Tdk Corporation

Shin Takane

Yasuharu Miyauchi

Yousuke Futamata

Yuta Ashida

Shigemitsu Tomaki

Takuya Aoki

Kenichi Sakai

Kosuke Kunitsuka

Tomokazu Ishikura

Kazunari Kimura

Norizumi Asano

A glass ceramic sintered body having a small dielectric loss in a high frequency band of 10 GHz or higher and a wiring substrate using the same are provided. The glass ceramic sintered body contains crystallized glass, an alumina filler, and silica. The content of the crystallized glass is 45 mass % to 85 mass %, the content of the alumina filler is 14.8 mass % to 50.1 mass % in terms of AlO, and the content of silica is 0.2 mass % to 4.9 mass % in terms of SiO.

Glass ceramic sintered body and wiring substrate

A glass ceramic sintered body having a small dielectric loss in a high frequency band of 10 GHz or higher and stable characteristics against temperature variation and a wiring substrate using the same are provided. The glass ceramic sintered body contains crystallized glass, an alumina filler, silica, and strontium titanate. The content of the crystallized glass is 50 mass % to 80 mass %, the content of the alumina filler is 15.6 mass % to 31.2 mass % in terms of AlO, the content of silica is 0.4 mass % to 4.8 mass % in terms of SiO, and the content of the strontium titanate is 4 mass % to 14 mass % in terms of SrTiO.

A dielectric filter includes a plurality of dielectric resonators. The dielectric filter also includes: a plurality of resonator body portions each formed of a first dielectric and respectively corresponding to the plurality of dielectric resonators, the first dielectric having a first relative permittivity; a peripheral dielectric portion formed of a second dielectric and lying around the plurality of resonator body portions, the second dielectric having a second relative permittivity lower than the first relative permittivity; and a shield portion formed of a conductor. Either one of a temperature coefficient of resonant frequency of the first dielectric at 25&#xb0; C. to 85&#xb0; C. and a temperature coefficient of resonant frequency of the second dielectric at 25&#xb0; C. to 85&#xb0; C. has a positive value and the other has a negative value.

Dielectric resonator and dielectric filter

An object is to provide a ferrite composition suitable for an antenna element with a long communication distance in a high-frequency band (for example, 13.56 MHz), a ferrite plate formed of the ferrite composition, a magnetic member for an antenna element formed of the ferrite plate, and an antenna element provided with a member for an antenna element. A ferrite composition, wherein: main components contain, with FeOconversion, 45.0-49.5 mol % of iron oxide, with CuO conversion, 4.0-16.0 mol % of copper oxide, with ZnO conversion, 19.0-25.0 mol % of zinc oxide, a remaining portion is constituted by nickel oxide, an inevitable impurity is removed with respect to the main components, and as accessory components, with TiOconversion, 0.5-2 weight % of titanium oxide, with CoO conversion, 0.35-2 weight % of cobalt oxide are contained.

Ferrite composition, ferrite plate, member for antenna element, and antenna element

The temperature properties of the initial permeability of a Ni&#x2014;Cu&#x2014;Zn based ferrite material are improved while the degradation of the magnetic properties of the ferrite material is being suppressed. The ferrite material is formed of a sintered body comprising, as main constituents, FeO: 47.0 to 50.0 mol %, CuO: 0 to 7 mol %, NiO: 13 to 26 mol %, and ZnO substantially constituting the balance, wherein the sintered body comprises 40 ppm or less of P in terms of POand 50 to 1800 ppm of one or more additives of AlO, CaO and MgO in relation to the sum of the contents of the main constituents. In the Ni&#x2014;Cu&#x2014;Zn based ferrite material, the mean grain size can be set at 12 &#x3bc;m or less and the standard deviation of the grain size can be set at 4.5 &#x3bc;m or less.

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Tokyo, Japan

Shin Takane