Nonlinear simulation and modeling of nonlinear microwave transistors

Two methods for simulating microwave and millimeter-wave nonlinear circuits are presented. The steps required for large signal microwave MESFET modeling are described. The time-domain analysis method is briefly presented; its important advantage is that it allows transient states study. The second method based on the harmonic balance technique makes it possible to quickly obtain the steady-state regime of a nonlinear microwave circuit. Procedures required in MESFET modeling also described. Small signal measurements are used to obtain the linear model and large signal measurements are used to obtain the intrinsic nonlinear parameters of the transistor, which makes it possible to deduce the nonlinear model. Simulation and modeling results are presented.