An Analysis of Reflection Characteristics of Surface-Acoustic-Wave Gratings

A coupled mode theory has been applied to surface-acoustic-wave gratings in order to study both the fundamental and higher harmonic operations of the reflective gratings. Coupling coefficients can be theoretically determined by applying the finite-element method to an infinite array. To show the validity and usefulness of this approach, examples are computed for aluminum strips on an X-112°Y LiTaO3 substrate. Both the fundamental and second harmonic responses are treated. The computed results agree well with the experimental results.