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

Abstract

Abstmct-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 o p timization problem. In order t o 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 prcposed and applied to the optimization problem successfully. The proposed local search is applicable generally t o the structural design of various SAW devices.

Frequency Response Optimization of Saw Filter using Canonical Genetic Algorithm

“…For example, a common design technique based on the delta-function model of IDT employed an iterative algorithm to yield an optimum SAW filter. We also applied a local search to the optimum design problem of a resonator type SAW filter [10], where we used the least equivalent circuit model of IDT. Unfortunately, we could rarely obtain a globally optimal or near-optimal structure of the SAW filter only by the local search, because the local optimization method doesn't have the ability to survey a vast region of the search space [8,9,11].…”