Antenna device and communication terminal apparatus

• US 9,391,369 B2
• Filed: 12/28/2012
• Issued: 07/12/2016
• Est. Priority Date: 09/07/2010
• Status: Active Grant

• Current Assignee: Murata Manufacturing Co Limited
• Original Assignee: Murata Manufacturing Co Limited
• Inventors: Miura, Teppei, Sasaki, Jun, Kubo, Hiroyuki, Taniguchi, Katsumi, Kato, Noboru, Ozawa, Masahiro, Ishino, Satoshi
• Primary Examiner(s): Levi, Dameon E
• Assistant Examiner(s): MAGALLANES, RICARDO I
• Application Number:
  US13/729,377
• Publication Number:
  US 20130181876A1
• Time in Patent Office: 1,292 Days
• Field of Search: 343/895, 343/700.MS, 343/788, 343/867
• US Class Current: 1/1
• CPC Class Codes: G06K 7/10316 using at least one antenna particularly designed for interrogating the wireless record carriers antennas in general H01Q1/22
• CPC Class Codes: G06K 7/10336 the antenna being of the near field type, inductive coil
• CPC Class Codes: H01Q 1/2208 associated with components used in interrogation type services, i.e. in systems for information exchange between an interrogator/reader and a tag/transponder, e.g. in Radio Frequency Identification [RFID] systems methods or arrangements for sensing record carriers, e.g. for reading patterns G06K7/00; record carrier for use with machines and with at least a part designed to carry digital markings G06K19/00
• 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 1/243 with built-in antennas
• CPC Class Codes: H01Q 1/38 formed by a conductive layer on an insulating support patch antennas H01Q9/0407; microstrip dipole antennas H01Q9/065; microstrip slot antennas H01Q13/106; transmission line microstrip antennas H01Q13/206; manufacturing reflecting surfaces using insulating material for supporting the reflecting surface H01Q15/142
• CPC Class Codes: H01Q 21/293 one unit or more being an array of identical aerial elements adaptive arrays H01Q3/2605
• CPC Class Codes: H01Q 25/00 Antennas or antenna systems providing at least two radiating patterns arrangements for changing or varying the orientation or the shape of the directional pattern H01Q3/00
• CPC Class Codes: H01Q 7/00 Loop antennas with a substantially uniform current distribution around the loop and having a directional radiation pattern in a plane perpendicular to the plane of the loop
• 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

An antenna device that includes coil antennas each having a coil conductor wound around a winding axis and a planar conductor including a surface and an edge end portion, the surface extending along the winding axis of the coil conductor, the edge end portion being adjacent to a coil opening of the coil conductor. A current flowing through the coil conductor induces a current in the planar conductor, this current produces a magnetic flux in a direction normal to the planar conductor, and thus the planar conductor acts as a booster antenna. The antenna device has directivity in the direction normal to the planar conductor because the magnetic flux produced by the coil antennas and that produced by the planar conductor are combined. This enables the antenna device to occupy a small area while achieving a predetermined communication distance.

Claims

1. An antenna device comprising:

a planar base;

a first planar conductor disposed in the planar base;

a second planar conductor disposed in the planar base, such that the second planar conductor is adjacent to the first planar conductor in a plan view of the planar base; and

a coil antenna that includes a coil conductor wound along a winding axis and a magnetic body disposed at least inside a winding region of the coil conductor,

wherein the coil antenna includes first and second coil openings in the winding axis of the coil conductor that are disposed adjacent to respective edge portions of the first and second planar conductors, respectively,

wherein each of the first and second planar conductors includes a portion that does not overlap with the winding region of the coil conductor in a direction normal to the planar base,

wherein the winding axis of the coil conductor extends in a direction parallel to planar surfaces of the first and second planar conductors, and

wherein at least one of the first and second planar conductors is insulated from direct contact with the coil conductor.

2. The antenna device according to claim 1, wherein at least a portion of first and second end portions of the coil conductor overlap the first and second planar conductors, respectively, in a direction normal to the planar base.

3. The antenna device according to claim 1, wherein the planar base is a printed wiring board.

4. The antenna device according to claim 1, wherein both of the first and second planar conductors are insulated in terms of direct contact with the coil conductor.

5. The antenna device according to claim 1, wherein both of the first and second planar conductors are insulated from the coil conductor.

6. The antenna device according to claim 1, wherein both of the first and second planar conductors are disposed within the planar base, such that the first and second planar conductors do not contact a surface of the planar base.

7. An antenna device comprising:

a planar base;

a first planar conductor disposed in the planar base;

a second planar conductor disposed in the planar base, such that the second planar conductor is adjacent to the first planar conductor in a plan view of the planar base; and

a coil antenna that includes a coil conductor wound along a winding axis and a magnetic body disposed at least inside a winding region of the coil conductor,

wherein the coil antenna includes first and second coil openings in the winding axis of the coil conductor that are disposed adjacent to respective edge portions of the first and second planar conductors, respectively,

wherein each of the first and second planar conductors includes a portion that does not overlap with the winding region of the coil conductor in a direction normal to the planar base,

wherein the winding axis of the coil conductor extends in a direction parallel to planar surfaces of the first and second planar conductors, and

wherein the antenna device is a high frequency (HF) band device.

8. The antenna device according to claim 7, wherein at least a portion of first and second end portions of the coil conductor overlap the first and second planar conductors, respectively, in a direction normal to the planar base.

9. The antenna device according to claim 7, wherein the planar base is a printed wiring board.

10. The antenna device according to claim 7, wherein at least one of the first and second planar conductors is insulated in terms of direct contact with the coil conductor.

11. The antenna device according to claim 10, wherein both of the first and second planar conductors are insulated in terms of direct contact with the coil conductor.

12. The antenna device according to claim 7, wherein both of the first and second planar conductors are insulated from the coil conductor.

13. The antenna device according to claim 7, wherein both of the first and second planar conductors are disposed within the planar base, such that the first and second planar conductors do not contact a surface of the planar base.