Scalable large-signal model for large RF power MESFETs

Abstract

Novel extraction and scaling procedures were developed for a commercially-available large-signal model which accurately predicted the performance of large RF power MESFETs with total gate widths on the order of cm. Most model parameters were found to be either independent of or linearly dependent on the total gate width. The only nonlinear scaling factors were attributed to higher thermal resistances of large MESFETs caused by nonuniform self heating. Modeled output waveforms and harmonic powers under class AB and B conditions were in excellent agreement with measured data.