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:
Aug. 17, 2004
Filed:
Oct. 21, 2002
Tomoki Fukagawa, Amagasaki, JP;
Kazuhiro Nishikawa, Nagaokakyo, JP;
Sumitomo Special Metals Co., Ltd., Osaka, JP;
Abstract
A dielectric ceramic composition wherein the dielectric constant ∈ is large, the temperature coefficient &tgr;f of the resonance frequency is close to 0, and which as a large Q value, is obtained by adding to and blending with a ceramic composition whose &tgr;f of the resonance frequency is large on the plus side a ceramic composition whose temperature coefficient &tgr;f is large on the minus side. In an Li O—R O —TiO -based composition, an improved dielectric constant ∈ can be achieved by introducing a specific quantity of Bi O , and &tgr;f can be shifted to the plus side and in addition a considerable improvement in Qf achieved by introducing a specific quantity of MO, where M is one or two of Ca and Sr. Furthermore, by introducing a specific quantity of Na O together with the MO (where M is one or two of CA and Sr), in particular in the case of material of ∈r>150, it is possible to control &tgr;f to the vicinity of 0 while maintaining Qf at an high value.