Wireless IC tag, reader-writer, and information processing system

• US 9,178,279 B2
• Filed: 12/19/2011
• Issued: 11/03/2015
• Est. Priority Date: 11/04/2009
• Status: Active Grant

• Current Assignee: Murata Manufacturing Co Limited
• Original Assignee: Murata Manufacturing Co Limited
• Inventors: Ikemoto, Nobuo
• Primary Examiner(s): SYED, NABIL H
• Application Number:
  US13/329,354
• Publication Number:
  US 20120086556A1
• Time in Patent Office: 1,415 Days
• Field of Search: 340/10.1, 340/10.2, 340/10.3, 340/10.4, 340/572.1, 340/572.3, 340/572.7
• US Class Current: 1/1
• CPC Class Codes: G01S 13/751 wherein the responder or reflector radiates a coded signal
• CPC Class Codes: G06K 19/07749 the record carrier being capable of non-contact communication, e.g. constructional details of the antenna of a non-contact smart card
• CPC Class Codes: G06K 19/07779 the inductive antenna being a coil
• CPC Class Codes: G06K 19/07783 the coil being planar
• CPC Class Codes: G06K 19/07784 the inductive antenna consisting of a plurality of coils stacked on top of one another
• CPC Class Codes: H01Q 1/2216 used in interrogator/reader equipment
• 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 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: H04B 5/263 Multiple coils at either side
• CPC Class Codes: H04B 5/43 Antennas
• CPC Class Codes: H04B 5/77 for interrogation
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

A wireless IC tag includes a wireless IC chip and two coil-shaped antennas. One end of each of the coil-shaped antennas is electrically connected to the wireless IC chip, and the other ends of the coil-shaped antennas are electrically connected to each other. The winding axes of the coil-shaped antennas are arranged at different positions, and the coil-shaped antennas have the same winding direction. A reader-writer includes an antenna connected to an information processing circuit. The antenna is electromagnetically coupled to the coil-shaped antennas for communication.

Claims

1. An information processing system for performing wireless communication comprising:

a wireless IC tag; and

a reader-writer;

wherein

the wireless tag includes a wireless IC chip and at least two coil-shaped antennas;

a first end of each of the at least two coil-shaped antennas is electrically connected to the wireless IC chip and second ends of the at least two coil-shaped antennas are electrically connected to each other;

winding axes of the at least two coil-shaped antennas are arranged at different positions and the at least two coil-shaped antennas have a same winding direction;

the reader-writer includes a reader-writer antenna and an information processing portion;

the reader-writer antenna has a size substantially equal to a size of the at least two coil-shaped antennas of the wireless IC tag;

a first end of the reader-writer antenna is electrically connected to a first end of the information processing portion, and a second end of the reader-writer antenna is electrically connected to a second end of the information processing portion;

the at least two coil-shaped antennas of the wireless IC tag are wound and connected to each other so as to produce in-phase magnetic fields;

the reader-writer antenna and the at least two coil shaped antennas of the wireless IC tag are overlaid directly on top of each other during communication; and

the reader-writer antenna has a diameter substantially equal to a sum of diameters of the at least two coil-shaped antennas.

2. The wireless IC tag according to claim 1, wherein

each of the at least two coil-shaped antennas includes a plurality of coil conductors stacked in a substrate.

3. The wireless IC tag according to claim 2, wherein

the plurality of coil conductors are arranged so that the plurality of coil conductors are overlaid on one another in the direction of the winding axes in a plan view.

4. The wireless IC tag according to claim 2, wherein the wireless IC chip is disposed on the substrate and is covered with a sealing member.

5. The wireless IC tag according to claim 2, wherein a ferrite layer is provided on at least one of a top surface and a bottom surface of the substrate.

6. The wireless IC tag according to claim 2, wherein the at least two coil-shaped antennas are provided in the substrate and an outer electrode is provided on the substrate.

7. The wireless IC tag according to claim 6, wherein the at least two coil-shaped antennas are electrically connected to the outer electrode.

8. The wireless IC tag according to claim 6, further comprising at least one boost antenna arranged to oppose the outer electrode.

9. The information processing system according to claim 1, wherein the reader-writer includes a matching circuit provided between the reader-writer antenna and the information processing portion.

10. The information processing system according to claim 1, wherein the reader-writer antenna includes a loop-shaped magnetic field antenna including multiple turns.

11. The information processing system according to claim 1, wherein the reader-writer antenna includes a first coil-shaped antenna portion and a second coil-shaped antenna portion.

12. The information processing system according to claim 11, wherein each of the first coil-shaped antenna portion and the second coil-shaped antenna portion of the reader-writer antenna include a loop-shaped magnetic field antenna including multiple turns.

13. The information processing system according to claim 1, wherein the reader-writer includes a grip portion and an antenna head which is a pen-shaped head including the reader-writer antenna.