A first generation CAD compiler for surface acoustic wave filters using bidirectional transducers

Abstract

An automation system has been developed for the design and analysis of SAW (surface acoustic wave) bidirectional transducers and filters and has been implemented on a personal-computer-class workstation. All dominant SAW acoustic and electrical effects have been modeled for nonreflecting transducers in a modular architecture. These synthesis and analysis tools form the core of the design-automation system. An automation shell used with the design tools forms the basis of a SAW compiler that is capable of noninteractive filter design. The first-generation set of SAW-filter design rules is implemented in a declarative language that provides logical-decision control of the automation system. The highest level of design choices, such as synthesis technique, transducer weighting, and substrate material, has been implemented in the design-rule system. The design-automation system controls the execution and iteratively evaluates options, corrects errors, and decides on an optimum design choice within the set of design rules. The system accepts user input of a frequency-domain specification and noninteractively outputs a filter meeting these specifications. A design automation system example is shown and experimental results using the CAD (computer-aided design) tools are presented. >