VTT Technical Research Centre of Finland, Microsystems and Nanoelectronics, Espoo, Finland.
IEEE Trans Ultrason Ferroelectr Freq Control. 2010 Nov;57(11):2537-49. doi: 10.1109/TUFFC.2010.1720.
A 2-D model is developed for calculating lateral acoustical coupling between adjacent thin film BAW resonators forming an electrical N-port. The model is based on solution and superposition of lateral eigenmodes and eigenfrequencies in a structure consisting of adjacent regions with known plate wave dispersion properties. Mechanical and electrical response of the device are calculated as a superposition of eigenmodes according to voltage drive at one electrical port at a time while extracting current induced in the other ports, leading to a full Y-parameter description of the device. Exemplary cases are simulated to show the usefulness of the model in the study of the basic design rules of laterally coupled thin film BAW resonator filters. Model predictions are compared to an experimental 1.9-GHz band-pass filter based on aluminum nitride thin film technology and lateral acoustical coupling. Good agreement is obtained in prediction of passband behavior. The eigenmode-based model forms a useful tool for fast simulation of laterally coupled acoustic devices. It allows one to gain insight into basic device physics in a very intuitive fashion compared with more detailed but heavier finite element method. Shortcomings of this model and possible improvements are discussed.
建立了一个二维模型，用于计算相邻薄膜体声波（BAW）谐振器之间的侧向声学耦合，这些谐振器形成电 N 端口。该模型基于相邻区域的横向本征模和本征频率的解和叠加，这些区域具有已知的板波色散特性。根据每次在一个电端口施加电压，设备的机械和电气响应被叠加为本征模，同时提取其他端口感应的电流，从而得到设备的完整 Y 参数描述。模拟示例显示了该模型在研究横向耦合薄膜 BAW 谐振器滤波器的基本设计规则中的有用性。模型预测与基于氮化铝薄膜技术和侧向声学耦合的 1.9GHz 带通滤波器的实验结果进行了比较，在通带行为的预测方面取得了很好的一致性。基于本征模的模型为横向耦合声学器件的快速仿真提供了有用的工具。与更详细但更重的有限元方法相比，它可以更直观地了解基本器件物理。讨论了该模型的缺点和可能的改进。
