X-parameter based GaN device modeling and its application to a high-efficiency PA design

Abstract

X-parameters are supersets of S-parameters and applicable to both linear and nonlinear system modeling. In this paper, a packaged 6 W Gallium Nitride (GaN) RF power transistor is modeled using load-dependent X-parameters by simulations. During the device characterization the load impedance is tuned only up to the 2nd-order harmonic. However, it proves that the model can still accurately approximate the behavior of the transistor under impedance tuning up to the 3rd-order harmonic. The simulation results preliminarily validate the concept of utilizing the X-parameter based modeling technique to decrease the complexity of a harmonic load-pull measurement setup. A high-efficiency 2 GHz power amplifier is also designed for further validation of the concept.