WIRELESS IC DEVICE

• US 20090146821A1
• Filed: 02/23/2009
• Published: 06/11/2009
• Est. Priority Date: 07/09/2007
• Status: Active Grant

• Current Assignee: Murata Manufacturing Co Limited
• Original Assignee: Murata Manufacturing Co Limited
• Inventors: KATO, Noboru, IKEMOTO, Nobuo
• Granted Patent: US 8,193,939 B2
• Time in Patent Office: Days
• US Class Current: 340/572.700
• CPC Class Codes: G06K 19/041 Constructional details G06K19/06 takes precedence
• CPC Class Codes: G06K 19/07745 Mounting details of integrated circuit chips
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/0002 Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00
• 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

Abstract

A wireless-IC-device main component is disposed on a surface opposite to a surface for receiving signals from a reader/writer. The wireless-IC-device main component includes an insulating substrate, which is provided with a loop electrode and an electromagnetically coupled module coupled to the loop electrode. A signal from the reader/writer causes an eddy current to flow across a conductor principal plane of a metal article. The eddy current causes a magnetic field to be generated in a direction perpendicular or substantially perpendicular to the conductor principal plane of the metal article. Then, the loop electrode is coupled to the magnetic field. Thus, the wireless-IC-device main component functions as an RFID tag even for signals from the principal plane opposite to the wireless-IC-device main component. Thus, it is possible to reduce the cost of manufacturing a metal article, and to provide a wireless IC device using the metal article as a radiator.

Claims

1. A wireless IC device comprising:

a high-frequency device defined by an electromagnetically coupled module or a wireless IC chip, the electromagnetically coupled module including the wireless IC chip and a feed circuit board coupled to an external circuit and electrically connected to or electromagnetically coupled to the wireless IC chip;

a radiation electrode defining a radiator; and

a loop electrode coupled to the high-frequency device and the radiation electrode, and including a loop plane perpendicular or inclined relative to a plane of the radiation electrode.

2. The wireless IC device according to claim 1, wherein the loop electrode is electromagnetically coupled to the radiation electrode with an insulating layer interposed therebetween.

3. The wireless IC device according to claim 1, wherein the loop electrode is directly electrically connected to the radiation electrode, and a portion of the radiation electrode functions as a portion of the loop electrode.

4. The wireless IC device according to claim 1, further comprising a matching circuit arranged between a mounting area of the high-frequency device and the loop electrode, the matching circuit being arranged to directly electrically connect the high-frequency device to the loop electrode.

5. The wireless IC device according to claim 1, further comprising at least one of a resonant circuit or a matching circuit in the feed circuit board.

6. The wireless IC device according to claim 5, wherein a resonance frequency of the resonant circuit is substantially equal to a frequency of a signal transmitted and received by the radiation electrode.

7. The wireless IC device according to claim 1, wherein the at least one of the high-frequency device or the loop electrode is covered with plastic.

8. The wireless IC device according to claim 1, wherein the high-frequency device and the loop electrode are made of molded plastic disposed on the radiation electrode.

9. The wireless IC device according to claim 1, wherein the radiation electrode is a cylindrical or substantially cylindrical metal article having a conductive layer.

10. The wireless IC device according to claim 1, wherein the radiation electrode is an electrode pattern provided on a circuit board inside electronic equipment.

11. The wireless IC device according to claim 1, wherein the radiation electrode is a metal plate provided in a component inside electronic equipment.

12. The wireless IC device according to claim 1, wherein the loop electrode is disposed on a surface opposite to an electromagnetic wave transmission/reception surface outside the radiation electrode.

13. The wireless IC device according to claim 12, wherein the loop electrode is covered with the radiation electrode or a conductive surface including the radiation electrode.