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:
Nov. 02, 1999
Filed:
Jan. 15, 1998
Murata Manufacturing Co., Ltd., Kyoto, JP;
Abstract
A transversal-coupled resonator type surface acoustic wave filter includes a piezoelectric substrate and first and second interdigital transducers. The piezoelectric substrate has a pair of substrate edges which are substantially parallel to each other and reflect a shear horizontal type surface wave excited and propagated on a surface of the piezoelectric substrate in a direction perpendicular to the substrate edges. The first and second interdigital transducers have the same resonance characteristics and are provided on the piezoelectric substrate. Each of the first and second interdigital transducers includes a pair of outermost electrode fingers which are arranged to be flush with the substrate edges of the piezoelectric substrate, respectively and a pair of adjacent electrode fingers which are adjacent to the pair of the outermost electrode fingers, respectively. A distance D' from one of the substrate edges of the piezoelectric substrate to a center of the corresponding adjacent electrode fingers satisfies the following inequalities: