ASA 125th Meeting Ottawa 1993 May

5pPA12. Electroacoustic waves in a piezoelectric-layered structure under periodic metal gratings.

Youxin Zhu

Zhiming Wu

Dingguo Cai

Zingjiao Li

Dept. of Solid State Electron., Huazhong Univ. of Sci. and Technol., Wuhan 430074, People's Republic of China

The propagation of electroacoustic waves in a piezoelectric-layered structure under periodic metal gratings is investigated. A general theory that fits both the elastic and electric periodic boundary conditions has been developed and is applicable to a grating with an arbitrary electrical connection between adjacent metal strips. Numerical works are given. It is found that the considered electroacoustic waves, which penetrate deep into the substrate in the absence of the metal grating, become trapped at the interface between the substrate and the surface layer when the grating is presented. It is noted that the penetrate depth is heavily dependent on the grating thickness. The electroacoustic wave penetration depth can be adjusted by a proper design of the grating structure to minimize the acoustic power density in the layered structure. The relevant attributes of the wave such as particle displacement electrical potential, and dispersion are also computed and analyzed. Some practical application in acoustoelectronics are suggested. [Work supported by NNSF.]