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:
Sep. 12, 2000
Filed:
Oct. 24, 1997
NGK Spark Plug Co., Ltd., Nagoya, JP;
Abstract
Dielectric materials are disclosed that are based on BaO--ZnO--Ta.sub.2 O.sub.5 represented by the formula Ba(Zn.sub.1/3 Ta.sub.2/3)O.sub.3. Ba has been partly replaced by K and either Zn or Ta has been replaced by at least one element selected from Mg, Zr, Ga, Ni, Nb, Sn. The dielectric materials have a relatively high permittivity, a small absolute value of the temperature coefficient of resonance frequency, and a high unloaded quality factor. A method for producing the dielectric materials is also disclosed which includes mixing given amounts of starting materials, such as, for example, BaCO.sub.3, ZnO, Ta.sub.2 O.sub.5, K.sub.2 CO.sub.3, MgCO.sub.3, SnO.sub.2 or ZrO.sub.2, compacting the mixture to produce a compact, sintering the compact in an oxidizing atmosphere such as, for example, air, at 1,400 and 1,600.degree. C., more preferably at 1,550 to 1,600.degree. C. for 2 hours, and then heating the sintered compact at a temperature lower than the sintering temperature by from 50 to 250.degree. C., e.g., by 100.degree. C., for at least 12 hours, preferably for 24 hours. A dielectric resonator comprising the dielectric material of the present invention is also disclosed.