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:
Oct. 10, 1995
Filed:
Aug. 18, 1994
Hiroshi Katagiri, Aichi, JP;
Hirofumi Ozeki, Aichi, JP;
NGK Spark Plug Co., Ltd., , JP;
Abstract
A ceramic composition having a high value .epsilon.r while maintaining Qu and .tau.f each in a range of practical characteristic. The present invention is applicable to dielectric resonators and impedance matching of various kinds of microwave circuits. The ceramic composition comprises Ba.sub.1-x Sr.sub.x (Zn.sub.1/3 Nb.sub.2/3)O.sub.3 (in which 0.6.ltoreq..times..ltoreq.1.0) as the main ingredient, to which TiO.sub.2 is incorporated by 0.01 to 1 parts by weight based on 100 parts by weight of the main ingredient. The ceramic composition may have a Qu value of 2000 to 2900 (at 4.5 GHz), relative dielectric constant of 39 to 42, and a temperature constant of resonance frequency (.tau.f) in the range of -8 to +10 ppm/.degree.C. The ceramic composition may not contain Sr.sub.5 Nb.sub.4 O.sub.15 or Ba.sub.4 Nb.sub.2 O.sub.9. It may index for the regularity of the B site ingredient of 7-9.times.10.sup.-2. The ceramic composition may be prepared by calcination, sintering, and an annealing treatment after sintering. A calcination atmosphere and a sintering atmosphere may be ZnO atmosphere.