Simulation of wireless passive SAW sensors based on FEM/BEM model

Research on the wireless passive surface acoustic wave (SAW) impedance-loaded sensors has received significant attention in recent years. This paper concentrates on the simulation method of these sensors. In our previous work, the coupling-of-modes (COM) model of impedance-loaded SAW sensors was constructed based on the models of SAW IDT. The accuracy of this model depends on the accuracy of their parameters. A numerical combined finite element method and boundary element method (FEM/BEM) model was used to derive COM parameters more accurately in this paper. We used a finite element method to account for the mass loading effect of electrodes and use a Green's function to model the piezoelectric substrate. Comparison between simulations and measurements on real SAW devices shows good agreement and proofs the effectiveness of this simulation method.