Patent ID: 6707229
Filing Date: 2004-03-16
Classification: H03H

Abstract:
A surface acoustic wave filter on the basis of interdigital single-phase unidirectional transducers (SPUDT-type), in connection with which two of such transducers are arranged on a piezoelectrical substrate with distributed acoustic reflection, such transducers being composed of groups of fingers and collector electrodes, wherein:(a) The electrodes of each transducer form a structure tapering in the direction of the fingers; and (b) The structure is tapered in the direction of the fingers so that not only the width of equivalent fingers and gaps, but also the intermediate space between the two transducers only vary by one and the same factor along the parallel straight lines, wherein said lines of all fingers of both transducers intersect one another in such a manner that in each transducer, the spacings of the center lines of equivalent fingers are the same in all groups of fingers.