Implementation of a Behavioral Model of SSPAs taking into account mismatches for efficient System Simulation of Modern AESA

This paper presents a behavioral modeling approach for solid state power amplifiers (SSPAs) used in Radar applications. This model takes into account strong output loading impedance mismatch, with a VSWR (voltage standing wave ratio) equal to two. The proposed behavioral model, based on non-linear Scattering functions, is extracted from simple CW measurements or Harmonic Balance (HB) simulations. This model has been implemented in a general purpose system simulation environment, Scilab/Scicos, thanks to a toolbox dedicated to solving implicit problems. In this paper, the proposed behavioral model is extracted from HB simulation results of an S-band 20 Watt power amplifier. Our macromodeling methodology is validated by comparisons of circuit and behavioral model simulations under pulse signal excitation in the case of loading impedance mismatch. This work has the financial support of the DGA (French defence and security agency).