Murata Manufacturing Co., Ltd.

Murata Mfg. Co., Ltd.

Takehiro Konoike

Kunisaburo Tomono

Hiroshi Marusawa

Takashi Kodama

Hiroshi Takagi

Takashi Kawanami

Hiroshi Tamura

Akihiro Nakamura

Hideo Ajichi

Kazunari Kawahata

Takashi Hasegawa

Gaku Kamitani

Junji Kurobe

Kunishaburo Tomono

A coil antenna structure includes a first magnetic component extending in the thickness direction of a tabular primary casing. A second magnetic component and a third magnetic component, which are magnetically connected to the first magnetic component, are disposed on the first principal surface side and the second principal surface side of the primary casing, respectively. The first magnetic component is provided with a coil component surrounding it. In this manner, a U-shaped magnetic path is provided at an end portion of the primary casing so as to detour around a substrate defining an internal conductor. Likewise, a U-shaped magnetic path including fourth to sixth magnetic components is provided in a secondary casing defining a clamshell type casing together with the primary casing so as to detour around a substrate defining as an internal conductor.

Coil antenna structure and portable electronic apparatus

A laminated electronic component includes a composite obtained by integrally sintering a plurality of laminated magnetic layers, internal conductors being formed in the interior of the composite. The internal conductor and the magnetic layers constitute a plurality of inductance elements, or an inductance element and a capacitance element. The magnetic layer has a composition containing a primary component comprising 45 to 50 mole percent Fe O , 0 to 33 mole percent ZnO, and 6 to 20 mole percent CuO, and the balance being NiO, and a Mn compound wherein the Mn compound is contained in an amount of 0.01 to 2.0 weight percent as MnO in the composition.

Laminated electronic component

A method of manufacturing a ferrite sintered body includes the steps of: adding B,C in a ferrite raw material and firing the ferrite raw material, whereby the ferrite sintered body has a high &mgr;i and a high Q, is less irregular in its characteristics, has a high volume resistivity and is capable of preventing deterioration of insulating resistance.

Method of manufacturing ferrite sintered body

A method of producing a Ni&mdash;Cu&mdash;Zn ferrite material comprises the steps of preparing a mixture of an iron compound powder having a specific surface area of about 8.5 m,/g or more, a nickel compound powder, copper compound powder and a zinc compound powder, the mixture having a specific surface area of about 8.0 m,/g or more; pre-calcining the mixture such that the pre-calcined mixture has a surface area of about 5.0 m,/g or more and a spinel crystal synthesizability within a range of about 80.5% to 98%; and milling the pre-calcined mixture to obtain a powder of a Ni&mdash;Cu&mdash;Zn ferrite material having a specific surface area of about 6.0 m,/g or more.

Method of producing Ni-Cu-Zn ferrite material

A microwave non-reciprocal circuit element which is further miniaturized and of low losses without causing conductor losses in center electrodes following miniaturization. The microwave non-reciprocal circuit element according to the present invention comprises a plurality of center electrodes which are arranged to intersect with each other in a state electrically insulated from each other, and a microwave magnetic or dielectric body which is arranged on an intersecting portion of the plurality of center electrodes, and the respective center electrodes are formed by a plurality of conductors 55, 56 and 57 which are stacked through the microwave magnetic or dielectric body.

Microwave non-reciprocal circuit element

A magnetic material for high frequencies consists essentially of a main component expressed by the general formula:

Magnetic material for high frequencies

A high-frequency use non-reciprocal circuit includes a sintered body which is a high-frequency use magnetic body obtained by a ceramic lamination/integral firing technique, a plurality of central electrodes which are arranged in the sintered body to be separated from each other through a magnetic layer while intersecting with each other at central portions, and electrodes for deriving impedance-matching capacitance which are formed in the vicinity of the intersecting portion to be in series with the central electrodes. The magnetic layer provided between the central electrodes serves as an insulating layer for electrically insulating the central electrodes from each other, a high-frequency use magnetic layer, and a material layer for deriving the impedance-matching capacitance.

High-frequency use non-reciprocal circuit element

A magnetic material for mircowave and millimeter wave frequencies consists essentially of a basic composition and at least one additive incorporated therein, the basic composition being represented by the general formula:

A dielectric ceramic composition for microwave frequencies comprises a solid solution of BaO, SnO.sub.2, MgO and Ta.sub.2 O.sub.5, said solid solution being represented by the general formula:

Dielectric ceramic composition for microwave frequencies

A high frequency dielectric ceramic composition is described, said composition being represented by the formula: Ba(Zr.sub.x Zn.sub.y Ta.sub.z)O.sub.7/2-x/2-3y/2, wherein 0.02.ltoreq.x.ltoreq.0.13, 0.28.ltoreq.y.ltoreq.0.33 and 0.59.ltoreq.z.ltoreq.0.65 (where x+y+z=1). The ceramic composition has a complex perovskite structure, provides a high dielectricity and high Q value at high frequency and selectively provides a temperature coefficient of resonant frequency with a center value of 0 ppm/.degree.C., without using high sintering temperatures and/or long sintering times.

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Yasu, Japan

Takehiro Konoike