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Maki Yonetsu

Maki Yonetsu, Tokyo JP

Patent application numberDescriptionPublished
20090058750HIGH-FREQUENCY MAGNETIC MATERIAL AND ANTENNA DEVICE USING THEREOF - A superior high-frequency magnetic material having a smaller ratio (μ″/μ′) of the real part μ′ of permeability and the imaginary part μ″ of permeability in a high-frequency region and an antenna device using thereof are provided. The high-frequency magnetic material includes a substrate and a composite magnetic film formed on the substrate that consists of a magnetic phase forming a plurality of columnar bodies whose longitudinal direction is directed in a direction perpendicular to a surface of the substrate and an insulator phase filling gaps of the columnar bodies, and the magnetic phase is amorphous and has in-plane uniaxial anisotropy of Hk03-05-2009
20090079650HIGH-FREQUENCY MAGNETIC MATERIAL AND ANTENNA SYSTEM USING THEREOF - A superior high-frequency magnetic material having a smaller ratio (μ″/μ′) of a real part μ′ of permeability and an imaginary part μ″ of permeability in a high-frequency region and an antenna system using thereof are provided. The high-frequency magnetic material includes a substrate and a composite magnetic film formed on the substrate and made of a magnetic phase forming a plurality of columnar bodies whose longitudinal direction is directed in a direction perpendicular to a surface of the substrate and an insulator phase filling gaps of the columnar bodies. The magnetic phase contains at least one of Nb, Zr, and Hf, and Fe and B, is amorphous, and has in-plane uniaxial anisotropy of Hk2/Hk1≧3 and Hk2≧3.98×1003-26-2009
20090169951MANUFACTURING METHODS OF CATALYSTS FOR CARBON FIBER COMPOSITION AND CARBON MATERIAL COMPOUND, MANUFACTURING METHODS OF CARBON FIBER AND CATALYST MATERIAL FOR FUEL CELL, AND CATALYST MATERIAL FOR FUEL CELL - The carbon fibers of this invention is characterized in that irreducible inorganic material particles in a mean primary particle size below 500 nm and reducible inorganic material particles in a mean primary particle size below 500 nm were mixed by pulverizing and then, the mixture was heat treated under the reducing atmosphere and metal particles in a mean particle size below 1 μm were obtained, and the mixed powder of the thus obtained metal particles with the irreducible inorganic material particles are included in the carbon fibers.07-02-2009
20090295662ANTENNA DEVICE - The present invention provides a small antenna device realizing both miniaturization including lower profile and a broader band in a frequency band of hundreds MHz to 5 GHz and which can be mounted on a small device such as a cellular phone. An antenna device includes: a finite ground plane; a rectangular conductor plate provided above the finite ground plane, whose one side is connected to the finite ground plane, and having a bent portion substantially parallel with the one side; an antenna disposed substantially parallel with the finite ground plane above the finite ground plane, extending in a direction substantially perpendicular to the one side, and having a feeding point positioned near the other side facing the one side of the rectangular conductor plate; and a magnetic material provided in at least a part of space between the finite ground plane and the antenna.12-03-2009
20100060538CORE-SHELL MAGNETIC MATERIAL, METHOD OF MANUFACTURING CORE-SHELL MAGNETIC MATERIAL, DEVICE, ANTENNA DEVICE, AND PORTABLE DEVICE - The present invention provides a core-shell magnetic material having an excellent characteristic in a high frequency band, particularly, in a GHz band. The core-shell magnetic material includes: core-shell magnetic particles including magnetic metal particles and an oxide coating layer, the magnetic metal particle containing magnetic metal selected from the group of Fe, Co, and Ni, nonmagnetic metal selected from the group of Mg, Al, Si, Ca, Zr, Ti, Hf, Zn, Mn, a rare-earth element, Ba, and Sr, and an element selected from carbon and nitrogen, and the oxide coating layer being made of an oxide containing at least one nonmagnetic metal as one of the components of the magnetic metal particle; and oxide particles existing at least a part between the magnetic metal particles and containing nonmagnetic metal selected from the group of Mg, Al, Si, Ca, Zr, Ti, Hf, Zn, Mn, a rare-earth element, Ba, and Sr, and in which nonmagnetic metal/magnetic metal (atomic ratio) in the particles is higher than that in the oxide coating layer.03-11-2010
20100060539CORE-SHELL MAGNETIC MATERIAL, METHOD OF MANUFACTURING CORE-SHELL MAGNETIC MATERIAL, DEVICE, AND ANTENNA DEVICE - The present invention provides a core-shell magnetic material having an excellent characteristic in a high frequency band, particularly, in a GHz band. The core-shell magnetic material includes: core-shell magnetic particles including magnetic metal particles and an oxide coating layer, the magnetic metal particle containing magnetic metal selected from the group of Fe, Co, and Ni, nonmagnetic metal selected from the group of Mg, Al, Si, Ca, Zr, Ti, Hf, Zn, Mn, a rare-earth element, Ba, and Sr, and an element selected from carbon and nitrogen, and the oxide coating layer being made of an oxide containing at least one nonmagnetic metal as one of the components of the magnetic metal particle; and oxide particles existing at least a part between the magnetic metal particles and containing nonmagnetic metal selected from the group of Mg, Al, Si, Ca, Zr, Ti, Hf, Zn, Mn, a rare-earth element, Ba, and Sr, and in which nonmagnetic metal/magnetic metal (atomic ratio) in the particles is higher than that in the oxide coating layer.03-11-2010

Patent applications by Maki Yonetsu, Tokyo JP

Maki Yonetsu, Mitaka-Shi JP

Patent application numberDescriptionPublished
20080267806Method of manufacturing high frequency magnetic material - A precursor particle having a particle size of 10 nm or more and 1 μm or less, and comprising a first compound selected from an alkoxide, a hydroxide, a sulfate, a nitrate, a carbonate, or a carboxylate of magnetic metal containing at least one metal of Fe and Co, and a second compound selected from an alkoxide or a hydroxide, a sulfate, a nitrate, a carbonate, or a carboxylate of a metal element for forming an oxide, is prepared. Then the precursor particle is heated in a reducing atmosphere to form an insulating particle made of an oxide of the metal element by decomposing the second compound, and to precipitate a particle of the magnetic metal in the insulating particle at a particle size of 1 nm or more and 100 nm or less, thereby manufacturing a high frequency magnetic material.10-30-2008
20090021444HIGH-IMPEDANCE SUBSTRATE - A high-impedance substrate is provided, which includes a metallic plate employed as a ground plane, a resonance circuit layer spaced away from the metallic plate by a distance “t”, the resonance circuit layer being provided with at least two resonance circuits having the same height and disposed side by side with a distance “g”, a connecting component connecting the resonance circuit with the metallic plate, and a magnetic material layer interposed between the metallic plate and the resonance circuit layer. The distance “t” between the metallic plate and the resonance circuit layer is confined within the range of 0.1 to 10 mm, the distance “g” between neighboring resonance circuits is confined within the range of 0.01 to 5 mm, the distance “h” between the magnetic material layer and the resonance circuit layer is confined within the range represented by the following inequality 1:01-22-2009

Patent applications by Maki Yonetsu, Mitaka-Shi JP