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:
Mar. 14, 2006
Filed:
Oct. 02, 2003
Tomoya Maekawa, Nara, JP;
Hiroshi Shigemura, Kyotanabe, JP;
Tomoya Maekawa, Nara, JP;
Hiroshi Shigemura, Kyotanabe, JP;
Matsushita Electric Industrial Co., Ltd., Osaka, JP;
Abstract
A duplexer is composed of a laminate in which dielectric layers and electrode layers are laminated alternately. A first filter for transmitting and a second filter for receiving, having different pass band frequencies, are provided in the laminate. A matching circuit composed of a coupling line, having one end that is short-circuited and the other end that is connected to an external terminal, is provided between the first filter and the second filter. The first filter includes two first stripline resonators, each having one end that is short-circuited. The second filter includes two second stripline resonators, each having one end that is short-circuited. The coupling line is coupled to the first stripline resonator dose to the coupling line by electromagnetic field coupling. The coupling line is coupled to the second stripline resonator close to the coupling line by electromagnetic coupling.