SSBW to PSAW conversion in SAW devices using heavy mechanical loading

The development of efficient computation tools based on mixed analytical and numerical calculation approaches allows precise descriptions and characterizations of Surface Acoustic Wave (SAW) propagation. In this work, such a theoretical model is used to analyze the evolution of Pseudo Surface Acoustic Waves (PSAW) on standard YX Lithium Tantalate cuts versus Aluminum strip height. It is shown that the Surface Skimming Bulk Wave (SSBW) which accompanies the PSAW on such crystal orientations may be trapped by the grating, exhibiting a PSAW-like behavior when close to the Bragg condition. The consequences of this phenomenon are discussed.