Bidirectional wireless power transmission

• US 8,947,041 B2
• Filed: 09/01/2009
• Issued: 02/03/2015
• Est. Priority Date: 09/02/2008
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Cook, Nigel P, Sieber, Lukas, Widmer, Hanspeter
• Primary Examiner(s): Dunn, Drew A
• Assistant Examiner(s): Chung, Steve T
• Application Number:
  US12/552,110
• Publication Number:
  US 20100148723A1
• Time in Patent Office: 1,981 Days
• Field of Search: 320/107, 320/108, 307/104, 336/DIG.2, 363/21.06, 363/21.14
• US Class Current: 320/108
• CPC Class Codes: G06K 19/0701 at least one of the integrated circuit chips comprising an arrangement for power management
• CPC Class Codes: G06K 19/0702 the arrangement including a battery
• CPC Class Codes: G06K 19/0715 the arrangement including means to regulate power transfer to the integrated circuit
• CPC Class Codes: G06K 19/0723 the record carrier comprising an arrangement for non-contact communication, e.g. wireless communication circuits on transponder cards, non-contact smart cards or RFIDs
• 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 7/0008 General problems related to the reading of electronic memory record carriers, independent of its reading method, e.g. power transfer
• CPC Class Codes: G06K 7/10207 parameter settings related to power consumption of the interrogator
• CPC Class Codes: H02J 50/10 using inductive coupling
• CPC Class Codes: H02J 50/12 of the resonant type

Abstract

Exemplary embodiments are directed to wireless power transfer. A wireless power transceiver and device comprise an antenna including a parallel resonator configured to resonate in response to a substantially unmodulated carrier frequency. The wireless power transceiver further comprises a bidirectional power conversion circuit coupled to the parallel resonator. The bidirectional power conversion circuit is reconfigurable to rectify an induced current received at the antenna into DC power and to induce resonance at the antenna in response to DC power.

Claims

1. A wireless power transceiver, comprising:

an antenna configured to generate a current signal in response to a received signal having an unmodulated frequency; and

a power conversion circuit coupled to the antenna, the power conversion circuit comprising a synchronous rectifier configured to rectify the current signal received at the antenna into a direct current (DC), the synchronous rectifier comprising a switch configured to be driven in response to the current signal and a voltage measured at the switch, the power conversion circuit further configured to generate output current into the antenna from a power source.

2. The transceiver of claim 1, wherein the synchronous rectifier includes at least two opposingly activated switches including shunt diodes thereacross to rectify received wireless power prior to activation of the switches.

3. The transceiver of claim 1, wherein the power conversion circuit includes switching capacitance merged into a capacitance in the antenna, and wherein the antenna comprises a resonator.

4. The transceiver of claim 3, wherein a resonant frequency of the resonator is determined based at least in part on the switching capacitance.

5. The transceiver of claim 1, wherein the power conversion circuit is configured to operate as a power source to the antenna and as a power sink from the antenna.

6. The transceiver of claim 1, wherein the power conversion circuit is a bidirectional power conversion circuit.

7. The transceiver of claim 1, wherein the power conversion circuit comprises a control circuit configured to control whether the power conversion circuit rectifies the current signal or generates the output current into the antenna.

8. The transceiver of claim 7, wherein the control circuit is configured to generate a switch waveform that controls the operation of the synchronous rectifier.

9. The transceiver of claim 8, wherein the switch waveform is configured to control an amount of the output current generated into the antenna.

10. The transceiver of claim 7, wherein the switch comprises at least two switches driven by the control circuit, wherein the at least two switches are configured to control whether the synchronous rectifier rectifies the current signal or generates the output current into the antenna, and wherein the control circuit is configured to drive each switch based on a voltage and a current sensed on each respective switch.

11. The transceiver of claim 10, wherein the antenna is tuned by the control circuit to eliminate a phase shift between a tank voltage of the antenna and a current waveform of the at least two switches when in a transmit mode.

12. The transceiver of claim 10, wherein the antenna is tuned to a frequency other than a resonant frequency when in a receive mode.

13. The transceiver of claim 10, wherein the control circuit is configured to generate switch waveforms to drive the at least two switches.

14. The transceiver of claim 13, wherein the control circuit is configured to continuously adjust the switch waveform such that a frequency and a phase of the current signal are synchronized with a frequency and a phase of the switch waveforms when in a receive mode.

15. The transceiver of claim 10, wherein the at least two switches comprise a pair of matched Field Effect Transistors (FETs).

16. The transceiver of claim 10, wherein the at least two switches are configured to enable the power conversion circuit to rectify received high frequency power to provide power to the control circuit when power in the power source is depleted.

17. A device, comprising:

a battery configured to store and donate power; and

a wireless power transceiver coupled to the battery and configured to store power in the battery, the wireless power transceiver further configured to transmit power received from the battery through a power conversion circuit wirelessly using an antenna, the power wirelessly received and communicated through the power conversion circuit, the power conversion circuit comprising a synchronous rectifier that includes a switch configured to be driven in response to the power wirelessly received and a voltage measured at the switch.

18. The device of claim 17, wherein the switch comprises switching capacitance associated therewith, the synchronous rectifier configured with the switching capacitance merged with capacitance associated with an antenna, the antenna configured to generate a current signal in response to a received signal having an unmodulated frequency.

19. The device of claim 18, wherein a resonant frequency of the antenna is determined based at least in part on the switching capacitance.

20. The device of claim 17, wherein the synchronous rectifier includes two opposingly activated switches including shunt diodes thereacross to rectify received wireless power prior to activation of the switches.

21. The device of claim 17, further comprising host device electronics configured to restrict donating excessive power from the battery.

22. The device of claim 17, wherein the power conversion circuit is a bidirectional power conversion circuit.

23. The device of claim 17, wherein the power conversion circuit comprises a control circuit configured to control whether the wireless power transceiver stores power wirelessly received in the battery or transmits power received from the battery.

24. The device of claim 23, wherein the control circuit is configured to generate a switch waveform that controls the operation of the synchronous rectifier.

25. The device of claim 24, wherein the switch waveform is configured to control an amount of the power received from the battery.

26. The device of claim 23, wherein the switch comprises at least two switches driven by the control circuit, wherein the at least two switches are configured to control whether the synchronous rectifier stores power wirelessly received in the battery or transmits power received from the battery, and wherein the control circuit is configured to drive each switch based on a voltage and a current sensed on each respective switch.

27. The device of claim 26, wherein the control circuit is configured to tune the antenna to eliminate a phase shift between a tank voltage of the antenna and a current waveform of the at least two switches when the wireless power transceiver transmits power received from the battery.

28. The device of claim 26, wherein the antenna is tuned to a frequency other than a resonant frequency when power is stored in the battery.

29. The device of claim 26, wherein the control circuit is configured to generate switch waveforms to drive the at least two switches.

30. The device of claim 26, wherein the at least two switches comprise a pair of matched Field Effect Transistors (FETs).

31. The device of claim 26, wherein the at least two switches are configured to enable the power conversion circuit to rectify received high frequency power to provide power to the control circuit when power in the battery is depleted.

32. A method for transceiving wireless power, comprising:

receiving a current signal generated by an antenna, the current signal generated in response to a received signal having an unmodulated frequency, and rectifying, by a power conversion circuit comprising a synchronous rectifier that includes a switch configured to be driven in response to the current signal and a voltage measured at the switch, the current signal into DC when the power conversion circuit is configured in a receive mode; and

generating, by the power conversion circuit, an output current received from a power source, the output current passing into the antenna when the power conversion circuit is configured in a transmit mode.

33. The method of claim 32, wherein the rectifying comprises actively converting the current signal into the DC.

34. The method of claim 32, wherein the rectifying the current signal and the generating the output current are synchronously timed based upon generated waveforms.

35. The method of claim 32, wherein generating the output current further includes determining a resonant frequency based in part on switching capacitance in the power conversion circuit.

36. The method of claim 32, further comprising restricting donation of excessive power from a battery when stored DC power is limited.

37. The method of claim 32, wherein rectifying the current signal further comprises rectifying, by a bidirectional power conversion circuit, the current signal.

38. The method of claim 32, further comprising controlling whether the power conversion circuit is configured in the receive mode or the transmit mode.

39. The method of claim 38, further comprising generating a switch waveform that controls the operation of the power conversion circuit.

40. The method of claim 38, wherein controlling whether the power conversion circuit is configured in the receive mode or the transmit mode comprises:

controlling, by at least two switches of the synchronous rectifier, whether the synchronous rectifier is configured in the receive mode or the transmit mode; and

driving each switch based on a voltage and a current sensed on each respective switch.

41. The method of claim 40, further comprising tuning the antenna to eliminate a phase shift between a tank voltage of the antenna and a current waveform of the at least two switches when in the transmit mode.

42. The method of claim 40, further comprising tuning the antenna to a frequency other than a resonant frequency of the antenna when in the receive mode.

43. The method of claim 40, further comprising generating switch waveforms to drive the at least two switches.

44. The method of claim 43, further comprising continuously adjusting the switch waveforms such that a frequency and a phase of the current signal are synchronized with a frequency and a phase of the switch waveforms when in the receive mode.

45. The method of claim 40, wherein the at least two switches comprise a pair of matched Field Effect Transistors (FETs).

46. The method of claim 40, further comprising enabling the power conversion circuit to rectify received high frequency power to provide power to a control circuit when power in the power source is depleted.

47. A wireless power transceiver, comprising:

means for receiving a current signal generated by an antenna, the current signal generated in response to a received signal having an unmodulated frequency when a power conversion circuit is configured in a receive mode;

means for synchronously rectifying the current signal into a direct current (DC) that provides DC power for storage in a battery when the power conversion circuit is configured in the receive mode, the means for synchronously rectifying comprising a means for switching driven in response to the current signal and a voltage measured at the means for switching; and

means for generating output current from a power source, the output current passing into the antenna when the power conversion circuit is configured in a transmit mode.

48. The wireless power transceiver of claim 47, wherein the means for synchronously rectifying comprises means for actively converting the current signal into the DC.

49. The wireless power transceiver of claim 47, wherein the means for synchronously rectifying the current signal and the means for generating the output current are synchronously timed based upon generated waveforms.

50. The wireless power transceiver of claim 47, wherein the means for generating the output current further comprises means for determining a resonant frequency based in part on switching capacitance in the power conversion circuit.

51. The wireless power transceiver of claim 47, wherein the means for synchronously rectifying the current signal further comprises means for rectifying the current signal when a bidirectional power conversion circuit is configured in the receive mode.

52. The wireless power transceiver of claim 47, further comprising means for controlling whether the power conversion circuit is configured in the receive mode or the transmit mode.

53. The wireless power transceiver of claim 52, further comprising means for generating a switch waveform that controls the operation of the power conversion circuit.

54. The wireless power transceiver of claim 52, wherein means for controlling whether the power conversion circuit is configured in the receive mode or the transmit mode comprises at least two switches of the means for synchronously rectifying, wherein the at least two switches are driven based on a voltage and a current sensed on each respective switch.

55. The wireless power transceiver of claim 54, further comprising means for tuning the antenna to eliminate a phase shift between a tank voltage of the antenna and a current waveform of the at least two switches when in the transmit mode.

56. The wireless power transceiver of claim 54, further comprising means for tuning the antenna to a frequency other than a resonant frequency when in the receive mode.

57. The wireless power transceiver of claim 54, further comprising means for generating switch waveforms to drive the at least two switches.

58. The wireless power transceiver of claim 54, further comprising means for continuously adjusting the switch waveforms such that a frequency and a phase of the current signal are synchronized with a frequency and a phase of the switch waveforms when in the receive mode.

59. The wireless power transceiver of claim 54, wherein the at least two switches comprise a pair of matched Field Effect Transistors (FETs).

60. The wireless power transceiver of claim 54, further comprising means for enabling the power conversion circuit to rectify received high frequency power to provide power to a control circuit when power in the power source is depleted.