Wireless IC device

• US 8,009,101 B2
• Filed: 09/07/2007
• Issued: 08/30/2011
• Est. Priority Date: 04/06/2007
• Status: Expired due to Fees

• Current Assignee: Murata Manufacturing Co Limited
• Original Assignee: Murata Manufacturing Co Limited
• Inventors: Ikemoto, Nobuo, Kato, Noboru
• Primary Examiner(s): Owens; Douglas W
• Assistant Examiner(s): TRAN, CHUC
• Application Number:
  US11/851,651
• Publication Number:
  US 20080246664A1
• Time in Patent Office: 1,453 Days
• Field of Search: 343/700.MS, 343/866, 343/873, 343/895, 343/728, 343/729, 343/737, 343/751, 343/764, 343/853, 235/492
• US Class Current: 343/700.0MS
• 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 19/07767 the first and second communication means being two different antennas types, e.g. dipole and coil type, or two antennas of the same kind but operating at different frequencies
• 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 1/36 Structural form of radiating elements, e.g. cone, spiral, umbrella; Particular materials used therewithH01Q1/08, H01Q1/14 take precedence

Abstract

A wireless IC device includes a spiral line electrode portion and a first capacitance electrode connected to the inner end of the line electrode portion, which are disposed on the top surface of a substrate. A second capacitance electrode opposing the first capacitance electrode and a cross line electrode, which connects the second capacitance electrode and a connecting portion that connects the top and bottom surfaces, are disposed on the bottom surface of the substrate. The connecting portion electrically connects the outer end of the line electrode portion and an end of the cross line electrode. A wireless IC is mounted such that terminal electrodes thereof are connected to the connecting portion and an end of a radiating electrode. A radiating/resonating electrode including the line electrode portion, the capacitance electrodes, and the cross line electrode can act both as a resonant circuit for a resonant tag and as a radiating electrode serving as an RFID tag.

Claims

1. A wireless IC device comprising:

a radiating/resonating electrode disposed on a substrate and defining both as a radiating electrode in a frequency for RFID and as a resonating electrode that resonates at a frequency that is different from the frequency for RFID;

a wireless IC for RFID mounted on the substrate and electrically connected or electromagnetically coupled with the radiating/resonating electrode; and

an additional radiating/resonating electrode disposed on the substrate;

wherein

the wireless IC is electrically connected or coupled with the pair of radiating/resonating electrodes.

2. The wireless IC device according to claim 1, wherein the radiating/resonating electrode includes a line electrode portion and a capacitance electrode portion that forms capacitance between both ends of the line electrode portion.

3. The wireless IC device according to claim 2, wherein the capacitance electrode portion includes two capacitance electrodes opposing each other via a dielectric layer in the thickness direction of the capacitance electrode portion, the line electrode portion has a spiral shape that is coiled around the capacitance electrode portion a plurality of times, the radiating/resonating electrode further includes a cross line electrode that is disposed on the substrate and connects one of the capacitance electrodes with the outer end of the spiral line electrode portion, the other capacitance electrode being connected to the inner end of the spiral line electrode portion, and the wireless IC is mounted in the vicinity of the cross line electrode.

4. The wireless IC device according to claim 2, wherein the capacitance electrode portion includes two capacitance electrodes opposing each other via a dielectric layer in the thickness direction of the capacitance electrode portion, and the wireless IC is mounted in the vicinity of one of the capacitance electrodes.

5. The wireless IC device according to claim 1, wherein the wireless IC is a wireless IC chip that is electrically connected to the radiating/resonating electrode.

6. The wireless IC device according to claim 1, wherein the wireless IC is an electromagnetically coupled module including a feeder circuit board that has a matching circuit including inductors and a wireless IC chip that is disposed on the top surface of the feeder circuit board and is electrically connected to the feeder circuit board.

7. A wireless IC device comprising:

a radiating/resonating electrode disposed on a substrate and defining both as a radiating electrode in a frequency for RFID and as a resonating electrode that resonates at a frequency that is different from the frequency for RFID;

a wireless IC for RFID mounted on the substrate and electrically connected or electromagnetically coupled with the radiating/resonating electrode; and

an additional radiating electrode disposed on the substrate, the additional radiating electrode constituting an equivalent dipole antenna in combination with the radiating/resonating electrode;

wherein

the wireless IC is electrically connected or electromagnetically coupled with the radiating/resonating electrode and the additional radiating electrode;

the radiating/resonating electrode is defined by a first radiating element; and

the additional radiating electrode is defined by a second radiating element that is separate and distinct from the first radiating element.

8. The wireless IC device according to claim 7, wherein a line length of the additional radiating electrode corresponds to approximately a quarter-wavelength of the frequency for RFID, and the resonant frequency of the radiating/resonating electrode is lower than the frequency for RFID.

9. The wireless IC device according to claim 7, wherein the radiating/resonating electrode includes a line electrode portion and a capacitance electrode portion that forms capacitance between both ends of the line electrode portion.

10. The wireless IC device according to claim 9, wherein the capacitance electrode portion includes two capacitance electrodes opposing each other via a dielectric layer in the thickness direction of the capacitance electrode portion, the line electrode portion has a spiral shape that is coiled around the capacitance electrode portion a plurality of times, the radiating/resonating electrode further includes a cross line electrode that is disposed on the substrate and connects one of the capacitance electrodes with the outer end of the spiral line electrode portion, the other capacitance electrode being connected to the inner end of the spiral line electrode portion, and the wireless IC is mounted in the vicinity of the cross line electrode.

11. The wireless IC device according to claim 10, wherein the capacitance electrode portion is disposed inside the spiral line electrode portion, and the additional radiating electrode is disposed outside the spiral line electrode portion.

12. The wireless IC device according to claim 9, wherein the capacitance electrode portion includes two capacitance electrodes opposing each other via a dielectric layer in the thickness direction of the capacitance electrode portion, and the wireless IC is mounted in the vicinity of one of the capacitance electrodes.

13. The wireless IC device according to claim 7, wherein the wireless IC is a wireless IC chip that is electrically connected to the radiating/resonating electrode.

14. The wireless IC device according to claim 7, wherein the wireless IC is an electromagnetically coupled module including a feeder circuit board that has a matching circuit including inductors and a wireless IC chip that is disposed on the top surface of the feeder circuit board and is electrically connected to the feeder circuit board.