Practical implementation of coupling-of-modes theory for SAW device modeling

Procedures are presented for integrating the COM (coupling-of-modes) results of C.S. Hartmann and B.P. Abbott (1988) into a form useful for modeling an entire SAW (surface acoustic wave) device. Conversion of the three-port P-matrix COM solutions into a standard two-port ABCD matrix form is shown. With the resultant ABCD matrix, graphical results are shown for the full SAW device model including second-order effects and matching circuitry. These results are presented for different types of SAW devices such as those with uniform, apodized, and withdrawal-weighted transducers and are compared with conventional approaches to SAW modeling. Experimental results for various device configurations and metal thicknesses are shown for comparison with predicted model results. In general there is close agreement between experiment and the implementation of COM theory reviewed