A novel non-linear GaAs fet model for intermodulation analysis in general purpose harmonic-balance simulators

The ability of most widely used non-linear MESFET models to predict detailed device's characteristics, as S parameter bias dependence and intermodulation (IMD) is reviewed. Their almost general lack of capacity to reproduce the higher order derivatives of the I(v) and Q(v) curves, makes them completely useless to simulate small signal harmonic or IMD distortions. Since the usual proposed alternative is based on truncated Taylor Series, which is not applicable to DC bias calculations or strong non-linear operation, there is not a single model that can be selected for all these kinds of problems. The aim of this work is to present a novel GaAs FET model that integrates these two domains of microwave non-linear simulation.