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. 23, 1999
Filed:
Apr. 25, 1997
Chang-Hwa Lee, Daejeon, KR;
Meyng-Soo Kim, Daejeon, KR;
Bon-Hee Koo, Daejeon, KR;
Dong-Suk Jun, Daejeon, KR;
Sang-Seok Lee, Daejeon, KR;
Tae-Goo Choy, Daejeon, KR;
Electronics and Telecommunications Research Institute, Daejeon, KR;
Korea Telecommunication, Seoul, KR;
Abstract
A duplexer having dual coupled line characteristics is disclosed. With a small number of resonators and without using an external device such as a chip inductor or a chip capacitor, the signals of the receiving frequency can be improvingly damped. The diameters of the transmitting terminal dielectric filter resonators and the receiving terminal dielectric filter resonators are not same, but their diameters at an open terminal and at a short circuit terminal are made different from each other so as to differentiate a coupling amount at the short circuit terminal from that at the open terminal. Further, the transmitting terminal filter resonators and the receiving terminal dielectric filter resonator are provided in a form of grooves, and sizes of the grooves near the open terminal are made different from those of the grooves near the short circuit terminal so as to differentiate a coupling amount of the resonators at the short circuit terminal from those at the open terminal. The duplexer of the present invention is used in the transmission/receiving separate type filter of the mobile communication.