Enhancing effects of microcavities on shear-horizontal surface acoustic wave sensors: A finite element simulation study

Abstract

Shear-horizontal surface acoustic wave (SAW) sensors with microcavities in the delay paths of 36° YX-LiTaO3 substrate were studied using finite element methods. Microcavities of square cross sections of sizes λ∕4 and λ∕2 and of different depths were located in the middle of the delay path. Simulation results for nonfilled and polystyrene-filled microcavity devices were compared with standard delay line shear-horizontal SAW, optimized Love-wave, and etched grating sensors. We found that the best case microcavities studied reduce insertion loss by 19.25dB from 33.28dB and exhibit velocity sensitivity 4.83 times larger than that of the standard SAW sensor simulated.