Microwave dielectric ceramic composition and preparing method thereof
US5457076A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 18, 1994 |
| Grant date | Oct 10, 1995 |
| Priority date | — |
| Expiry date | Aug 18, 2014 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L2924/3011
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
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.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.