Antenna coil to be mounted on a circuit board and antenna device

• US 8,928,547 B2
• Filed: 05/22/2013
• Issued: 01/06/2015
• Est. Priority Date: 07/07/2006
• Status: Expired due to Fees

• Current Assignee: Murata Manufacturing Co Limited
• Original Assignee: Murata Manufacturing Co Limited
• Inventors: Yosui, Kuniaki, Kubo, Hiroyuki, Ito, Hiromitsu
• Primary Examiner(s): DUONG, DIEU HIEN
• Application Number:
  US13/899,693
• Publication Number:
  US 20130249758A1
• Time in Patent Office: 594 Days
• Field of Search: 343/788, 343/787, 343/867
• US Class Current: 343/788
• CPC Class Codes: H01Q 1/2225 used in active tags, i.e. provided with its own power source or in passive tags, i.e. deriving power from RF signal
• CPC Class Codes: H01Q 7/06 with core of ferromagnetic material H01Q7/02 takes precedence
• CPC Class Codes: H01Q 7/08 Ferrite rod or like elongated core

Abstract

In an antenna coil including a first magnetic core, a second magnetic core, and a flexible board, coil conductors are provided on a surface of the flexible board. By winding the flexible board around the first magnetic core and the second magnetic core, a first coil portion is disposed around the first magnetic core, and a second coil portion is disposed around the second magnetic core. The winding direction of the second coil portion is opposite to that of the first coil portion. The first coil portion and the second coil portion are connected to define one coil as a whole.

Claims

1. An antenna coil for a mobile terminal comprising:

a magnetic core having a substantially flat plate shape;

a flexible insulating film including a plurality of conductors, all portions of each of the plurality of conductors are provided on only a single surface of the flexible insulating film such that no conductors or portions thereof are provided on any other surface of the flexible insulating film; and

a coil arranged around the magnetic core and defined by the plurality of conductors;

wherein

the flexible insulating film is provided on the magnetic core such that the plurality of conductors are arranged between the magnetic core and the flexible insulating film; and

the plurality of conductors provided on the flexible insulating film are not physically connected to one another on the flexible insulating film in a state in which the flexible insulating film is not provided on the magnetic core.

2. The antenna coil according to claim 1, wherein the flexible insulating film is a polyimide film or a glass epoxy film.

3. The antenna coil according to claim 1, wherein the magnetic core has a substantially rectangular shape.

4. The antenna coil according to claim 3, wherein the magnetic core is made of a ferrite material.