Automatic design technique based on nonlinear optimization for SAW devices

An improved automatic design technique based on nonlinear optimization method will be reported. The number of interdigital transducer (IDT) electrodes are treated as continuous function vector with the other design parameters, the IDT position, the IDT aperture and the external element constants etc. The procedure is applied to the interstage filter for digital mobile terminals which consists of two different substrates. We also apply the technique to high performance SAW antenna duplexers for digital mobile terminals and miniature SAW IF filters for automatic electrical toll collection systems. The performance of these devices is found to be in good agreement with the design predictions.