Influence of Dissipated Power Distribution on BAW Resonators
Tag A, Karolewski D, Bader B, Pitschi M, Weigel R, Hagelauer AM (2014)
Publication Type: Conference contribution
Publication year: 2014
Publisher: IEEE
Pages Range: 2627-2630
Event location: Chicago, Illinois
Abstract
Background, Motivation and Objective: Bulk Acoustic Wave (BAW) filters and Duplexers are often used at high power levels at which the temperature of the device increases due to power dissipation (self-heating) resulting in turn in significant frequency shifts of the transfer function of the device. This behavior needs to be modeled accurately to be able to design devices working appropriately at these power levels. Statement of Contribution/Methods: Simulations with coupled electromagnetic (EM) acoustic thermal 3D finite element methods (FEM) require tremendously high calculation times. The solutions presented in the literature are based on a measured TCF and dissipated power calculated from S-parameters. That means neither the distribution of temperature nor the distribution of the dissipated power are considered. In our previously work, we have shown that the modeling of the frequency shifts caused by the self-heating behavior can be improved by taking the spatial temperature distribution into account. In this work, it will be shown for the first time that the spatial distribution of dissipated power considerably influence the temperature level and temperature distribution. Therefore, it has to be taken into account in order precisely model the BAW self-heating behavior. Results, Discussion and Conclusions: The acoustic was modeled in one dimension allowing efficient calculation times. EM has been modeled with a 3D FEM simulation program. From the obtained strain distribution along the different layers of the resonator (an example is shown in Fig. 1) the spatial distribution of viscous losses along the different layers was calculated and transferred to the thermal 3D simulation. The remaining main losses (eddy currents, redistribution currents, resistivity losses, and dielectric losses) were applied to the electrodes and piezoelectric layer. The result of the thermal simulation was the spatial temperature distribution over the device geometry. This temperature distribution was used to modify the geometry of the resonator and the materials for the EM and acoustic simulations. Finally, the acoustic and EM simulations were repeated with all the modifications providing the behavior of the resonator at high power level. By the extension of the modeling approach remarkable improvements (some tens of percents) in the modeling of the temperature level and the resonator transfer function frequency shifts have been achieved.
Authors with CRIS profile
Andreas Tag
Lehrstuhl für Technische Elektronik
Robert Weigel
Lehrstuhl für Technische Elektronik
Amelie Marietta Hagelauer
Lehrstuhl für Technische Elektronik
How to cite
APA:
Tag, A., Karolewski, D., Bader, B., Pitschi, M., Weigel, R., & Hagelauer, A.M. (2014). Influence of Dissipated Power Distribution on BAW Resonators. In Proceedings of the 2014 IEEE International Ultrasonics Symposium (pp. 2627-2630). Chicago, Illinois, US: IEEE.
MLA:
Tag, Andreas, et al. "Influence of Dissipated Power Distribution on BAW Resonators." Proceedings of the 2014 IEEE International Ultrasonics Symposium, Chicago, Illinois IEEE, 2014. 2627-2630.
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