X-parameters and efficient physical device simulation of mm-wave power transistors with harmonic loading

We report on an alternative application of X-parameters to improve the efficiency of a general TCAD physical device simulator when simulating the response of a RF power transistor to different load impedance harmonic terminations. In particular, we combine large-signal circuit-device simulations with the predictive capability of X-parameters in order to avoid very time-consuming multi-harmonic simulations. The success of this approach, that is applicable to any physical device simulator, is validated by comparing the current-voltage waveforms of a standard GaN HEMT simulated through multi-harmonic termination device simulations with the ones predicted through X-parameters extracted from single-harmonic termination device simulations. The proposed method greatly improves the speed of the physical simulation of nonlinear device operations with different harmonic loading, the speed of the TCAD X-Parameter extraction, and also reduces convergence issues.