A Nonlinear GaAs FET Model for Use in the Design of Output Circuits for Power Amplifiers

A nonlinear equivalent circuit model for the GaAs FET has been developed based upon the small-signal device model and separate current measurements, including drain-gate avalanche current data. The harmonic balance technique is used to develop the FET rf load-pull characteristics in an amplifier configuration under large signal operation. Computed and experimental load-pull results show good agreement.