Packaging and details of a wireless power device

• US 8,421,267 B2
• Filed: 03/09/2009
• Issued: 04/16/2013
• Est. Priority Date: 03/10/2008
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Cook, Nigel P., Sieber, Lukas, Widmer, Hanspeter
• Primary Examiner(s): Deberadinis, Robert L.
• Application Number:
  US12/400,703
• Publication Number:
  US 20090224609A1
• Time in Patent Office: 1,499 Days
• Field of Search: 307/20
• US Class Current: 307/20
• 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 50/402 the two or more transmitting or the two or more receiving devices being integrated in the same unit, e.g. power mats with several coils or antennas with several sub-antennas
• CPC Class Codes: H02J 50/60 responsive to the presence of foreign objects, e.g. detection of living beings

Abstract

A wireless power system includes a power source, power receiver, and components thereof. A current sensor senses the amount of current through the antenna. That amount of current is then used to adjust characteristics of the transmitting or receiving.

Claims

1. A wireless power transmitter, comprising:

a magnetically resonant antenna configured to receive a driving signal causing a current to flow through the magnetically resonant antenna;

a transmit circuit configured to generate the driving signal at a frequency that is substantially equal to a resonant frequency of the magnetically resonant antenna; and

a current sensor configured to sense an amount of the current and generate a current sense signal indicative of a degree of coupling or decoupling by the magnetically resonant antenna, the transmit circuit being configured to change the driving signal based on the current sense signal.

2. A transmitter as in claim 1, wherein the antenna is tuned to 13.56 Mhz or 135 KHz.

3. The transmitter as in claim 1, wherein the transmit circuit comprises an inverter configured to generate the driving signal at the frequency.

4. The transmitter as in claim 3, wherein the controller controls operating characteristics of the inverter.

5. The transmitter as in claim 4, wherein the controller controls pulse width and electronic tuning of the inverter.

6. The transmitter as in claim 1, wherein the magnetically resonant antenna comprises at least one component with a specified voltage and/or current rating, and wherein the transmit circuit further comprises an overload protection part, responsive to the amount of current, that prevents voltages and/or currents higher than a predetermined level based on the specified voltage and/or current rating.

7. The wireless power transmitter as in claim 1, wherein the transmit circuit is configured to change the driving signal by at least one of adjusting an amount of power provided by the driving signal or adjusting the frequency of the driving signal.

8. The wireless power transmitter as in claim 1, wherein the transmit circuit comprises at least one of an AC to DC converter, a half bridge inverter, or a tuning circuit, and wherein the transmit circuit is configured to change the driving signal by controlling operating characteristics of at least one of the AC to DC converter, the half bridge, inverter, or the tuning circuit.

9. The wireless power transmitter as in claim 1, wherein the magnetically resonant antenna is configured to wirelessly provide power to a receiver device to power or charge a load based on the driving signal.

10. The wireless power transmitter as in claim 1, wherein the current sensor is configured to sense an amount of the current by sensing a magnitude of the current.

11. A wireless power receiver, comprising:

a magnetically resonant antenna configured to wirelessly receive a signal causing a current to flow through the magnetically resonant antenna;

a receive circuit configured to receive the signal at a frequency that is substantially equal to a resonant frequency of the magnetically resonant antenna, the receive circuit being further configured to generate electrical power from the signal at a level sufficient to power or charge a load; and

a current sensor configured to sense an amount of the current and configured to generate a current sense signal indicative thereof, the receive circuit being configured to change a reception characteristic based on the current sense signal from the current sensor.

12. The receiver as in claim 11, wherein the antenna is tuned to 13.56 MHz or 135 KHz.

13. The receiver as in claim 11, wherein the receive circuit comprises a controller configured to monitor the signal from the current sensor and configured to change the reception characteristic.

14. The receiver as in claim 13, wherein the receive circuit further comprises a rectifier configured to rectify the signal to generate the electrical power, the rectifier being controlled by the controller.

15. The wireless power receiver of claim 13, further comprising a tuning circuit, and wherein the controller is configured to change the reception characteristic by controlling the tuning circuit.

16. The receiver as in claim 14, wherein the rectifier is a synchronous rectifier, and the controller is configured to control a frequency of the synchronous rectifier.

17. The receiver as in claim 14, wherein the rectifier is a synchronous rectifier, and the controller is configured to control characteristics of an adaptive load presented by the rectifier.

18. The receiver as in claim 11, further comprising an overload protection part, responsive to the amount of current, the overload protection part being configured to prevent currents higher than a predetermined level based on ratings of electronic components of the receiver.

19. The receiver as in claim 18, wherein the ratings are ratings of components forming the antenna.

20. The wireless power receiver of claim 11, wherein the reception characteristic comprises at least one of a capacitance or an inductance of the magnetically resonant antenna, an operating characteristic of a rectifier circuit, or an operating characteristic of an adaptive load presented by the rectifier circuit.

21. The wireless power receiver of claim 11, wherein the receive circuit is configured to change a reception characteristic by increasing an amount of power provided by a rectifier circuit in response to the current sense signal indicating that the current is below a threshold.

22. A method for controlling wireless power reception, comprising:

receiving a wireless magnetic signal at an antenna causing a current to flow through the antenna, the antenna being configured to be tuned to a resonant frequency at a first frequency;

converting the wireless magnetic signal to electric power at a level sufficient to power or charge a load using electrical circuitry connected to the antenna;

sensing an amount of the current;

generating a current sense signal indicative thereof; and

changing a characteristic of the electrical circuitry to improve an interface with a source of the wireless magnetic signal based on the current sense signal.

23. The method as in claim 22, wherein the antenna is tuned to 13.56 MHz or 135 KHz.

24. The method as in claim 22, wherein the antenna includes at least one component with a specified voltage and/or current rating and wherein changing a characteristic of the electrical circuitry to prevent currents and/or voltages higher than a predetermined level based on ratings of the at least one component.

25. The method as in claim 22, wherein the source of the wireless magnetic signal comprises a wireless power transmitter.

26. The method as in claim 22, wherein the electrical circuitry comprises a rectifier, and wherein changing the characteristic of the electrical circuitry comprises controlling characteristics of the rectifier.

27. The method as in claim 26, wherein the rectifier is a synchronous rectifier, and wherein controlling characteristics of the rectifier comprises controlling a frequency of the synchronous rectifier.

28. The method as in claim 26, wherein the rectifier is a synchronous rectifier, and wherein controlling characteristics of the rectifier comprises controlling characteristics of an adaptive load presented by the rectifier.

29. The method as in claim 26, wherein controlling characteristics of the rectifier comprises increasing an amount of power provided by the rectifier in response to the current sense signal indicating that the current is below a threshold.

30. The method as in claim 22, wherein the electrical circuitry comprises a DC to DC converter, and wherein changing a characteristic of the electrical circuitry comprises controlling characteristics of the DC to DC converter.

31. A method for controlling wireless power transmission, comprising

converting electrical power to a driving signal at a first frequency using electrical circuitry;

driving an antenna with the driving signal to wirelessly transmit a magnetic signal via an antenna which is tuned to have a resonant frequency at substantially the first frequency;

sensing an amount of current that flows through the antenna;

generating a current sense signal indicative of a degree of coupling or decoupling of the antenna; and

changing a characteristic of the electrical circuitry to adjust a driving signal based on the current sense signal.

32. The method as in claim 31, wherein the antenna is tuned to 13.56 MHz or 135 KHz.

33. The method as in claim 31, wherein changing a characteristic of the electrical circuitry to adjust the driving signal comprises at least one of adjusting an amount of power provided by the driving signal or adjusting the frequency of the driving signal.

34. The method as in claim 31, wherein changing a characteristic of the electrical circuitry to adjust the driving signal comprises controlling operating characteristics of at least one of an AC to DC converter, a half bridge, inverter, or a tuning circuit.

35. The method as in claim 31, wherein wirelessly transmitting the magnetic signal via the antenna comprises wirelessly providing power to a receiver device to power or charge a load.

36. The method as in claim 31, wherein the antenna includes at least one component with a specified voltage and/or current rating, the method further comprising preventing currents and/or voltages higher than a predetermined level based on ratings of the at least one component and based on the current sense signal.

37. A wireless power receiver, comprising

a magnetically resonant antenna;

and

a receive circuit configured to receive a signal at a frequency that is substantially equal to a resonant frequency of the magnetically resonant antenna, the receive circuit being further configured to generate electrical power from the signal at a level sufficient to power or charge a load, the receive circuit including a control unit configured to change a characteristic of electrical power to improve matching with the magnetically resonant antenna, the receive circuit comprising a synchronous rectifier.

38. The receiver as in claim 37, wherein the receive circuit is configured to change a frequency of the synchronous rectifier to improve the matching.

39. The receiver as in claim 37, wherein the receive circuit includes a DC to DC converter.

40. The receiver as in claim 39, wherein the receive circuit is configured to change a characteristic of the DC to DC converter to improve the matching.

41. The receiver as in claim 39, further comprising a current sensor configured to sense an amount of current that flows through the magnetically resonant antenna and being configured to create a signal indicative thereof.

42. The receiver as in claim 37, wherein the antenna is tuned to 13.56 MHz or 135 KHz.

43. A wireless power receiver, comprising:

means for receiving a wireless magnetic signal at an antenna, the antenna having a resonant frequency and being configured to be tunable to the resonant frequency;

means for converting the wireless magnetic signal into electric power, the signal being at a level sufficient to charge or power a load;

means for sensing an amount of current flowing through the means for receiving the wireless magnetic signal;

means for generating a current sense signal indicative of the amount of current flowing; and

means for changing a characteristic of the means for converting the wireless magnetic signal to improve an interface with a source of the wireless magnetic signal based on the current sense signal.

44. The wireless power receiver as in claim 43, wherein the characteristic comprises a capacitance or an inductance of the means for receiving the wireless magnetic signal, an operating characteristic of a rectifier circuit, or an operating characteristic of an adaptive load presented by the rectifier circuit.

45. The wireless power receiver as in claim 43, wherein means for changing the characteristic comprises means for increasing an amount of power provided by a rectifier circuit in response to the current sense signal indicating that the current is below a threshold.

46. A wireless power transmitter, comprising means for wirelessly transmitting power at a level sufficient to charge or power a load of a receiver device, the means for wirelessly transmitting power having a resonant frequency;

means for generating a driving signal at a frequency that is substantially equal to the resonant frequency;

means for sensing an amount of current that flows through the means for wirelessly transmitting power;

means for generating a current sense signal indicative of a degree of coupling or decoupling of the means for wirelessly transmitting power; and

means for changing the driving signal based on the current sense signal.

47. The wireless power transmitter as in claim 46, further comprising means for changing the driving signal based on the current sense signal by adjusting an amount of power provided by the driving signal or adjusting the frequency of the driving signal.

48. A method for receiving wireless power, comprising:

receiving a signal from a magnetically resonant antenna at a receive circuit at a frequency that is substantially equal to a resonant frequency of the magnetically resonant antenna, the receive circuit comprising a synchronous rectifier;

generating electrical power from the signal at a level sufficient to power or charge a load; and

changing a characteristic of electrical power to improve matching with the magnetically resonant antenna.

49. The method as in claim 48, wherein changing the characteristics comprises changing a frequency of the synchronous rectifier to improve the matching.

50. The method as in claim 48, further comprising sensing an amount of current that flows through the magnetically resonant antenna and changing the characteristic based on the amount of current.

51. A wireless power receiver, comprising:

means for receiving a signal at a frequency that is substantially equal to a resonant frequency of a magnetically resonant antenna;

means for generating electrical power from the signal at a level sufficient to power or charge a load; and

means for changing a characteristic of electrical power to improve matching with the receiving means, the means for changing the characteristic comprising means for changing a frequency of a synchronous rectifier.

52. The wireless power receiver as in claim 51, further comprising means for sensing an amount of current that flows through the receiving means and means for changing the characteristic based on the amount of current.

53. A wireless power receiver comprising:

a magnetically resonant antenna;

a receive circuit configured to receive a signal at a frequency that is substantially equal to a resonant frequency of the magnetically resonant antenna, the receive circuit being further configured to generate electrical power from the signal at a level sufficient to power or charge a load;

a power indicator meter; and

a controller configured to change the signal based on an output of the power indicator meter.