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:
Oct. 15, 1991
Filed:
Feb. 20, 1990
Murata Mfg. Co. Ltd., , JP;
Abstract
A piezoelectric filter device of an energy-trapped type utilizing a higher harmonic in the thickness-extensional vibration mode, having a plate-shaped body made of a piezoelectric material. At least three electrodes are arranged so as to overlap each other while being separated by layers of the piezoelectric material in the direction of thickness of the plate-shaped body. At least one of the electrodes comprises a plurality of divided electrodes which are substantially coplanar. At least one of the divided edlectrodes constitutes an input terminal and at least one of the remaining divided electrodes constitutes an output terminal. A region of the body, around the vibrating region, where the electrodes are overlapped with each other, is uniformly subjected to polarization processing in the direction of thickness.