Antenna having structure for multi-angled reception and mobile terminal including the antenna

• US 8,718,727 B2
• Filed: 04/23/2012
• Issued: 05/06/2014
• Est. Priority Date: 12/24/2009
• Status: Active Grant

• Current Assignee: Murata Manufacturing Co Limited
• Original Assignee: Murata Manufacturing Co Limited
• Inventors: Kubo, Hiroyuki, Ito, Hiromitsu, Yosui, Kuniaki
• Primary Examiner(s): MIZRAHI, DIANE D
• Application Number:
  US13/452,972
• Publication Number:
  US 20120208606A1
• Time in Patent Office: 743 Days
• Field of Search: 455/575.7
• US Class Current: 455/575.7
• CPC Class Codes: G06K 19/07779 the inductive antenna being a coil
• CPC Class Codes: H01Q 1/2216 used in interrogator/reader equipment
• CPC Class Codes: H01Q 1/242 specially adapted for hand-held use
• CPC Class Codes: H01Q 7/06 with core of ferromagnetic material H01Q7/02 takes precedence

Abstract

An antenna that suppresses deterioration of communication performance depending on an angle with respect to a reading surface of a reader/writer includes a rectangular spiral coil conductor provided on a flexible substrate. The flexible substrate includes an aperture in a winding center portion of the coil conductor. A magnetic sheet penetrates the aperture of the flexible substrate. An antenna coil is provided near an end of a circuit board. A first conductor portion and a second conductor portion of the coil conductor are provided at positions opposing each other across the aperture. A portion of the magnetic sheet close to the second conductor portion is bent in a direction to get close to the circuit board.

Claims

1. An antenna comprising:

a mobile antenna, said mobile antenna comprising;

an antenna coil including a plate-shaped magnetic sheet and a coil conductor on a flexible substrate including an aperture and wound on the magnetic sheet; and

a conductive plane provided adjacent to the antenna coil, wherein

a first principal surface of the magnetic sheet faces toward an upper surface of the conductive plane;

the antenna coil is located adjacent an end of the conductive plane;

a first conductor portion of the coil conductor adjacent to the first principal surface of the magnetic sheet and a second conductor portion of the coil conductor adjacent to a second principal surface of the magnetic sheet are arranged to not overlap in a thickness direction of the magnetic sheet;

the second conductor portion is located closer to an end of the conductive plane than the first conductor portion and opposing each other across the aperture; and

a portion of the magnetic sheet adjacent to the second conductor portion and including the second conductor portion of the coil conductor is bent toward the conductive plane.

2. The antenna according to claim 1, wherein the coil conductor is provided in a spiral configuration on one surface of the flexible substrate, the aperture is at a position where the coil conductor is provided, and the magnetic sheet is inserted in the aperture.

3. The antenna according to claim 1, wherein the magnetic sheet is sheet-shaped and includes a mixture of magnetic powder and a resin material, or is sheet-shaped and includes a sintered magnetic material divided into a plurality of small pieces.

4. The antenna according to claim 1, wherein a portion of the magnetic sheet adjacent to the end of the conductive plane is wider than the other portion.

5. The antenna according to claim 2, wherein the antenna coil is provided on a support base that maintains shapes of the magnetic sheet and the flexible substrate.

6. The antenna according to claim 1, wherein the antenna coil is mounted on a circuit board including the conductive plane.

7. A mobile terminal comprising:

an antenna including;

an antenna coil including a plate-shaped magnetic sheet and a coil conductor on a flexible substrate including an aperture and wound on the magnetic sheet;

a planar conductor provided on the first principal surface of the magnetic sheet; and

a conductive plane provided adjacent to the antenna coil;

a housing including the antenna; and

a communication circuit stored in the housing so to perform communication using the antenna;

wherein

a first principal surface of the magnetic sheet faces toward an upper surface of the conductive plane;

the antenna coil is located adjacent an end of the conductive plane;

a first conductor portion of the coil conductor adjacent to the first principal surface of the magnetic sheet and a second conductor portion of the coil conductor adjacent to a second principal surface of the magnetic sheet are arranged to not overlap in a thickness direction of the magnetic sheet;

the second conductor portion is located closer to an end of the conductive plane than the first conductor portion and opposing each other across the aperture; and

a portion of the magnetic sheet adjacent to the second conductor portion and including the second conductor portion of the coil conductor is bent toward the conductive plane.