GaN Device Modeling with X-Parameters

Arbitrary-load-dependent X-parameters, automatically measured with a load-tuner working with an NVNA, are used to characterize and model a packaged 10W GaN transistor. A full nonlinear two-port functional block model for PA and other circuit design is immediately available for nonlinear simulation. It is demonstrated that the model predicts well the independent effects of harmonic load tuning without having to independently control harmonic loads during characterization. The nonlinear model can be used effectively to obtain optimal fundamental and harmonic impedances for device operation, as well as predict, accurately, other nonlinear FOMs including PAE and harmonic distortion. Source-pull is shown to be unnecessary except for efficient power transfer, yet the model is fully capable of predicting correct device response when embedded in any source and load impedance at the fundamental and harmonics.