SURFACE-ACOUSTIC-WAVE TRANSDUCER IN A LAYERED STRUCTURE COMPOSED OF THIN PIEZOELECTRIC CERAMIC PLATE AND GLASS

Operation performance of a surface acoustic wave (SAW) interdigital transducer (IDT) in a layered structure composed of a thin piezoelectric ceramic plate and a glass substrate is described in terms of phase velocity, electromechanical coupling constant and mechanical displacement distributions. The numerical results of SAW phase velocities in the form of a function of the product of frequency and thickness of the piezoelectric ceramic plate are in good agreement with the measured velocities of the constructed layer-structured devices. The first-order SAW mode device has an excellent electromechanical coupling constant of greater than 15%, which is favorable for a SAW device exhibiting a satisfactory performance under single-mode operation in a SAW oscillator construction.