Anisotropic superlattice transducers: characteristics and models

Recent experiments have demonstrated the practicability of superlattice transducers for bulk acoustic waves in the high GHz frequency range. The transducers consisted of multilayers of ZnO with alternating crystal orientations. The authors describe a procedure for calculating the electromechanical characteristics of general multilayer transducers in which the individual layers are anisotropic and piezoelectric and have arbitrary crystal orientation. The algorithm is numerically stable and easily implemented for use on a personal computer using commercial software. A network model is also derived which provides both an approximate analysis of multilayer transducer performance and an insight into synthesis procedures. Examples compare the two approaches and illustrate an initial design procedure for broadband transducers