Efficient 3-D Finite Element Modeling of Periodic XBAR Resonators

Abstract

An efficient technique is presented for 3D finite element modeling of large-scale periodic XBAR resonators in the time-harmonic domain. In this technique, a domain decomposition scheme is employed to decompose the computational domain into many small subdomains whose FE subsystems can be factorized with a direct sparse solver at a low cost. Transmission conditions are enforced to interconnect adjacent subdomains, and a global interface system is formulated and solved iteratively. To accelerate the convergence, a second-order transmission condition (SOTC) is designed to make the subdomain interfaces transparent for propagating and evanescent waves. An effective forward-backward preconditioner is constructed that, when combined with the SOTC, significantly reduce the number of iterations at no additional cost. Numerical results are given to demonstrate the accuracy, efficiency, and capability of the proposed algorithm.