WIRELESS IC TAG, READER-WRITER, AND INFORMATION PROCESSING SYSTEM

• US 20120086556A1
• Filed: 12/19/2011
• Published: 04/12/2012
• Est. Priority Date: 11/04/2009
• Status: Active Grant

• Current Assignee: Murata Manufacturing Co Limited
• Original Assignee: Murata Manufacturing Co Limited
• Inventors: IKEMOTO, Nobuo
• Granted Patent: US 9,178,279 B2
• Time in Patent Office: Days
• US Class Current: 340/10.1
• 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. A wireless IC tag comprising:

a wireless IC chip; and

at least two coil-shaped antennas;

wherein

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; and

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

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 1, 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.

10. An information processing system comprising:

the wireless IC tag according to claim 1; and

a reader-writer;

wherein

the reader-writer is arranged to process information on the wireless IC tag.

11. The information processing system according to claim 10, wherein the reader-writer includes a loop antenna having a size substantially equal to a size of the first and second coil-shaped antennas of the wireless IC tag.

12. The information processing system according to claim 11, wherein the reader-writer is the reader-writer according to claim 9.

13. The information processing system according to claim 11, wherein the reader-writer includes a matching circuit provided in the loop antenna of the reader-writer.

9. A reader-writer comprising:

an antenna; and

an information processing portion;

wherein

the antenna includes a first coil-shaped antenna portion and a second coil-shaped antenna portion;

a first end of each of the first and second coil-shaped antenna portions is electrically connected to the information processing portion, and second ends of the first and second coil-shaped antenna portions are electrically connected to each other; and

winding axes of the first and second coil-shaped antenna portions are arranged at different positions and the first and second coil-shaped antenna portions have the same winding direction.