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:
May. 16, 2000
Filed:
Jul. 16, 1998
Applicant:
Inventors:
Assignee:
Murata Manufacturing Co., Ltd., Kyoto, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H03H / ;
U.S. Cl.
CPC ...
333192 ; 333191 ; 310340 ; 310349 ; 310366 ;
Abstract
A piezoelectric filter has a significantly reduced size and a sufficient coupling capacitance while avoiding an uneven outer configuration of an overall shape of the filter. The piezoelectric filter includes a first resonating unit and a second resonating unit and a coupling capacitance unit disposed in a piezoelectric substrate. The coupling capacitance unit is provided with a first coupling capacitance electrode located on an upper surface of the piezoelectric substrate and a second coupling capacitance electrode located on a lower surface thereof and the first and second coupling capacitance electrodes are arranged to extend to side edge surfaces of the piezoelectric substrate.