Abstract
This paper proposes a robust optimum design technique for Surface Acoustic Wave (SAW) filters. The frequency characteristics of SAW filters are governed primarily by their geometrical structures, namely, both of the configurations and the arrangements of Interdigital Transducers (IDTs) fabricated on piezoelectric substrates. For deciding optimal structures of SAWfilters, traditional design techniques estimate their frequency characteristics based on the equivalent circuit mode of IDT. However, they have rarely considered the reliability of the equivalent circuit mode of IDT even though it may be spoiled by the scattering of parameters' values. In the robust optimum design of SAW filters, the proposed design technique employs a penalty function method combined with a variable neighborhood search and counts errors due to inaccuracy of the equivalent circuit mode of IDT. Computational experiments conducted on an optimum design of a practical three-IDT type SAW filter demonstrate the usefulness of the proposed design technique.
