Surface acoustic wave interdigital transducer with compensated diffraction, has acoustic path divided by sub-transducers to give relatively low overall diffraction

摘要

The interdigital transducer (MPW) has an excitation function implemented using overlapping weighting. n electrically-connected sub-traducers (TW) of small aperture Aj and relatively high diffraction, divide the acoustic path of the interdigital transducer into n parallel sub-paths. The sub-transducers each have an aperture A1, and all have the same excitation function such as sin(x)/x, so that the total aperture is the sum from 1 to n of Aj, where n is a positive integer greater than or equal to 3. An Independent claim is also included for the use of an interdigital transducer for implementing a symmetrical transfer function.