High-frequency choke coil
AssigneeMurata Manufacturing Co., Ltd.
InventorsKouichi Yamaguchi, Tatsuyuki Yamada, Yukio Sakamoto, Masami Sugitani, Satoshi Murata
Life of this patent
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Abstract
A soft magnetic core is substantially cylindrical and a linear-shaped coil conductor is inserted through a hole in the central portion of the soft magnetic core. A hard magnetic material sheet has areas which are magnetized in a thickness direction thereof and the areas are arranged in strips so that a magnetization direction of adjacent strips is mutually opposite. The hard magnetic material is wound on the outside surface of the soft magnetic core and is fixed to the soft magnetic core. The direction of the areas formed as strips of the hard magnetic material is substantially perpendicular to the axial direction of the coil conductor.
Claims17
A high-frequency choke coil comprising:
- a soft magnetic core having an opening extending therethrough;
- a hard magnetic material having at least a pair of areas having mutually opposite magnetization directions and being disposed around said soft magnetic core such that said magnetization directions are nearly perpendicular to the surface of said soft magnetic core;
- and
- a coil conductor disposed inside of said soft magnetic core and extending through said opening in said soft magnetic core;
- wherein said soft magnetic core and sail coil conductor are arranged such that a magnetic field that is nearly perpendicular to a magnetic field produced by a current flowing through said coil conductor is produced inside said soft magnetic core and causes ferrimagnetic resonance to be produced inside said soft magnetic core so as to increase an impedance in a high-frequency range.
A high-frequency choke coil comprising:
- a soft magnetic core having an opening extending therethrough;
- a coil conductor disposed inside of said opening in said soft magnetic core;
- a hard magnetic material having at least a pair of areas having mutually opposite magnetization directions and being disposed around said soft magnetic core such that said magnetization directions are nearly perpendicular to the surface of said soft magnetic core;
- and
- a hard magnetic material magnetized in a nearly perpendicular direction relative to a surface of said soft magnetic core and disposed around said soft magnetic core such that a magnetic field produced by a current flowing through said coil conductor and a magnetic field produced by said hard magnetic material intersect nearly at right angles with each other.
A core holder comprising:
- a ring-shaped soft magnetic core having a hole extending therethrough;
- a hard magnetic material having at least a pair of areas having mutually opposite magnetization directions and being disposed around said soft magnetic core such that said magnetization directions are nearly perpendicular to the surface of said soft magnetic core;
- a core housing portion having a concave shape to receive said ring-shaped soft magnetic core;
- and
- a coil conductor arranged to extend through the hole in the ring-shaped soft magnetic core;
- wherein said core housing portion has an open portion with a gap that is slightly smaller than the outside diameter of said ring-shaped soft magnetic core and has elasticity in order to insert said ring-shaped soft magnetic core into said core housing portion, said core holder is made of a hard magnetic material magnetized in a direction nearly perpendicular to the surface of said ring-shaped soft magnetic core.
Dependencies are inferred from the claim text.