Murata Manufacturing Co., Ltd.

Hiroaki Kikuta

Takaya Wada

Daiji Kono

A nonreciprocal circuit device (2-port isolator) includes a ferrite-magnet assembly including a ferrite, a first center electrode, and a second center electrode. The ferrite is sandwiched between a pair of permanent magnets and receives a direct-current magnetic field applied thereto. The first and second center electrodes are arranged on the ferrite. The ferrite includes a center layer and an outer layer ensuring an insulation state of the first and second center electrodes. The saturation magnetization of the outer layer is larger than the saturation magnetization of the center layer.

Nonreciprocal circuit device

A nonreciprocal circuit device (2-port isolator) includes a ferrite-magnet assembly including a ferrite, a first center electrode, and a second center electrode. The ferrite is sandwiched between a pair of permanent magnets and receives a direct-current magnetic field applied thereto. The first and second center electrodes are arranged on the ferrite. The ferrite includes a center layer and an outer layer ensuring an insulation state of the first and second center electrodes. The saturation magnetization of the outer layer is smaller than that of the center layer.

An electronic component including a magnetic member comprising an iron oxide magnetic composition, a nonmagnetic member in contact with the magnetic member and including a glass ceramic composite composition, and an internal conductor portion disposed in at least one of the magnetic member and the nonmagnetic member. The glass ceramic composite composition includes crystallized glass as a main component, and quartz as a sub-component filler. The crystallized glass contains 25 percent by weight to 55 percent by weight of SiO, 30 percent by weight to 55 percent by weight of MgO, 5 percent by weight to 30 percent by weight of AlO, and 0 percent by weight to 30 percent by weight of BO, and the content of the quartz is 5 percent by weight to 30 percent by weight relative to 100 percent by weight of the crystallized glass.

Electronic component

A high-frequency magnetic ceramic comprises garnet ferrite represented by the formula A B O wherein the site A comprises yttrium and the site B comprises iron, where Z is in the range of more than 3.00 to 3.09. The relative density of the high-frequency magnetic ceramic is at least 95%, the average grain diameter is at least 3 &mgr;m, and the 3&sgr; value of the grain diameters is 2 &mgr;m or less wherein &sgr; represents the standard deviation of the grain diameters. A high-frequency circuit component includes microwave magnetic composites composed of the high-frequency magnetic ceramic and central electrodes that are mutually insulated.

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Moriyama, Japan

Hiroaki Kikuta