IEEE Trans Ultrason Ferroelectr Freq Control. 2018 Jun;65(6):1062-1068. doi: 10.1109/TUFFC.2018.2820011.
This paper investigates piston mode operation (PMO) when two kinds of surface acoustic waves (SAWs) exist and are coupled to each other. The extended thin plate model is used for the analysis. First, a PMO condition is derived in a closed form. It is verified that PMO is possible without adding phase shifters by the use of two SAW coupling. It is also shown that this operation offers suppression of the transverse modes for a wider frequency range than the conventional PMO. Then, parameters defined in the model are extracted for various SiO-overlay/Al-grating/128° YX-LiNbO substrate structures, and the structure satisfying the PMO condition is designed. Finally, the structure is also analyzed using the 3-D finite element method. The result agrees well with that calculated by the extended thin plate model.
本文研究了存在两种表面声波（SAW）并相互耦合时的活塞模式操作（PMO）。采用扩展的薄板模型进行分析。首先，以封闭形式推导出 PMO 条件。通过使用两个 SAW 耦合，验证了无需添加移相器即可实现 PMO。还表明，与传统的 PMO 相比，这种操作提供了更宽的频率范围的横向模式抑制。然后，针对各种 SiO 覆盖层/Al 光栅/128°YX-LiNbO 衬底结构提取模型中定义的参数，并设计满足 PMO 条件的结构。最后，使用 3-D 有限元法对该结构进行分析。结果与扩展的薄板模型的计算结果吻合较好。
