Mechanical-electro-thermal coupling analysis of 3D RF MEMS-BAW filters chip based on the FEM method

This article presents a mechanical-electro-thermal multi-physical field analysis method for three-dimensional (3D) bulk acoustic wave (BAW) filter modeling. Based on the finite element method (FEM), the energy dissipation problem caused by the electrode loss on the chip in the 3D BAW filter model is investigated. Firstly, the 3D multi-order filter is modeled and simulated, so that the impedance curves of each resonator unit are obtained by mechanical-electro coupling simulation. Secondly, the electromagnetic simulation is carried out to get the S-parameters of the filter through the transformed dielectric constant, the simulation calculation results are compared with the test data. Finally, the electromagnetic-thermal simulation shows the effect of loss on the chip, to investigate the mechanical-electro-thermal coupling effect in the RF BAW filter.