PROPAGATION CHARACTERISTICS OF SURFACE ACOUSTIC-WAVES IN ZNO/LINBO3 STRUCTURES

In this paper, we report that the propagation characteristics of surface acoustic waves (SAWs) in a structure consisting of a piezoelectric layer on a piezoelectric substrate depend on the relationship between the polarities of the two piezoelectric media. The theoretical analysis of the characteristics of the Rayleigh wave in ZnO/128-degrees-rotated Y-cut LiNbO3 structures shows that there is a large difference in values of electromechanical coupling factor K in the two cases where the ZnO layer is deposited on the positive surface and the negative surface of LiNbO3, and that the value of K2 can be as high as 13.3%. The mode coupling phenomenon between the Rayleigh and Love waves is also discussed.