SIMULATION OF HEMT DC DRAIN CURRENT AND 1 TO 50 GHZ S-PARAMETERS AS AFUNCTION OF GATE BIAS

The usefulness over an extended range of a HEMT model previously valid ated for 1 to 25 GHz s-parameter model is shown. Experimental and simu lation results for the dc drain current and 1-50 GHz s-parameters of a pseudomorphic 0.32-pm-gate AlGaAs/InGaAs/GaAs HEMT are presented. The model predicts the device's dc current and s-parameters as a function of the applied gate bias with good accuracy. The core of the model is directly dependent on the HEMT wafer structure and the physical gate length. As part of the modeling procedure, a value of (1.77 +/- 0.07) x 10(5) . m s-1 is found, confirming the results of other research, fo r the electron velocity in undoped pseudomorphic In0.15Ga0.85As under almost-equal-to 0.3 mum gates.