Optimal design of three-IDT type SAW filter using local search

An optimal design approach for surface acoustic wave (SAW) filters is presented. First of all, the structural design of a three-IDT type SAW filter, which consists of three interdigital transducers (IDT) and two reflectors, is formulated as a combinatorial optimization problem. In order to simulate the frequency response of the SAW filter, the least equivalent circuit model of IDT is employed. Then, a new local search technique based on the k-degree-neighborhood is proposed and applied to the optimization problem successfully. The proposed local search is applicable generally to the structural design of various SAW devices.