Antenna device and wireless communication device

• US 9,692,128 B2
• Filed: 02/03/2014
• Issued: 06/27/2017
• Est. Priority Date: 02/24/2012
• Status: Active Grant

• Current Assignee: Murata Manufacturing Co Limited
• Original Assignee: Murata Manufacturing Co Limited
• Inventors: Kato, Noboru, Ozawa, Masahiro, Miura, Teppei
• Primary Examiner(s): Karacsony, Robert
• Application Number:
  US14/171,004
• Publication Number:
  US 20140145906A1
• Time in Patent Office: 1,240 Days
• Field of Search: None
• CPC Class Codes: H01L 2224/16225 the item being non-metallic, e.g. insulating substrate with or without metallisation
• CPC Class Codes: H01L 2924/19105 in a side-by-side arrangement on a common die mounting substrate
• 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 21/28 Combinations of substantially independent non-interacting antenna units or systems multiple beam H01Q25/00
• 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

Abstract

An antenna device includes a first coil antenna and a second coil antenna. The first coil antenna includes a coil conductor having a rectangular or substantially rectangular spiral shape and located on a non-magnetic insulating base member. The second coil antenna includes two coil conductors located on a non-magnetic insulating base member. The two coil conductors are disposed and wound such that loops of a magnetic field that is generated by applying a current to the two coil conductors are perpendicular or substantially perpendicular to a coil axis of the coil conductors.

Claims

1. An antenna device comprising:

a first coil antenna; and

a second coil antenna that is disposed in a vicinity of the first coil antenna;

wherein

the first coil antenna includes one coil conductor;

the second coil antenna includes two coil conductors wound such that a magnetic field that is generated by the two coil conductors defines a closed magnetic circuit;

the two coil conductors of the second coil antenna are wound in a spiral shape when seen in a plan view from a direction of a winding axis of the coil conductor of the first coil antenna;

the closed magnetic circuit is disposed in an area inside the coil conductor of the first coil antenna or is disposed in an area outside the coil conductor of the first coil antenna;

the first coil antenna is configured for use in a first communication system; and

the second coil antenna is configured for use in a second communication system.

2. The antenna device according to claim 1, wherein the first communication system and the second communication system are communication systems that use a same frequency band.

3. The antenna device according to claim 1, wherein the first coil antenna and the second coil antenna are arranged such that the winding axis of the coil conductor of the first coil antenna is present in a plane that includes the winding axes of the two coil conductors of the second coil antenna.

4. The antenna device according to claim 1, wherein a region in which the first coil antenna is located and a region in which the second coil antenna is located are at least partially superposed with each other when seen in plan view from winding axis directions of the winding axes of the two coil conductors of the second coil antenna and the winding axis of the coil conductor of the first coil antenna.

5. The antenna device according to claim 1, wherein

the first coil antenna and the second coil antenna are positioned adjacent to each other such that a coil surface of each of the first and second coil antennas are positioned in a same plane;

and

the first coil antenna and the second coil antenna are used in one communication system.

6. The antenna device according to claim 5, wherein the coil conductor of the first coil antenna is interposed between the two coil conductors of the second coil antenna.

7. The antenna device according to claim 1, further comprising a power supply coil that is configured to be in at least a magnetic field coupling relationship with at least one of the first coil antenna and the second coil antenna.

8. A wireless communication device comprising:

an antenna device that includes a first coil antenna and a second coil antenna disposed in a vicinity of the first coil antenna;

wherein

the first coil antenna includes one coil conductor;

the second coil antenna includes two coil conductors wound such that a magnetic field that is generated by the two coil conductors defines a closed magnetic circuit;

the two coil conductors of the second coil antenna are wound in a spiral shape when seen in a plan view from a direction of a winding axis of the coil conductor of the first coil antenna;

the closed magnetic circuit is disposed in an area inside the coil conductor of the first coil antenna or is disposed in an area outside the coil conductor of the first coil antenna;

the first coil antenna is configured for use in a first communication system; and

the second coil antenna is configured for use in a second communication system.

9. The wireless communication device according to claim 8, wherein

the antenna device is compatible with the first communication system and the second communication system;

and

the first coil antenna and the second coil antenna are allocated depending on a length of the longest communication range required for the first communication system and the second communication system.

10. The wireless communication device according to claim 8, wherein

the first coil antenna and the second coil antenna are positioned adjacent to each other such that coil surfaces of the first and second coil antennas are positioned in a same plane;

and

the first coil antenna and the second coil antenna are used in one communication system.

11. The wireless communication device according to claim 10, further comprising:

a common power supply circuit that supplies power to the first coil antenna and the second coil antenna; and

a switch that selectively performs switching of a signal path between the first coil antenna and the second coil antenna and the power supply circuit.

12. The wireless communication device according to claim 8, further comprising a power supply coil that is configured to be in at least a magnetic field coupling relationship with at least one of the first coil antenna and the second coil antenna.

13. The wireless communication device according to claim 8, wherein the first communication system and the second communication system are communication systems that use a same frequency band.

14. The wireless communication device according to claim 8, wherein the first coil antenna and the second coil antenna are arranged such that the winding axis of the coil conductor of the first coil antenna is present in a plane that includes the winding axes of the two coil conductors of the second coil antenna.

15. The wireless communication device according to claim 8, wherein a region in which the first coil antenna is located and a region in which the second coil antenna is located are at least partially superposed with each other when seen in plan view from winding axis directions of the winding axes of the two coil conductors of the second coil antenna and the winding axis of the coil conductor of the first coil antenna.

16. The wireless communication device according to claim 8, wherein

the first coil antenna and the second coil antenna are positioned adjacent to each other such that a coil surface of each of the first and second coil antennas are positioned in a same plane;

and

the first coil antenna and the second coil antenna are used in one communication system.

17. The wireless communication device according to claim 16, wherein the coil conductor of the first coil antenna is interposed between the two coil conductors of the second coil antenna.