Analysis of intrinsic small signal parameters in HEMTs

A charge control model was developed which is based on a single analytical function that describes the dependence of the three charges in HEMTs on gate voltage. These charges include: 2DEG, AlGaAs free electrons and neutralized donors. Closed form expressions for the intrinsic small signal model parameters in linear and saturation regions were derived. The contributions of both the AlGaAs and neutralized donor charges, which were commonly ignored in early models, were studied at different gate and drain bias voltages.