TUNABLE WIRELESS POWER DEVICE

• US 20110291490A1
• Filed: 02/18/2011
• Published: 12/01/2011
• Est. Priority Date: 05/28/2010
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Kasturi, Sreenivas, Shi, Guining
• Granted Patent: US 9,240,633 B2
• Time in Patent Office: Days
• US Class Current: 307/104
• CPC Class Codes: H01Q 1/22 by structural association with other equipment or articles
• CPC Class Codes: H01Q 1/52 Means for reducing coupling between antennas; Means for reducing coupling between an antenna and another structure absorbing means H01Q17/00
• 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: H02J 50/005 Mechanical details of housing or structure aiming to accommodate the power transfer means, e.g. mechanical integration of coils, antennas or transducers into emitting or receiving devices
• CPC Class Codes: H02J 50/12 of the resonant type
• CPC Class Codes: H02J 50/20 using microwaves or radio frequency waves
• CPC Class Codes: H02J 50/70 involving the reduction of electric, magnetic or electromagnetic leakage fields
• CPC Class Codes: H04B 5/26 using coils
• CPC Class Codes: H04B 5/79 for data transfer in combination with power transfer

Abstract

Exemplary embodiments are directed to wireless power devices. A device may include a transmit antenna and a metallic structure spaced from and configured for detuning the transmit antenna. The device may further include a circuit for tuning the transmit antenna.

Claims

1. A device, comprising:

a transmit antenna;

a metallic structure spaced from and configured for detuning the transmit antenna; and

a circuit for tuning the transmit antenna.

2. The device of claim 1, the metallic structure configured to induce eddy currents to detune the transmit antenna.

3. The device of claim 1, the metallic structure comprising a metal sheet.

4. The device of claim 1, the metallic material and the transmit antenna being separated by a distance in the range of substantially 20 to 33 millimeters.

5. The device of claim 1, further comprising a magnetic material positioned between the transmit antenna and the metallic structure.

6. The device of claim 5, the magnetic material comprising a ferromagnetic structure.

7. The device of claim 1, the circuit comprising a matching circuit for tuning the transmit antenna in the presence of the metallic structure.

8. The device of claim 1, further comprising a separator positioned between the metallic structure and an external surface of the device.

9. The device of claim 1, the separator having a height of substantially 1 millimeter.

10. The device of claim 1, the transmit antenna, the metallic structure, and the circuit integrated within a wireless power transmitter.

11. The device of claim 1, the metallic structure having one of a rectangular shape, a square shape, and a circular shape.

12. A method, comprising:

inducing a magnetic field from a metallic structure within a wireless power device, an area of the metallic structure substantially equal to or greater than an area of a transmit antenna of the wireless power device; and

tuning the transmit antenna in the presence of the magnetic field.

13. The method of claim 12, the inducing comprising inducing eddy currents in the metallic structure while tuning the transmit antenna.

14. The method of claim 12, the tuning comprising tuning the transmit antenna in the presence of the metallic structure separated from the transmit antenna a distance in the range of substantially 20 to 33 millimeters.

15. The method of claim 12, the tuning comprising tuning the transmit antenna with a matching circuit.

16. The method of claim 12, the inducing a magnetic field from a metallic structure comprising inducing the magnetic field from a metallic sheet.

17. The method of claim 12, the tuning comprising tuning the transmit antenna in the presence of a magnetic material proximate the metallic structure.

18. The method of claim 17, the tuning the transmit antenna in the presence of a magnetic material comprising tuning the transmit antenna in the presence of a ferromagnetic structure.

19. The method of claim 12, further comprising wirelessly transmitting power at a transfer efficiency of substantially 68% while the wireless power device is positioned proximate an external metallic structure.

20. The method of claim 12, the tuning comprising tuning the transmit antenna in the presence of the metallic structure spaced from a surface of the wireless power device.

21. The method of claim 12, the tuning comprising tuning the transmit antenna in the presence of the metallic structure having one of a rectangular shape, a square shape, and a circular shape.

22. A device, comprising:

means for inducing a magnetic field from a metallic structure within a wireless power device, an area of the metallic structure substantially equal to or greater than an area of a transmit antenna of the wireless power device; and

means for tuning the transmit antenna in the presence of the magnetic field.

23. The device of claim 22, the means for inducing comprising means for inducing eddy currents in the metallic structure.

24. The device of claim 22, the means for tuning comprising means for tuning the transmit antenna in the presence of a magnetic material proximate the metallic structure.

25. The device of claim 22, the means for tuning comprising means for tuning the transmit antenna in the presence of the metallic structure separated from the transmit antenna a distance in the range of substantially 20 to 33 millimeters.