New closed form two-dimensional COM analysis of SAW filters

The coupling-of-modes (COM) analysis is generalized to take into consideration the two-dimensional (2D) effects concerned the SAW excitation/detection and propagation/scattering processes. The modeling is applicable to SAW devices in the general case when non-waveguide transducers are weighted in both withdrawal and apodization manners simultaneously with possible slanted overlapping and change of electrodes polarity. Uniform internal reflections and possible radiation directivity of the ITDs (including "natural directionality effect") is taken into account. Doubly apodized filter having two apodized in-line transducers, including SPUDTs, may be analyzed in the model frame. The quasi-optics approach to the angular spectrum method is applied to describe approximately the diffraction spreading and beam steering in such a system.