Wireless IC device component and wireless IC device

• US 8,690,070 B2
• Filed: 03/12/2013
• Issued: 04/08/2014
• Est. Priority Date: 04/14/2009
• Status: Active Grant

• Current Assignee: Murata Manufacturing Co Limited
• Original Assignee: Murata Manufacturing Co Limited
• Inventors: Kato, Noburo, Dokai, Yuya
• Primary Examiner(s): St Cyr, Daniel
• Application Number:
  US13/794,929
• Publication Number:
  US 20130200163A1
• Time in Patent Office: 392 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 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 define an annular electrode including an opening portion defined by an inner edge of the annular electrode; and

a radiation plate coupled to the coupling electrode;

wherein

a main surface of the annular electrode is parallel or substantially parallel to a main surface of the radiation plate;

each of the pair of ends of the annular electrode is overlapped with a portion of the radiation plate in a plan view and coupled to the portion of the radiation plate via a capacitive coupling; and

a majority of the opening portion is not overlapped with the radiation plate in the plan view.

2. The wireless IC device according to claim 1, wherein the annular electrode is coupled to the radiation plate via a magnetic coupling.

3. The wireless IC device according to claim 2, wherein a first group of signals of a plurality of signals are externally radiated from the coupling electrode via a magnetic field, and a second group of signals of the plurality of signals are externally radiated from the radiation plate via an electric field.

4. The wireless IC device according to claim 3, wherein a resonant frequency of the coupling electrode is lower than a resonant frequency of the radiation plate.

5. The wireless IC device according to claim 1, wherein the at least one coupling portion of the coupling electrode is not overlapped with the radiation plate in the plan view.

6. The wireless IC device according to claim 1, wherein the pair of ends of the coupling electrode is coupled to a central portion of the radiation plate.

7. The wireless IC device according to claim 1, wherein the radiation plate is defined by a portion of an article to which the wireless IC device is attached.