Wireless IC device, electronic apparatus, and method for adjusting resonant frequency of wireless IC device

• US 8,360,325 B2
• Filed: 08/24/2010
• Issued: 01/29/2013
• Est. Priority Date: 04/14/2008
• Status: Active Grant

• Current Assignee: Murata Manufacturing Co Limited
• Original Assignee: Murata Manufacturing Co Limited
• Inventors: Kataya, Takeshi, Kato, Noboru, Ishino, Satoshi, Ikemoto, Nobuo, Kimura, Ikuhei, Dokai, Yuya, Shiroki, Koji
• Primary Examiner(s): Lee, Michael G
• Assistant Examiner(s): GUDORF, LAURA A
• Application Number:
  US12/861,945
• Publication Number:
  US 20100308118A1
• Time in Patent Office: 889 Days
• Field of Search: 235/375, 235/492, 235/487, 235/924, 343/700.MS, 343/795, 343/873, 257/532, 257/735
• US Class Current: 235/492
• CPC Class Codes: H01L 2224/16225 the item being non-metallic, e.g. insulating substrate with or without metallisation
• CPC Class Codes: H01L 2224/73204 the bump connector being embedded into the layer connector
• 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 1/38 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 1/48 Earthing means; Earth screens; Counterpoises
• 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 9/285 Planar dipole H01Q9/065 takes precedence; patch antenna H01Q9/0407
• CPC Class Codes: H01Q 9/40 Element having extended radiating surface
• CPC Class Codes: H05K 1/16 incorporating printed electric components, e.g. printed resistor, capacitor, inductor
• CPC Class Codes: Y10T 29/49016 Antenna or wave energy "plumbing" making

Abstract

A wireless IC device and an electronic apparatus are obtained, which can achieve miniaturization and improve the gain of a radiator plate (electrode) without providing a dedicated antenna. A wireless IC device is provided, in which a loop electrode is provided in a ground electrode provided on a printed wiring circuit board, and in which a wireless IC chip that processes a transmission/reception signal or an electromagnetic coupling module is coupled to the loop electrode. The ground electrode is coupled to the wireless IC chip or the electromagnetic coupling module via the loop electrode, and transmits or receives a high-frequency signal. The ground electrode is formed with a slit for adjusting a resonant frequency thereof.

Claims

1. A wireless IC device comprising:

a wireless IC chip that includes input/output terminal electrodes and processes a transmission/reception signal;

a printed wiring circuit board on which the wireless IC chip is mounted;

a ground electrode provided on the printed wiring circuit board; and

a loop electrode including first and second ends and provided on the printed wiring circuit board so as to be coupled to the wireless IC chip and the ground electrode, wherein

the loop electrode is coupled to the input/output terminal electrodes of the wireless IC chip at the first and second ends and is coupled to the ground electrode; and

the ground electrode includes a slit and/or a cutout arranged to adjust a resonant frequency thereof.

3. The wireless IC device according to claim 1, wherein the loop electrode has an impedance matching function.

4. The wireless IC device according to claim 1, wherein the loop electrode and the ground electrode provided on the printed wiring circuit board are disposed so as to be insulated from each other.

5. The wireless IC device according to claim 1, the loop electrode and the ground electrode provided on the printed wiring circuit board are disposed so as to be electrically conductive to each other.

6. The wireless IC device according to claim 1, wherein the loop electrode is disposed around a cutout provided in the ground electrode.

7. The wireless IC device according to claim 6, further comprising a matching electrode inside the loop electrode.

8. The wireless IC device according to claim 1, wherein the slit and/or the cutout is disposed at a side at which the wireless IC chip is disposed.

9. The wireless IC device according to claim 1, wherein the slit and/or the cutout is disposed at a side opposite to a side at which the wireless IC chip is disposed.

10. The wireless IC device according to claim 1, wherein the slit and/or the cutout is disposed at a side orthogonal to a side at which the wireless IC chip is disposed.

11. The wireless IC device according to claim 1, wherein the slit has an L shape.

12. The wireless IC device according to claim 1, wherein the slit and/or the cutout includes a plurality of slits and/or cutouts arranged such that the ground electrode has a plurality of resonant frequencies.

13. The wireless IC device according to claim 1, wherein the printed wiring circuit board is a multilayer board in which multiple dielectric layers or magnetic layers are laminated.

14. The wireless IC device according to claim 13, wherein the ground electrode is disposed in multiple layers of the printed wiring circuit board.

15. The wireless IC device according to claim 1, wherein a circuit wiring is disposed in the slit and/or the cutout.

16. The wireless IC device according to claim 1, wherein a metal member mounted on the printed wiring circuit board is in a conductive state with the ground electrode.

17. The wireless IC device according to claim 1, wherein the ground electrode includes an inductance component and a capacitance component that are connected in parallel with each other, and another inductance component that is connected in series with the inductance component and the capacitance component.

18. The wireless IC device according to claim 1, further comprising a matching electrode, wherein

the loop electrode and the matching electrode include an inductance component and a capacitance component that are connected in parallel with each other, and another inductance component that is connected in series with the inductance component and the capacitance component.

19. An electronic apparatus comprising the wireless IC device according to claim 1.

2. A wireless IC device comprising:

an electromagnetic coupling module including input/output terminal electrodes, a wireless IC that processes a transmission/reception signal and a power supply circuit board that includes an inductance element coupled to the wireless IC;

a printed wiring circuit board on which the electromagnetic coupling module is mounted;

a ground electrode provided on the printed wiring circuit board; and

a loop electrode including first and second ends and provided on the printed wiring circuit board so as to be coupled to the power supply circuit board and the ground electrode, wherein

the loop electrode is coupled to the input/output terminal electrodes of the electromagnetic coupling module at the first and second ends and is coupled to the ground electrode; and

the ground electrode includes a slit and/or a cutout arranged to adjust a resonant frequency thereof.

20. A method for adjusting a resonant frequency of a wireless IC device that includes:

a wireless IC chip that includes input/output terminal electrodes and processes a transmission/reception signal;

a printed wiring circuit board on which the wireless IC chip is mounted;

a ground electrode provided on the printed wiring circuit board; and

a loop electrode including first and second ends and provided on the printed wiring circuit board so as to be coupled to the wireless IC chip and the ground electrode, wherein the loop electrode is coupled to the input/output terminal electrodes of the wireless IC chip at the first and second ends and is coupled to the ground electrode, the method comprising the step of;

adjusting the resonant frequency by forming a slit and/or a cutout in the ground electrode.

22. The method according to claim 20, wherein by forming a slit and/or a cutout in the ground electrode, an inductance component and a capacitance component that are connected in parallel with each other are formed and another inductance component that is connected in series with the inductance component and the capacitance component is formed to adjust the resonant frequency.

21. A method for adjusting a resonant frequency of a wireless IC device that includes:

an electromagnetic coupling module including input/output terminal electrodes, a wireless IC that processes a transmission/reception signal and a power supply circuit board that includes an inductance element coupled to the wireless IC;

a printed wiring circuit board on which the electromagnetic coupling module is mounted;

a ground electrode provided on the printed wiring circuit board; and

a loop electrode including first and second ends and provided on the printed wiring circuit board so as to be coupled to the power supply circuit board and the ground electrode, wherein the loop electrode is coupled to the input/output terminal electrodes of the electromagnetic coupling module at the first and second ends and is coupled to the ground electrode, the method comprising the step of;

adjusting the resonant frequency by forming a slit and/or a cutout in the ground electrode.