EQUIVALENT NETWORKS FOR SAW INTERDIGITAL TRANSDUCERS

An equivalent network approach is described for the analysis of surfac e-acoustic-wave interdigital transducers. Circuit parameters can be th eoretically determined by applying the finite-element method to an inf inite array. In this approach, all the effects of piezoelectric pertur bation, mechanical perturbation, and energy storage are taken into acc ount. To show the validity and usefulness of this approach, examples a re computed for both single- and double-electrode interdigital transdu cers and one-port resonators. For single- and double-electrode interdi gital transducers on 128-degrees-Y XLiNbO3, X 112-degrees-Y LiTaO3, 45 -degrees-X Z Li2B4O7, and ST(g) X quartz substrates, the dependence of excitation characteristics on electrode thickness and metallization r atio is investigated in detail. For a 128-degrees-Y-X LiNbO3 substrate , frequency responses of various one-port resonators are also investig ated.