A complete and accurate surface-potential based large-signal model for compound semiconductor HEMTs

A complete and accurate surface potential based large-signal model for compound semiconductor HEMTs is presented. A surface potential equation resembling the one used in conventional MOSFET models is achieved. The analytic solutions from the traditional surface potential theory that developed in MOSFET models are inherited. For core model derivation, a novel method is used to realize a direct application of the standard surface potential model of MOSFETs for HEMT modeling, without breaking the mathematic structure. The high-order derivatives of I-V/C-V remain continuous, making the model suitable for RF large-signal applications. Furthermore, the self-heating effects and the transconductance dispersion are also modelled. The model has been verified through comparison with measured DC IV, Gummel symmetry test, CV, minimum noise figure, small-signal S-parameters up to 66 GHz and single-tone input power sweep at 29 GHz for a 4 x 75 mu m x 0.1 mu m InGaAs/GaAs power pHEMT, fabricated at a commercial foundry.