Patent ID: 6774536
Filing Date: 2004-08-10
Classification: H03H

Abstract:
A surface acoustic wave device comprising:a piezoelectric substrate; first and second bus bars formed on said piezoelectric substrate; an interdigital transducer having a first set of plural electrode fingers and a second set of plural electrode fingers connected with said first and second bus bars, respectively, said first and second sets of electrode fingers being arranged in an interdigital configuration; and a crossover area on which said first and second sets of electrode fingers of said interdigital transducer are disposed in an alternate fashion; wherein each boundary line between each of said first and second bus bars and a grating formed of said first and second sets of electrode fingers is not parallel to a group velocity direction of a surface acoustic wave excited on said interdigital transducer, wherein the center line of each electrode finger on said crossover area is not aligned with the center line of an opposing non-crossover electrode finger, and wherein a distance between the center line of each electrode finger on said crossover area and the center line of an opposing non-crossover electrode finger is in a range of {fraction (1/16)} to {fraction (7/16)} of an interdigital pattern period of electrode fingers on said crossover area in each of said first and second sets of electrode fingers, whereby a ripple in the characteristic impedance located to the lower frequency side of the resonant frequency is suppressed.