We propose a complete self-defined empirical large-signal model, particularly including the noise characteristics, for the enhancement-mode AlGaAs/InGaAs pHEMTs. This model achieves the excellent fitting of the dc I-V and microwave performance by considering the different contribution of the drain-to-source impedance (R-ds) between dc and rf measurement. In addition, for a full perdition at various biases, all parameters of the model are characterized versus the voltages of gate-to-source and drain-to-source. In consequence, the predictions of the power and IM3 are considerable good. Furthermore, it can also predict the NFmin. and Gamma(opt) points using the P, R, C noise parameters by calculating the noise equations of the equivalent circuit model. This noise figure prediction included model is not always available from the mostly used conventional pHEMT models. (C) 2003 Elsevier Ltd. All rights reserved.