Nonlinear-dispersive GaAs FET drain-current model for harmonic balance simulation

Popular GaAs FET large-signal drain conduction current models depend only on instantaneous terminal voltages, and ignore important phenomena that result in low frequency dispersion. To be valid at microwave frequencies, both the DC and time-varying components of current must be accurately modelled. This paper proposes a GaAs FET drain current model, which includes rate-dependent body and thermal effects, and therefore has the capability to accurately predict both the DC and time-varying components of drain current. Further, this model is particularly suited to harmonic balance simulation of microwave circuits