The propagation behavior of Love waves in a functionally graded layered piezoelectricstructure

Abstract

The propagation behavior of Love waves in a functionally graded layered piezoelectricstructure is investigated in this paper. It involves a thin piezoelectric layer, in which theparameters vary linearly in the thickness direction, bonded perfectly to an elastic substrate.By the WKB method, the phase velocity equations are obtained for both electrical openand short cases on the free surface, respectively. The results show that the circularfrequency and cut-off frequency increase as the elastic modulus and dielectric constant varylinearly respectively; meanwhile, the number of vibration modes decreases, and the coupledelectromechanical factor increases with the decrease of the dielectric constant.Undoubtedly, this is useful for the design of surface acoustic wave (SAW) devices.