WIRELESS IC DEVICE

• US 20090002130A1
• Filed: 09/16/2008
• Published: 01/01/2009
• Est. Priority Date: 04/10/2006
• Status: Active Grant

• Current Assignee: Murata Manufacturing Co Limited
• Original Assignee: Murata Manufacturing Co Limited
• Inventors: KATO, Noboru
• Granted Patent: US 8,384,547 B2
• Time in Patent Office: Days
• US Class Current: 340/10.100
• 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 19/07786 the antenna being of the HF type, such as a dipole
• CPC Class Codes: H01Q 1/2208 associated with components used in interrogation type services, i.e. in systems for information exchange between an interrogator/reader and a tag/transponder, e.g. in Radio Frequency Identification [RFID] systems methods or arrangements for sensing record carriers, e.g. for reading patterns G06K7/00; record carrier for use with machines and with at least a part designed to carry digital markings G06K19/00
• CPC Class Codes: H01Q 1/38 formed by a conductive layer on an insulating support patch antennas H01Q9/0407; microstrip dipole antennas H01Q9/065; microstrip slot antennas H01Q13/106; transmission line microstrip antennas H01Q13/206; manufacturing reflecting surfaces using insulating material for supporting the reflecting surface H01Q15/142
• CPC Class Codes: H01Q 21/08 the units being spaced along or adjacent to a rectilinear path waveguide fed H01Q21/0037
• CPC Class Codes: H01Q 21/24 Combinations of antenna units polarised in different directions for transmitting or receiving circularly and elliptically polarised waves or waves linearly polarised in any direction circularly polarised patch antennas H01Q9/0428; circularly polarised horns H01Q13/0241; cross-polarised horns H01Q13/0258; polarisation converters H01Q15/242; cross-polarised rear feeds H01Q19/136; crossed polarisation dual antenna H01Q25/001
• CPC Class Codes: H01Q 23/00 Antennas with active circuits or circuit elements integrated within them or attached to them
• CPC Class Codes: H01Q 9/28 Conical, cylindrical, cage, strip, gauze, or like elements having an extended radiating surface; Elements comprising two conical surfaces having collinear axes and adjacent apices and fed by two-conductor transmission lines waveguide horns or mouths H01Q13/00; slot antennas H01Q13/00

Abstract

A wireless IC device includes a wireless IC chip having a power supply circuit including a resonant circuit having a predetermined resonant frequency and a radiation plate that externally radiates a transmission signal supplied from the power supply circuit and that supplies a reception signal externally transmitted to the power supply circuit. The radiation plate is connected to the power supply circuit via an electric field or the radiation plate is coupled to the power supply circuit via a magnetic field. The radiation plate is a two-surface-open type radiation plate including at least one radiation portion arranged to externally exchange a transmission-reception signal and a power supply portion arranged to exchange a transmission-reception signal with the power supply circuit.

Claims

1. A wireless IC device comprising:

a wireless IC chip having a power supply circuit including a resonant circuit having a predetermined resonant frequency; and

a radiation plate arranged to externally radiate a transmission signal supplied from the power supply circuit and to supply a reception signal externally transmitted to the power supply circuit;

wherein

the radiation plate is connected to the power supply circuit via an electric field or the radiation plate is coupled to the power supply circuit via a magnetic field; and

the radiation plate is a two-surface-open radiation plate including at least one radiation portion arranged to externally exchange a transmission-reception signal and a power supply portion arranged to exchange a transmission-reception signal with the power supply circuit.

2. The wireless IC device according to claim 1, wherein the power supply portion is arranged such that at least a portion thereof is positioned in a projection plane of the power supply circuit and an area of the power supply portion is less than an area of the projection plane of the power supply circuit.

3. The wireless IC device according to claim 2, wherein a longitudinal length of the power supply portion extends across the projection plane of the power supply circuit.

4. The wireless IC device according to claim 2, wherein the at least one radiation portion includes a plurality of radiation portions that are provided at opposed sides of the power supply portion.

5. The wireless IC device according to claim 2, wherein the at least one radiation portion is provided at only one end of the power supply portion.

6. The wireless IC device according to claim 1, wherein a plurality of power supply circuits are provided on the wireless IC chip and the power supply portion is arranged so as to be positioned between projection planes of the plurality of power supply circuits.

7. The wireless IC device according to claim 6, wherein the power supply portion is arranged such that a longitudinal length thereof extends across the projection planes of the plurality of power supply circuits.

8. The wireless IC device according to claim 1, wherein the radiation plate is arranged substantially in an x-y plane.

9. The wireless IC device according to claim 8, wherein the radiation plate includes radiation portions extending substantially in an x-axis direction and a y-axis direction.

10. The wireless IC device according to claim 1, wherein the radiation plate includes radiation portions extending substantially in an x-axis direction, a y-axis direction, and a z-axis direction in an x-y-z plane.

11. The wireless IC device according to claim 1, wherein an area of a projection plane of the power supply portion is substantially equal to or greater than an area of a projection plane of the power supply circuit.

12. The wireless IC device according to claim 1, wherein the radiation portion extends in a direction substantially perpendicular to a plane on which the power supply circuit is arranged.

13. The wireless IC device according to claim 1, wherein the power supply portion and the power supply circuit are covered with a magnetic body.

14. The wireless IC device according to claim 1, wherein an electrical length of the radiation plate is substantially an integral multiple of a half wavelength of the transmission-reception signal.

15. The wireless IC device according to claim 1, wherein the radiation plate is made of a flexible metal film.

16. The wireless IC device according to claim 15, wherein the metal film is supported by a flexible film.

17. The wireless IC device according to claim 1, wherein the power supply circuit includes a coiled electrode pattern.

18. The wireless IC device according to claim 17, wherein the power supply portion is a coiled electrode pattern having substantially the same shape as that of the power supply circuit.