Kyocera Corporation

Toyomi Nishi

Nobuyoshi Fujikawa

Seiichiro Hirahara

Shinichi Enami

Hideki Utaki

A dielectric ceramic composition which contains a rare earth element (Ln), Al, Ca and Ti as metal elements and which when these components are expressed in terms of a mole ratio as aLn.sub.2 O.sub.x.bAl.sub.2 O.sub.3. cCaO.dTiO.sub.2, the values of a, b, c, d and x satisfy a+b+c+d=1, 0.056.ltoreq.a.ltoreq.0.214, 0.056.ltoreq.b.ltoreq.0.214, 0.286.ltoreq.c.ltoreq.0.500, 0.230.ltoreq.d.ltoreq.0.470, and 3.ltoreq.x.ltoreq.4. The dielectric having the above composition is disposed between a pair of input and output terminals to constitute a dielectric resonator. The dielectric ceramic composition exhibits such dielectric properties as a large dielectric constant at high frequencies, a large Q-value and a small temperature coefficient of resonance frequency. Satisfactory properties are exhibited when the dielectric ceramic composition is used for a resonator or as a material of circuit board for high-frequency applications.

Dielectric ceramic composition and dielectric resonator

A dielectric ceramic composition having a composition (mole %) expressed by the formula xMgO.yLa.sub.2 O.sub.3. xTiO.sub.2 wherein x, y and z are numerals that lie within a range surrounded by a line that couples the points a, b, c, d and e in FIG. 1. The composition can contain 0.01 to 3% by weight of MnO.sub.2 with respect to chief components consisting of the above three components. The composition can be effectively used as a resonator or a circuit board in the microwave frequency region.

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Kokubu, Japan

Toyomi Nishi