Stress-induced frequency shifts in langasite thickness-mode resonators

In this paper, we report on our study of stress induced effects on thickness vibrations of a langasite plate. The plate is assumed to be doubly rotated, specified by angles phi and thetas . The stresses are assumed to be uniform and planar. The first-order perturbation integral as developed by Tiersten for frequency shifts in resonators is used. The dependence of frequency shifts on phi and thetas is calculated and examined, and loci of stress-compensation are determined.