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. 12, 1996
Filed:
Feb. 17, 1995
Applicant:
Inventors:
Tatsuo Ogawa, Aichi, JP;
Yasuhiko Nakagawa, Aichi, JP;
Assignee:
NGK Spark Plug Co., Ltd., Aichi, JP;
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H03H / ;
U.S. Cl.
CPC ...
333189 ; 310357 ; 333191 ; 333186 ;
Abstract
A ladder type piezoelectric filter of the present invention is made usable in high frequency ranges by employing a piezoelectric resonator having the second harmonic wave mode SM. A series resonator and a parallel resonator of the ladder type piezoelectric filter of the present invention are so arranged that center electrode regions and outer electrode regions are mutually polarized along opposite directions, and the center electrode regions are connected to the outer electrode regions, respectively.