Patent ID: 6469598
Filing Date: 2002-10-22
Classification: H03H

Abstract:
A Surface Acoustic Wave (SAW) filter comprising:a piezoelectric substrate; and least two interdigital transducers (IDTs) formed of four fingered electrodes disposed in a region corresponding to one wavelength of a surface acoustic wave excited on said piezoelectric substrate, wherein at least one of said IDTs having at least one pair of fingered electrodes, each electrode of said one pair of fingered electrodes having a different electrode width to obtain propagation unidirectionality, electrode width ratio of said at least one pair of fingered electrodes of said IDT is different from electrode width ratio of at least one other pair of fingered electrodes of said IDT, and distance between electrodes of said at least one pair of fingered electrodes of said IDT is different from distance between electrodes of at least one other pair of fingered electrodes of said IDT.