On universal two-dimensional modeling of SAW devices with complex architectures

Highly efficient modeling is proposed to describe the SAW devices with complex in-line architectures. Arbitrary distribution of reflective arrays and electrode cells (or their blocks) inside a non-waveguide acoustic track is simulated using the novel matrix technique (SEA method). The only assumption is that the reflectivity in each cross-section over the working domain is uniform, though it may be changed arbitrarily over the longitudinal direction. Both withdrawal and apodization weighting techniques are simply taken into account in the presence of propagation loss. Possible transverse shift of the overlapping centers as well the voluntary cell connections to the input or output bus-bars are considered in a natural way too. Practically all "second-order" effects and parasitic analysis are involved into consideration simultaneously. Diffraction spreading and beam steering effects for a "single track" system are taken into account using the Angular Spectrum of Waves method which is generalized to describe the SAW systems with distributed feedback (DFB). In particular, analytical solution of the diffraction problem in DFB systems is found for elliptic form of the substrate slowness curve.