Expanding the power-handling capabilities of harmonic-balance analysis by a parametric formulation of the MESFET model

A novel method for improving the convergence properties of the Newton iteration in the analysis of hardly driven nonlinear microwave FET circuits by the harmonic-balance technique is presented. The active device is described by a set of parametric equations allowing the exponential difference of the Schottky-barrier current on the applied voltage to be exactly implemented by means of well-behaved functions. As a result, the power-handling capabilities of the undamped Newton iteration become comparable to those of norm-reducing Newton methods based on conventional models. Furthermore, coupling parametric modelling with norm reduction results in an extremely robust analysis approach.