Fast procedure for the nonlinear analysis of BAW resonators

Abstract

This work presents the development of a Matlab software tool based on a non-iterative method for the nonlinear analysis of Bulk Acoustic Wave (BAW) resonators and filters. The procedure starts with the admittance matrix extraction of the distributed circuit that models a resonator. The aim of this procedure is to avoid high computation times and/or convergence problems that usually appear when performing Harmonic Balance (HB) simulations of very large circuits, as those resulting from a distributed model of a BAW resonator with a high discretization level. Moreover, the procedure allows to simulate the potential isolated contribution of each nonlinear coefficient that appear in the constitutive equations with a low penalty in terms of computation time. As an example, this analysis capability is integrated with an optimization algorithm that is able to find the first order nonlinear coefficients that better match the second harmonic (H2) broadband measurements of a device.