Robust optimum design of SAW filters by using penalty function method

The frequency response characteristics of surface acoustic wave (SAW) filters are governed primarily by their geometrical structures, i.e., the configurations of interdigital transducers (IDTs) and grating reflectors fabricated on piezoelectric substrates. In the process of designing optimal structures for SAW filters, computer-aided design techniques utilize theoretical model of IDT for estimating their performances. In this paper, considering dispersion of uncertain parameters included in IDT's model, the robust design of SAW filters is formulated as a constrained optimization problem. Then, a new penalty function method combined with a variable neighborhood search (VNS) is applied to the optimization problem. Computational experiments conducted on a practical design of SAW filter demonstrate the usefulness of the proposed robust design approach.