MODELS FOR MULTI-REGION SAW WAVEGUIDES ON ANISOTROPIC SUBSTRATES

THE PROPOSED RESEARCH WILL DEVELOP A MORE ACCURATE METHOD FOR ANALYZING SAW DEVICES BASED ON MODELING A SAW TRANSDUCER AS AN ACOUSTIC WAVEGUIDE. APPROXIMATE ANALYSIS HAS SHOWN THAT IN MOST CASES, THE LOWEST ORDER TRANSDUCER WAVEGUIDE MODES HAVE UNDESIRABLE MODE SHAPES THAT TEND TO CONCENTRATE ENERGY UNDER THE BUS BARS ON EITHER SIDE OF THE STRUCTURE. A MORE COMPLEX TRANSDUCER STRUCTURE IS PROPOSED WHICH SHOULD GREATLY IMPROVE THE LOWEST ORDER MODE SHAPES AND HENCE IMPROVE THE PERFORMANCE OF VIRTUALLY ALL TYPES OF SAW DEVICES. THE GOALS OF THE PROPOSED PROGRAM ARE (1) DEVELOP THE MODELING TECHNIQUES NEEDED TO ANALYZE COMPLEX TRANSDUCER STRUCTURES, (2) DEVELOP METHODS FOR ANALYZING THE EFFECTS OF SUBSTRATE ANISOTROPY, AND (3) DEVELOP METHODS FOR ACCURATELY MEASURING THE CHARACTERISTICS OF TRANSDUCER WAVEGUIDE MODES.