Theoretical determination of the pseudo surface acoustic wave characteristic parameters

A method of determining the characteristic parameters of the surface acoustic wave (SAW) and pseudo SAW (PSAW) for two electric surface conditions, free and metallized, is described. Valuations of the coupling factors, K², for free and metallized surfaces can be deduced from the characteristic parameters. They are in accordance with the classical definition 2ΔV/V for K² for some Rayleigh SAWs (RSAWs). However, for Bluestein-Gulyaev SAWs (BGSAWs), PSAWs, and a number of RSAWs, the three possible valuations of K²f are widely different. This means that the wave cannot be fully characterized by a single value of K² and depends strongly on the electric surface conditions. Thus, the study of the wave for free and fully metallized surfaces does not permit one to predict its behavior when a periodic grating is deposited on the surface