Analysis of surface acoustic waves obliquely propagating under metallic gratings with finite thickness

In this paper we propose a method of analysing surface acoustic waves (SAWs) propagating obliquely under a metallic grating with finite thickness. The discrete Green function originally developed for SAWs longitudinally propagating under the metallic grating is modified, and applied to the characterisation of obliquely propagating SAWs. The method is applied to the analysis of Rayleigh SAM's obliquely propagating on 128 degrees YX-LiNbO3 (128-LN), and the result is shown to be in good agreement with experiments, Leaky SAWs obliquely propagating on 36 degrees YX-LiTaO3 (36-LT) are also analysed and compared with the result obtained for 128-LN.