Fast modeling of lateral modes in BAW resonators with arbitrary in-plane geometry

The Transmission Line Matrix (TLM) method is used to model and predict lateral spurious resonances in a BAW resonator. The dispersive characteristics of the main propagating mode, which are defined by the stack of materials, are considered with dispersive transmission lines along the in-plane lateral directions of the resonator. The particle displacement profiles obtained with the TLM method are coupled to the electric domain. From these, the input impedance of the resonator is obtained. This allows for fast simulations of the lateral resonances using nodal admittance matrices.