Transformation of surface acoustic waves into boundary waves in Piezoelectric/Metal/Dielectric structures

A universal technique was developed for analysis of SAW and boundary waves (BW) in Piezoelectric/Metal/Dielectric structures with uniform metal film sandwiched between piezoelectric substrate and dielectric overlay, and dielectric overlay thickness varying between zero and infinite value. This technique was applied to 128°YX LN with Cu and silica glass films. For each mode propagating in this structure, continuous transformation of the wave polarization and distribution of its energy along the vertical axis were analyzed as functions of metal and dielectric film thickness. The found dependences reveal the mechanisms of wave transformation from SAW to BW.