Analysis of surface acoustic wave resonance properties on piezoelectric substrates with periodic voids

The resonance properties of leaky surface acoustic waves (LSAWs) and longitudinal LSAWs (LLSAWs) on bonded structures consisting of a LiNbO3 (LN) thin plate and a support substrate, with periodic voids exhibiting a rectangular cross-section, were simulated using the finite element method. The voids were formed below the electrode at the boundary between the LN thin plate and support substrate and presented the same pitch and period as the electrode. LN, quartz, glass, or Si were used as support substrates. Simulations revealed that by introducing periodic voids, resonance properties similar to those of the SH0-mode plate and S0-mode Lamb waves can be obtained. The values of the simulated fractional bandwidths of approximately 13 and 18% were found for LSAW and LLSAW, respectively, when the ratio of the width of the void to the pitch of the electrode was 0.7.