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:
Dec. 14, 1999
Filed:
Mar. 30, 1998
Masao Gamo, Takaoka, JP;
Murata Manufacturing Co., Ltd., Kyoto, JP;
Abstract
A piezoelectric filter is arranged to suppress unnecessary vibrations caused by wiring patterns such as lead-out electrodes to improve filter characteristics. The filter includes a filter section having a pair of resonant electrodes located on an upper surface of a piezoelectric substrate, and a common electrode located on the lower surface of the substrate so as to be opposite to the resonant electrodes. A capacitor connected to the filter section includes a capacitive electrode having the function of a lead-out electrode and located on the upper surface of the piezoelectric substrate, and another capacitive electrode located on the lower surface of the piezoelectric substrate. Lead-out electrodes extend to edges of the piezoelectric substrate. The piezoelectric substrate is unpolarized in a region where at least a portion of the lead-out electrodes is located and in a vicinity of this region.