ANTENNA DEVICE AND ELECTRONIC APPLIANCE

• US 20150325918A1
• Filed: 07/20/2015
• Published: 11/12/2015
• Est. Priority Date: 12/26/2013
• Status: Active Grant

• Current Assignee: Murata Manufacturing Co Limited
• Original Assignee: Murata Manufacturing Co Limited
• Inventors: ITO, Hiromitsu
• Granted Patent: US 9,705,208 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: H01Q 1/24 with receiving set
• CPC Class Codes: H01Q 1/243 with built-in antennas
• CPC Class Codes: H01Q 1/50 Structural association of antennas with earthing switches, lead-in devices or lightning protectors
• CPC Class Codes: H01Q 1/521 reducing the coupling between adjacent antennas
• CPC Class Codes: H01Q 21/0006 Particular feeding systems
• CPC Class Codes: H01Q 21/06 Arrays of individually energised antenna units similarly polarised and spaced apart
• CPC Class Codes: H01Q 21/24 Combinations of antenna units polarised in different directions for transmitting or receiving circularly and elliptically polarised waves or waves linearly polarised in any direction circularly polarised patch antennas H01Q9/0428; circularly polarised horns H01Q13/0241; cross-polarised horns H01Q13/0258; polarisation converters H01Q15/242; cross-polarised rear feeds H01Q19/136; crossed polarisation dual antenna H01Q25/001
• CPC Class Codes: H01Q 21/28 Combinations of substantially independent non-interacting antenna units or systems multiple beam H01Q25/00
• CPC Class Codes: H01Q 21/29 Combinations of different interacting antenna units for giving a desired directional characteristic H01Q25/00 takes precedence
• 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: H04M 1/026 Details of the structure or mounting of specific components
• CPC Class Codes: H04M 2250/04 including near field communication means, e.g. RFID

Abstract

An antenna device includes coil antennas each including a coil conductor wound around a winding axis and a planar conductor that includes at least one edge and that is superposed with at least a portion of each of the coil antennas when viewed in plan. Winding axes of the plurality of coil antennas are parallel or substantially parallel to each other and so as to extend along a surface of the planar conductor, first coil opening ends of coil openings of the coil antennas in a direction in which the winding axes extend are contiguous with the edge and the coil antennas are connected such that magnetic fields generated by the coil antennas are in phase with each other. When W represents a width of the planar conductor, A represents a central spacing of the coil antennas and B represents a distance from a center of a coil antenna to a side of the planar conductor, A≦( 3/10)W.

Claims

1. An antenna device comprising:

a plurality of coil antennas each including a coil conductor wound around a winding axis; and

a planar conductor that includes at least one edge and that is superposed with at least a portion of each of the coil antennas when viewed in plan;

wherein

winding axes of the plurality of coil antennas are parallel or substantially parallel to each other and extend along a surface of the planar conductor, first coil opening ends of coil openings of the coil antennas in a direction in which the winding axes extend are contiguous with the edge, and the coil antennas are connected such that magnetic fluxes generated by the coil antennas are in phase with each other; and

when W represents a width of the planar conductor at a line that passes along second coil opening ends of the plurality of coil antennas on a side opposite to the first coil opening ends and extends in a direction perpendicular or substantially perpendicular to the winding axes and A represents a central spacing of adjacent coil antennas among the plurality of coil antennas, A≦

( 3/10)W.

2. The antenna device according to claim 1, wherein

a number of the plurality of coil antennas located at the one edge is N, where N is an integer of 2 or more;

and

B represents a distance from a center of a coil antenna at one end in a direction in which the N coil antennas are arranged to a side of the planar conductor along the line, (W−

A(N−

1))/2≦

B≦

W.

3. The antenna device according to claim 1, wherein

the plurality of coil antennas each include a magnetic substance;

and

the plurality of coil antennas are spaced apart from each other.

4. The antenna device according to claim 1, wherein a length of the coil antennas in a direction extending along the edge when viewed in plan is smaller than a length of the coil antennas in a direction perpendicular or substantially perpendicular to the edge.

5. The antenna device according to claim 1, wherein the first coil opening ends of the coil antennas are arranged at positions protruding farther toward the outside than the edge of the planar conductor.

6. The antenna device according to claim 1, further comprising a feeder circuit, wherein coil conductors of at least two coil antennas among the plurality of coil antennas are connected in series with the feeder circuit.

7. The antenna device according to claim 1, further comprising a feeder circuit, wherein coil conductors of at least two of the plurality of coil antennas are connected in parallel with the feeder circuit.

8. The antenna device according to claim 1, wherein at least one of the plurality of coil antennas includes a multilayer body including non-magnetic layers and magnetic layers.

9. The antenna device according to claim 8, wherein the multilayer body includes line-shaped electrodes and via-hole electrodes.

10. The antenna device according to claim 1, wherein at least two of the plurality of coil antennas are connected in series.

11. The antenna device according to claim 1, wherein at least two of the plurality of coil antennas are connected in parallel.

12. The antenna device according to claim 6, wherein the feeder circuit includes a reactance element configured to provide impedance matching and resonant frequency setting of the at least two coil antennas.

13. The antenna device according to claim 7, wherein the feeder circuit includes a reactance element configured to provide impedance matching and resonant frequency setting of the at least two coil antennas.

14. The antenna device according to claim 1, wherein the plurality of coil antennas includes at least three coil antennas arranged such that first coil opening ends thereof are contiguous with the edge of the planar conductor.

15. The antenna device according to claim 1, wherein the plurality of coil antennas includes at least four coil antennas arranged such that first coil opening ends thereof are contiguous with the edge of the planar conductor.

16. The antenna device according to claim 14, wherein the first coil opening ends of at least two of the at least four coil antennas are contiguous with a second edge of the planar conductor.

17. The antenna device according to claim 14, wherein the at least four coil antennas are arranged unevenly toward one corner of the planar conductor along two adjacent edges of the planar conductor.

18. An electronic appliance comprising:

the antenna device according to claim 1;

wherein

the coil antennas and the planar conductor are provided inside a casing.

19. The electronic appliance according to claim 18, wherein the electronic appliance is an RF device.

20. The electronic appliance according to claim 18, wherein the electronic appliance is one of a phone, a computer, a wearable terminal, a game console, a camera, and an RFID device.