Modeling nonlinear behavior of RF Bulk Acoustic Wave resonators

In this work, the Poly-Harmonic Distortion (PHD) model has been used to characterize the nonlinearities of Bulk Acoustic Wave (BAW) solidly mounted resonators (SMR). The new approach of using X-parameters for characterization and simulation of nonlinearities is described. The amplitude and phase of the fundamental mode and its harmonics up to third order have been measured and simulated by using the X-parameter framework. The simulation and measurement results for phase and amplitude of X-parameters describing the relations between incident and reflected harmonics of the same as well as different orders are shown. The X-parameter measurements of BAW components up to third order harmonics have been carried out with a nonlinear vector network analyzer (NVNA). These measurements under large-signal operating conditions were used to determine the nonlinear material constants responsible for the nonlinearity in BAW resonators.