Finite element analysis of SAW-transducers

It is shown that the simulation of an unweighted SAW-filter based on the numerical solution of the complete set of differential equations governing piezoelectric media is possible with an acceptable computational effort using piezoelectric finite elements. The excellent agreement between calculated impedance matrix, transmission coefficient, group delay, and their measured values proves the validity of the simulation process. These calculations are used to optimize the SAW-transducers and to obtain deeper insight into the wave propagation processes in piezoelectric SAW-devices. This simulation permits the study of parasitic effects introduced by bulk waves or the geometrical expansion of the electrodes