Modeling the selectivity of SAW filter with single phase unidirectional transducer based on FEM and equivalent circuit model

Abstract

This study uses FEM and Mason simulation methods to evaluate the selectivity of the bandpass SAW filter with SPUDT structure. The results show that when changing the width of the asymmetric finger of the IDT, the selectivity of the filter is changed. Specifically, the asymmetric finger width of 15 µm showed better selectivity than the equivalent structure with the asymmetric finger width of 5 µm. The results are consistent with the explanatory theory of previous research methods. Besides, the application of the SPUDT structure model test to the Masson model has shown an improvement in the selectivity of the SAW filter