Effect of spatial distribution of dissipated power on modeling of SMR BAW resonators at high power levels

The modeling of bulk acoustic wave resonators at elevated power levels has been improved by taking the spatial distribution of the dominating loss mechanisms into account. The spatial distribution of the dissipated power enables more accurate modeling of the temperature increase caused by the applied power. Thus, it is also possible to more accurately model the frequency shifts of the resonators' impedance curves resulting from the temperature increase caused by the applied power. Simulation and measurement results for the temperatures and impedances of the resonators with different layerstacks at high power loads are presented. The simulation and measurement results are in good agreement, confirming the presented modeling approach. Furthermore, the de-embedding procedure used to obtain vectorial scattering parameters of the resonators during high power loads, the according measurement setup, and the procedure for measuring absolute temperatures by infrared thermography are discussed.