Stress-induced frequency shifts in langasite thickness-mode resonators

In this paper, we report on our study of stressinduced effects on thickness vibrations of a langasite plate. The plate is assumed to be doubly rotated, specified by angles ϕ and θ. 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 ϕ and θ is calculated and examined, and loci of stress-compensation are determined.