Electronics and Telecommunications Research Institute

Korea Telecommunication Authority

Korea Telecom

Jung-Rae Park

Tae-Hong Kim

Tae-Goo Choy

Sang-Seok Lee

Suk-Jin Lee

Tae-Goo Choi

A material for microwave band devices used by the general people and in industrial electronic apparatuses is disclosed. Particularly, a magnetic ceramic composition for use in microwave devices, a magnetic ceramics for use in microwave devices and a preparation method therefore are disclosed, in which the saturation magnetization can be easily controlled, and a low ferri-magnetic resonance half line width and an acceptable curie temperature are ensured. The magnetic ceramic composition for microwave devices includes yttrium oxide (Y.sub.2 O.sub.3), iron oxide (Fe.sub.2 O.sub.3), tin oxide (SnO.sub.2), aluminum oxide (Al.sub.2 O.sub.3) and a calcium supply source. The magnetic ceramics for the microwave devices are manufactured by carrying out a forming and a sintering after mixing: yttrium oxide, iron oxide, tin oxide, aluminum oxide and calcium carbonate (or calcium oxide) based on a formula shown below. It has a saturation magnetization of 100-1,800 G at the normal temperature, a temperature coefficient for the saturation magnetization of 0.2%/.degree.C., and a ferri-magnetic resonance half line width of less than 60 Oe, Y.sub.3-x Ca.sub.x/2 Sn.sub.x/2 Fe.sub.5-y Al.sub.y O.sub.12 where 0.1.ltoreq.x.ltoreq.1, and 0.1.ltoreq.y.ltoreq.1.5.

Magnetic ceramic composition for use in microwave devices, magnetic

The present invention relates to a dielectric ceramic composition for microwave which consists of BaO, Sm.sub.2 O.sub.3, TiO.sub.2 and PbO, and has a compositional formula of x(Ba.sub.1-.alpha., Pb.sub..alpha.)O-- ySm.sub.2 O.sub.3 -zTiO.sub.2, wherein 6 mol % .ltoreq.x.ltoreq.20 mol %, 6 mol %.ltoreq.y.ltoreq.20 mol %, 60 mol %.ltoreq.z.ltoreq.75 mol % and 0 mol % .ltoreq..alpha..ltoreq.0.2 mol %. Accordingly, since the dielectric ceramic composition for microwave according to the present invention has the dielectric constant more than 85, the temperature factor of the resonant frequency within .+-.5 ppm/.degree.C., and the quality factor more than 6000 in 1 GHz, it can be utilized in the filter for microwave, the dielectric for the resonator, the laminated ceramic capacitor, the dielectric for the filter for electromagnetic wave obstacle and the dielectric for capacitor. And also, since it is possible to reduce the problems to the volatilization of the plumbic oxide and the bismuth oxide, the dielectric ceramic composition for microwave according to the present invention can be made by a general manufacturing process and can reduce the use of the elements detrimental to the human body.

Dielectric ceramic composition for microwave

The present invention relates to dielectric ceramic compositions for microwave applications consisting of BaO, PbO, Nd.sub.2 O.sub.3, CeO.sub.2, La.sub.2 O.sub.3 and TiO.sub.2 or consisting of compositions including these elements and having a composition formula (I).

Dielectric ceramic compositions for microwave

Growing community of inventors

Daejeon, South Korea

Jung-Rae Park