Probe based simulation technique for modeling saturated power amplifiers

This paper describes a probe based analysis technique for the simulation of saturated power amplifiers. The method is in-situ, compatible with linear & nonlinear simulation and accounts for the impact of network symmetry on the performance of the circuit. The load impedance is determined for every transistor cell in the circuit enabling the calculation of output power, network loss and drive margin for the entire amplifier. The technique is applied to a binary manifold typical of high frequency amplifiers, as well as a single stage GaN x-band high power amplifier design. Measured results for the GaN power amplifier at 9.4GHz under continuous wave conditions demonstrate 41.6W output power with associated gain and power added efficiency of 9.5dB and 44% respectively.