The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Mar. 11, 2003
Filed:
Feb. 20, 2001
Michio Kadota, Kyoto, JP;
Junya Ago, Nagaokakyo, JP;
Hideya Horiuchi, Nagaokakyo, JP;
Mamoru Ikeura, Nagaokakyo, JP;
Murata Manufacturing Co., LTD, Kyoto, JP;
Abstract
An edge reflection type surface acoustic wave filter includes a piezoelectric substrate having two opposing edges and at least one interdigital transducer. The interdigital transducer includes split electrodes of paired electrode fingers arranged on the piezoelectric substrate such that a shear horizontal (SH-type) surface acoustic wave is excited on the piezoelectric substrate and is reflected between the two opposing edges. Each of the edges is preferably located at a distance of at least about &lgr;/2−5&lgr;/128 from a center of the paired equipotential electrode fingers, located at the respective outermost portions, in the surface acoustic wave propagation direction, of the interdigital transducer and less than about &lgr;/2 from the center of the paired equipotential electrode fingers, where &lgr; is a wavelength of the SH-type surface acoustic wave excited on the piezoelectric substrate.