Temperature-dependent noise parameters and modeling of InP/InAlAs/InGaAs HEMTs

In this paper, we present the small-signal and noise modeling of InP/ln/sub 0.8/Ga/sub 0.2/As HEMTs at cryogenic temperatures. The effect of various physical mechanisms influencing the small-signal parameters, especially the RF transconductance and RF output resistance and their temperature dependence are discussed in detail. Accurate on-wafer noise parameter measurements are carried out on InP HEMTs from 300 K to 18 K and the variation of the equivalent noise temperatures of drain and source (T/sub d/ and T/sub g/) are modeled against temperature. A cryogenic LNA in the Ka-band with a noise temperature of 10 K has been demonstrated.