Accurate and fast two-dimensional analysis of long, apodized SAW-transducers

The authors present a novel rigorous approach to the two-dimensional analysis of SAW (surface acoustic wave) transducers, which is based on three steps. First the 2-D charge distribution on the IDT (interdigital transducer) is computed. This is done efficiently by means of a 2-D element factor which accounts for the transversal end effects near the gaps. Wave excitation is described by means of the elementary angular spectrum of waves (ASW), derived from the SAW-part of the 2-D Green´s function. Wave propagation is modeled by the well-known ASW formalism. It is concluded that considering transversal end effects and modeling wave excitation rigorously gives better correspondence with measurements than a quasi-1-D analysis