Radio communication device and radio communication terminal

• US 8,602,310 B2
• Filed: 08/31/2012
• Issued: 12/10/2013
• Est. Priority Date: 03/03/2010
• Status: Active Grant

• Current Assignee: Murata Manufacturing Co Limited
• Original Assignee: Murata Manufacturing Co Limited
• Inventors: Kato, Noboru, Murayama, Hiromi
• Primary Examiner(s): Frech, Karl D
• Application Number:
  US13/600,256
• Publication Number:
  US 20120325915A1
• Time in Patent Office: 466 Days
• Field of Search: 235/487, 235/492
• US Class Current: 235/487
• CPC Class Codes: H01L 2224/16225 the item being non-metallic, e.g. insulating substrate with or without metallisation
• 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 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: H02J 50/20 using microwaves or radio frequency waves
• CPC Class Codes: H04B 5/26 using coils
• CPC Class Codes: H04B 5/79 for data transfer in combination with power transfer

Abstract

A radio communication device includes a radio frequency IC chip configured to process a radio signal, a feeding circuit board that is coupled to the radio frequency IC chip and includes a loop electrode including coil patterns having a predetermined winding width, and an antenna pattern that is magnetically coupled to the loop electrode. The feeding circuit board is arranged so that, in plan view, a first region of the loop electrode in which the coil patterns extend in a first direction overlaps the antenna pattern and a second region of the loop electrode in which the coil patterns extend in a second direction opposite to the first direction do not overlap the antenna pattern. The first direction and a line length direction of the antenna pattern are the same or substantially the same.

Claims

1. A radio communication device comprising:

a radio frequency IC configured to process a radio signal;

a feeding circuit connected to the radio frequency IC and including a loop electrode including a coil pattern with a predetermined winding width; and

an antenna pattern magnetically coupled to the loop electrode;

wherein

the feeding circuit is arranged so that, in plan view as seen from a coil axis direction of the coil pattern, a first region of the loop electrode in which the coil pattern extends in a first direction overlaps the antenna pattern and a second region of the loop electrode in which the coil pattern extends in a second direction opposite to the first direction does not overlap the antenna pattern;

the first direction and a line length direction of the antenna pattern are the same or substantially the same; and

no radio frequency IC is directly connected or coupled to the antenna pattern.

2. The radio communication device according to claim 1, wherein the coil pattern includes a plurality of winding turns in a common plane within the predetermined winding width.

3. The radio communication device according to claim 1, wherein

the feeding circuit includes a feeder circuit board which is a multilayer substrate including a plurality of layers;

and

the coil pattern includes a plurality of coil patterns provided on at least two of a plurality of layers and the plurality of coil patterns on the at least two of the plurality of layers are connected via interlayer conductors.

4. The radio communication device according to claim 1, wherein the coil pattern of the feeding circuit is arranged so that, in plan view as seen from the coil axis direction, the first region overlaps the antenna pattern throughout a width of the first region.

5. The radio communication device according to claim 4, wherein a line width of the antenna pattern is greater than the predetermined winding width of the coil pattern.

6. The radio communication device according to claim 1, wherein the coil pattern of the feeding circuit is arranged so that, in plan view as seen from the coil axis direction, an opening of the coil pattern does not overlap the antenna pattern.

7. The radio communication device according to claim 1, wherein the loop electrode has a rectangular or substantially rectangular shape in plan view as seen from the coil axis direction.

8. The radio communication device according to claim 1, wherein the antenna pattern includes a plurality of winding turns in a common plane and has a coil shape.

9. The radio communication device according to claim 8, wherein the coil pattern of the feeding circuit is arranged so that, in plan view as seen from the coil axis direction, a width of the first region does not straddle each of the plurality of winding turns of the antenna pattern.

10. The radio communication device according to claim 8, wherein the feeding circuit is arranged so that the coil pattern of the feeding circuit faces a corner of the antenna pattern, and adjacent two sides of the loop electrode overlap the antenna pattern in plan view as seen from the coil axis direction.

11. A radio communication terminal comprising a radio communication device including:

a radio frequency IC configured to process a radio signal;

a feeding circuit connected to the radio frequency IC and including a loop electrode including a coil pattern with a predetermined winding width; and

an antenna pattern magnetically coupled to the loop electrode;

wherein

the feeding circuit is arranged so that, in plan view from a coil axis direction of the coil pattern, a first region of the loop electrode in which the coil pattern extends in a first direction overlaps the antenna pattern and a second region of the loop electrode in which the coil pattern extends in a second direction opposite to the first direction does not overlap the antenna pattern;

the first direction and a line length direction of the antenna pattern are the same or substantially the same; and

no radio frequency IC is directly connected or coupled to the antenna pattern.

12. The radio communication terminal according to claim 11, wherein the coil pattern includes a plurality of winding turns in a common plane within the predetermined winding width.

13. The radio communication terminal according to claim 11, wherein

the feeding circuit includes a feeder circuit board which is a multilayer substrate including a plurality of layers;

and

the coil pattern includes a plurality of coil patterns provided on at least two of a plurality of layers and the plurality of coil patterns on the at least two of the plurality of layers are connected via interlayer conductors.

14. The radio communication terminal according to claim 11, wherein the coil pattern of the feeding circuit is arranged so that, in plan view as seen from the coil axis direction, the first region overlaps the antenna pattern throughout a width of the first region.

15. The radio communication terminal according to claim 14, wherein a line width of the antenna pattern is greater than the predetermined winding width of the coil pattern.

16. The radio communication terminal according to claim 11, wherein the coil pattern of the feeding circuit is arranged so that, in plan view as seen from the coil axis direction, an opening of the coil pattern does not overlap the antenna pattern.

17. The radio communication terminal according to claim 11, wherein the loop electrode has a rectangular or substantially rectangular shape in plan view as seen from the coil axis direction.

18. The radio communication terminal according to claim 11, wherein the antenna pattern includes a plurality of winding turns in a common plane and has a coil shape.

19. The radio communication terminal according to claim 18, wherein the coil pattern of the feeding circuit is arranged so that, in plan view as seen from the coil axis direction, a width of the first region does not straddle each of the plurality of winding turns of the antenna pattern.

20. The radio communication terminal according to claim 18, wherein the feeding circuit is arranged so that the coil pattern of the feeding circuit faces a corner of the antenna pattern, and adjacent two sides of the loop electrode overlap the antenna pattern in plan view as seen from the coil axis direction.