurate on-wafer noise parameter measurements are carried out from 300 to 18 K, and the variation of the equivalent noise temperatures of drain and source (T-d and T-g) are modeled against temperature. Based on these models, a cryogenic low-noise amplifier in the Ka-band is developed with a record-low noise temperature of 10 K.