The effect of the gate Schottky diode on pHEMT power amplifier performance

This paper presents for the first time a practical systematic investigation into the effects of gate Schottky parameter values on large-signal amplifier performance. The use of a new Schottky diode model for a packaged pHEMT device shows significant improvements over the vendor supplied model when used in the non-linear characterisation of a class A power amplifier. Special emphasis is placed on the effect these values exhibit on the ability of the large-signal model to predict measured power amplifier characteristics including gain, output power, efficiency, linearity, ACPR and non-linear spectral regrowth.