单根电极或沟槽形成的栅格对声表面波的散射

摘要

该文借鉴汪承灏先生研究栅格声表面波散射的技术路线,提出一种既不限制基片和栅格形状、类型,也不限制声波入射方向,可精确计算栅格对SAW散射的有限元通用模型.作为对《超声学》第六章"声表面波"中栅格对声表面波的反射和体波散射一节部分结论的进一步阐释和说明,计算了YZ-LiNbO3和128?YX-LiNbO3单晶上厚度为200 nm、宽度为1 μm的单根悬浮铝栅条以及沟槽在不同频率下的反射系数曲线.提出的计算方法今后可推广应用于层状结构基底、应用到非规则指条、沟槽、金属点阵、基片端面、台阶等的反射的精确分析,为优化设计新型声表面波器件奠定理论基础.%This paper reviews the research progress of the surface acoustic wave scattering from gratings on piezoelectric substrate. Based on Wang Chenghao's method, this paper extends it to a general model for arbitrary substrates, grating shapes and wave incidence angles using the finite element method. As examples, the frequency dependent SAW reflections of an aluminum electrode and a groove with the width of 1 micron and the height/depth of 2000 Armstrong on YZ-LiNbO3and 128?YX-LiNbO3substrate are calculated and discussed.