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:
Jan. 20, 2009
Filed:
Feb. 24, 2006
Fumio Asamura, Saitama, JP;
Kenji Kawahata, Saitama, JP;
Katsuaki Sakamoto, Saitama, JP;
Nihon Dempa Kogyo Co., Ltd., Tokyo, JP;
Abstract
A high-frequency filter includes a substrate; a ground conductor disposed on one main surface of the substrate and having an opening; a center conductor making up a coplanar line resonator together with the substrate and the ground conductor; and an input line and an output line each of which has a microstrip line structure and is disposed on the other main surface of the substrate to electromagnetically couple with the center conductor. At least one of the input line and the output line has a closed loop line portion surrounding a corresponding end of the center conductor and crossing the center conductor transversely through the substrate. On the other main surface of the substrate, a stub overlapping with the center conductor is arranged from a transverse position where the closed loop line portion crosses the center conductor.