IEEE Trans Ultrason Ferroelectr Freq Control. 2017 Sep;64(9):1354-1360. doi: 10.1109/TUFFC.2017.2702671. Epub 2017 May 9.
This paper discusses lateral propagation of surface acoustic waves (SAWs) in periodic grating structures when two types of SAWs exist simultaneously and are coupled. The thin plate model proposed by the authors is extended to include the coupling between two different SAW modes. First, lateral SAW propagation in an infinitely long periodic grating is modeled and discussed. Then, the model is applied to the Al-grating/42° YX-LiTaO (42-LT) substrate structure, and it is shown that the slowness curve shape changes from concave to convex with the Al grating thickness. The transverse responses are also analyzed on an infinitely long interdigital transducer on the structure, and good agreement is achieved between the present and the finite-element method analyses. Finally, SAW resonators are fabricated on the Cu grating/42-LT substrate structure, and it is experimentally verified that the slowness curve shape of the shear horizontal SAW changes with the Cu thickness.
本文讨论了当两种类型的表面声波（SAWs）同时存在并发生耦合时，周期性光栅结构中表面声波的横向传播。作者提出的薄板模型扩展到包括两种不同 SAW 模式之间的耦合。首先，对无限长周期性光栅中的横向 SAW 传播进行了建模和讨论。然后，将该模型应用于 Al 光栅/42°YX-LiTaO（42-LT）衬底结构，结果表明，随着 Al 光栅厚度的增加，慢度曲线的形状从凹变凸。还对结构上无限长的叉指换能器进行了横向响应分析，结果与有限元法分析吻合较好。最后，在 Cu 光栅/42-LT 衬底结构上制作了 SAW 谐振器，实验验证了剪切水平 SAW 的慢度曲线形状随 Cu 厚度的变化。
