Patent ID: 6429569
Filing Date: 2002-08-06
Classification: H03H

Abstract:
A surface acoustic wave device comprising:a piezoelectric substrate; a first interdigital transducer provided on a surface of the piezoelectric substrate; a second interdigital transducer provided on the surface of the piezoelectric substrate such that the second interdigital transducer is offset from a direction in which a surface acoustic wave excited by th e first IDT propagates; a first edge provided on the piezoelectric substrate to reflect the excited surface acoustic wave to the first and second interdigital transducers; and a first coupler having a plurality of metal strips and disposed on the piezoelectric substrate, the first coupler provided between the first edge of the piezoelectric substrate and at least one of the first and second interdigital transducers so as to be adjacent to the first and second interdigital transducers; wherein the surface acoustic wave device operates using a shear horizontal surface acoustic wave and the first coupler is arranged to transmit shear horizontal surface acoustic waves without reflecting the shear horizontal surface acoustic waves; and said first edge is spaced from a center of the metal strip closest to said first edge at a distance that is substantially equal to an integer multiple of approximately W/2, where W is a sum of a width of the metal strip and a space between the metal strips.