Wireless IC device component and wireless IC device

• US 8,418,928 B2
• Filed: 09/23/2011
• Issued: 04/16/2013
• Est. Priority Date: 04/14/2009
• Status: Active Grant

• Current Assignee: Murata Manufacturing Co Limited
• Original Assignee: Murata Manufacturing Co Limited
• Inventors: Kato, Noboru, Dokai, Yuya
• Primary Examiner(s): St. Cyr, Daniel
• Application Number:
  US13/241,823
• Publication Number:
  US 20120006904A1
• Time in Patent Office: 571 Days
• Field of Search: 235/487, 235/492
• US Class Current: 235/492
• 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 19/07754 the connection being galvanic
• CPC Class Codes: G06K 19/07756 the connection being non-galvanic, e.g. capacitive
• 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 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 9/26 with folded element or elements, the folded parts being spaced apart a small fraction of operating wavelength resonant loop antennas H01Q7/00
• CPC Class Codes: H01Q 9/285 Planar dipole H01Q9/065 takes precedence; patch antenna H01Q9/0407

Abstract

A wireless IC device includes a wireless IC chip, a coupling electrode, and a radiation plate. The coupling electrode includes coupling portions arranged to be coupled to the wireless IC chip and a pair of opposing ends. The pair of opposing ends are capacitively coupled to each other and oppose the radiation plate to be coupled to the radiation plate. The wireless IC chip uses the radiation plate as an antenna to transmit and receive signals having certain frequencies to and from an RFID system.

Claims

1. A wireless IC device component comprising:

a wireless IC; and

a coupling electrode including at least one coupling portion arranged to be coupled to the wireless IC directly or via a feed circuit and a pair of ends arranged opposite to each other so as to be capacitively coupled to each other and to define an annular electrode;

wherein

the coupling electrode is arranged to be coupled to a radiation plate;

each of the pair of ends of the coupling electrode includes an inner side and an outer side, the inner side being arranged to be farther from the radiation plate than the outer side;

the inner side of one of the pair of ends of the coupling electrode is opposed to the outer side of the other one of the pair of ends of the coupling electrode such that the inner side of the one of the pair of ends of the coupling electrode is capacitively coupled to the outer side of the other one of the pair of ends of the coupling electrode; and

the other one of the pair of ends of the coupling electrode is disposed between the one of the pair of ends of the coupling electrode and the radiation plate.

2. The wireless IC device component according to claim 1, wherein the coupling electrode includes a longitudinal dimension and a latitudinal dimension in a plan view and the at least one coupling portion includes at least two coupling portions that are opposed to each other along the latitudinal dimension.

3. The wireless IC device component according to claim 1, wherein the at least one coupling portion is arranged at a position different from positions of the pair of ends in a plan view.

4. The wireless IC device component according to claim 1, wherein the coupling electrode is provided on a first main surface of a dielectric substrate and the pair of opposing ends are provided on a second main surface of the dielectric substrate opposite to the first main surface of the dielectric substrate.

5. A wireless IC device comprising:

a wireless IC;

a coupling electrode including at least one coupling portion arranged to be coupled to the wireless IC directly or via a feed circuit and a pair of ends arranged opposite to each other so as to be capacitively coupled to each other and to define an annular electrode; and

a radiation plate coupled to the coupling electrode;

wherein

each of the pair of ends of the coupling electrode includes an inner side and an outer side, the inner side being arranged farther from the radiation plate than the outer side; and

the inner side of one of the pair of ends of the coupling electrode is opposed to the outer side of the other one of the pair of ends of the coupling electrode such that the inner side of the one of the pair of ends of the coupling electrode is capacitively coupled to the outer side of the other one of the pair of ends of the coupling electrode;

the outer side of the one of the pair of ends of the coupling electrode is disposed between the radiation plate and the capacitively coupled inner side of the one of the pair of ends of the coupling electrode and outer side of the other one of the pair of ends of the coupling electrode; and

the other one of the pair of ends of the coupling electrode is disposed between the one of the pair of ends of the coupling electrode and the radiation plate.

6. The wireless IC device according to claim 5, wherein the coupling electrode includes a longitudinal dimension and a latitudinal dimension in a plan view and the at least one coupling portion includes at least two coupling portions that are opposed to each other along the latitudinal dimension.

7. The wireless IC device according to claim 5, wherein the at least one coupling portion is arranged at a position different from positions of the pair of ends in a plan view.

8. The wireless IC device according to claim 5, wherein the coupling electrode is provided on a first main surface of a dielectric substrate and the pair of ends are provided on a second main surface of the dielectric substrate opposite to the first main surface of the dielectric substrate.

9. The wireless IC device according to claim 5, wherein a loop surface of the coupling electrode is arranged so as to be perpendicular or substantially perpendicular to the radiation plate.

10. The wireless IC device according to claim 5, wherein the wireless IC is mounted on or in a feed circuit board and the feed circuit board includes at least one of a resonant circuit and a matching circuit.

11. The wireless IC device according to claim 10, wherein a resonant frequency of the resonant circuit substantially corresponds to a frequency of a signal transmitted or received via the radiation plate.

12. The wireless IC device according to claim 10, wherein the at least one coupling electrode is provided on or in the feed circuit board.

13. The wireless IC device according to claim 10, wherein the feed circuit board is a flexible board.

14. The wireless IC device according to claim 5, wherein the radiation plate is defined by a portion of an article.