Method of optimizing input impedance of surface acoustic wave filter

Abstract

Methods of designing band-pass filters are disclosed. A baseline filter design is established, the baseline filter design including a plurality of surface acoustic wave resonators having respective resonant frequencies, the surface acoustic wave resonators organized by resonant frequency into two or more groups. One or more alternative filter designs are established, each alternative filter design derived from the baseline filter design by reordering the resonant frequencies of two or more surface acoustic wave resonators within at least one of the two or more groups. A respective performance metric related to input impedance over a pass band is calculated for each of the baseline filter design and the alternative filter designs. A final filter design is selected from the baseline filter design and the alternative filter designs based on the respective performance metrics.