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:
Dec. 23, 1997
Filed:
Nov. 17, 1995
Kojiro Okuyama, Nara, JP;
Koji Shimoyama, Hyogo, JP;
Syunichiro Kawashima, Kyoto, JP;
Koichi Kugimiya, Osaka, JP;
Matsushita Electric Industrial Co. Ltd., Osaka, JP;
Abstract
The present invention provides dielectric ceramics with less variation of temperature coefficient at a resonant frequency due to heating history during the sintering of ZrTiO.sub.4 and ZrO.sub.2 --SnO.sub.2 --TiO.sub.2 ceramics, and having a high unloaded Q value and a high dielectric constant, and a temperature coefficient at a resonant frequency which is widely variable as desired, and dielectric resonators using the dielectric ceramics which have a high unloaded Q value and a strong electrode layer. The main components of the dielectric ceramics may be expressed by the formula: xZrO.sub.2 --yTiO.sub.2 --zA.sub.(1+u)/3 B.sub.(2-u)/3 O.sub.2 wherein A denotes at least one component selected from the group (A) consisting of Mg, Co, Zn, Ni and Mn, B denotes at least one component selected from the group (B) consisting of Nb and Ta, and x, y, z and u (x, y and z are molar fractions and u is a value within the range from 0 to 1.90) have the relation of x+y+z=1.0, 0.10.ltoreq.x.ltoreq.0.60, 0.20.ltoreq.y.ltoreq.0.60, 0.01.ltoreq.z.ltoreq.0.70. The main component may include, as accessory components, at least one component selected from the group (C) consisting of Ba, Sr, Ca, Cu, Bi and W at 0.005 to 7.000% by weight of the entire weight of the ceramic.