Hitachi Metals, Ltd.

Other

Keiko Kikuchi

Hiroyuki Aoyama

Masahiro Masuzawa

Hiroshi Okabe

Yuta Sugiyama

Masahiro Mita

Shigeho Tanigawa

Eriko Takeda

Yasunori Takaki

Satoru Tanaka

Yoshihiko Kuriyama

Takeshi Tachibana

Toru Abe

Hiroki Hamakake

Hidetoshi Hagiwara

Kenichi Tonomura

A method for analyzing the DC superposition characteristics of an inductance device using an electromagnetic field simulator, comprising a first step of determining an initial magnetization curve from initial magnetization to saturation magnetization, and pluralities of minor loops at different operating points, on a toroidal core made of the same magnetic material as that of the inductance device, and obtaining point-list data showing the relation between magnetic flux density or magnetic field strength and incremental permeability from the incremental permeability at each operating point; a second step of determining an operating point at a predetermined direct current on each element obtained by mesh-dividing an analysis model of the inductance device by an electromagnetic field simulator based on the initial magnetization curve of the core, allocating the incremental permeability to the operating point from the point-list data, and integrating the inductance of each element obtained from the incremental permeability to determine the inductance of the entire inductance device; and a third step of repeating the second step at different direct current levels to determine the DC superposition characteristics.

Method for analyzing DC superposition characteristics of inductance device, and electromagnetic field simulator

A rotor comprising bonded magnet portions mainly composed of magnet powder and a binder, which are embedded in a soft magnetic portion mainly composed of soft magnetic powder and a binder, the rotor being produced by a compression-molding method, and the magnetic pole surfaces of the bonded magnet portions being embedded in the soft magnetic portion.

Rotor and process for manufacturing the same

Provided is an annular reactor core formed of a U-shaped core and core legs. Core joints including end portions and two protrusions form the U-shaped core. Between the protrusions of these core joints, a plurality of (two) core legsformed of core blocks are arranged so as to have gaps and the protrusions. The ratio A/B, which is a ratio of the length A of the protrusions of the core joint to the average length B of the core blocks constituting the core legs in a magnetic path direction, is optimized so as to be not less than 0.3 but not more than 8.0, whereby an increase in copper loss due to leak magnetic fluxes of the gap portions is suppressed.

Reactor core and reactor

A polar-anisotropic ring magnet having magnetization directions in alignment with its normal line at each magnetic pole position and in alignment with its tangential line at each middle position between adjacent magnetic poles, and having a substantially constant angle difference in a magnetization direction between adjacent elements, the elements being obtained by division at an equal angle pitch between the magnetic pole position and the middle position adjacent to the magnetic pole position.

Magnetic-field molding apparatus

An magnetic-field-generating apparatus comprising permanent magnet segments arranged to form a ring-shaped magnetic circuit having a center hole; adjacent permanent magnet segments having such different magnetization directions that their magnetization directions successively change along a circumferential direction of the magnetic circuit; a basic magnetization phase angle &#x3b8; between the magnetization directions of the adjacent permanent magnet segments being 720/N (&#xb0;); and a magnetization direction of at least one permanent magnet segment in an essential unit obtained by circumferentially dividing the ring to &#xbc; being deviated from the basic magnetization phase angle &#x3b8; by such a deviating angle that a uniform magnetic flux flows in one direction along a diameter of the center hole.

Magnetic-field-generating apparatus and magnetic field orientation apparatus using it

A surface-mounted antenna comprising a substrate made of a high-dielectric constant material having a dielectric constant &#x2208;of 6 or more, a ribbon-shaped radiation electrode having one end which is grounded and the other end which is open, a grounding electrode connected or capacitance-coupled to one end of the radiation electrode, and a current-feeding electrode in a portal shape formed on a side surface separate from the radiation electrode with a gap; the current-feeding electrode having a current-feeding portion at one end, a grounding portion at the other end, and a portion substantially in alignment with the radiation electrode between them; and the length of the aligning portion, a gap width or a portal shape being able to be properly set such that capacitance owned by the current-feeding electrode and inductance can be adjusted for easily achieving impedance matching.

Surface-mounted antenna and communications apparatus comprising same

To provide an antenna element having a radiation electrode formed mainly on one surface of a dielectric substrate. The radiation electrode is substantially symmetric in form with respect to the center thereof, and has a first half and a second half with the same direction of main polarization of radiation emitted therefrom. Each of the halves of the radiation electrode may be a quarter-wave antenna for a wavelength of the emitted radiation. A power supply conductor to be connected to a high frequency signal source is connected to the first half of the radiation electrode, and a ground conductor to be connected to a ground is connected to the second half. A total impedance of the first half of the radiation electrode and the power supply conductor and a total impedance of the second half of the radiation electrode and the ground conductor can substantially match to one another, so that resonance between the halves of the radiation electrode can be enhanced and a wider bandwidth can be realized.

Antenna element

A chip antenna element comprises (a) a radiation electrode formed on at least one surface of an insulating substrate, such that the radiation electrode extends from a first end of the substrate or its vicinity to a second end of the substrate or its vicinity, with a width decreasing substantially continuously and/or stepwise, thereby having a wide rear end on the side of the first end of the substrate and a narrow tip end on the side of the second end of the substrate, (b) a first grounding electrode connecting directly or via a gap to the rear end of the radiation electrode, (c) a second grounding electrode opposing the tip end of the radiation electrode via a gap, and (d) a feeding electrode formed on at least one surface of the substrate at a position facing an intermediate point of the radiation electrode, with or without contact with the radiation electrode.

Growing community of inventors

Saitama-ken, Japan

Keiko Kikuchi