WIRELESS POWER PEER TO PEER COMMUNICATION

• US 20120153742A1
• Filed: 10/13/2011
• Published: 06/21/2012
• Est. Priority Date: 12/20/2010
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Lee, Kevin D., Low, Zhen Ning, Irish, Linda S.
• Granted Patent: US 9,899,882 B2
• Time in Patent Office: Days
• US Class Current: 307/104
• CPC Class Codes: G06K 19/0701 at least one of the integrated circuit chips comprising an arrangement for power management
• 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 50/40 using two or more transmitting or receiving devices H02J50/50 takes precedence
• CPC Class Codes: H02J 50/80 involving the exchange of data, concerning supply or distribution of electric power, between transmitting devices and receiving devices

Abstract

Exemplary embodiments are directed to wireless power communication. In one aspect a wireless power receiver configured to receive wireless power from a wireless power transmitter is provided. The wireless power receiver includes a switchable element configured to couple a receive coil to a ground voltage. The wireless power receiver further includes a detector coupled to the receive coil and configured to detect an externally generated pulse.

Claims

1. A wireless power receiver configured to receive wireless power from a wireless power transmitter, the wireless power receiver comprising:

a switchable element configured to couple a receive coil to a ground voltage; and

a detector coupled to the receive coil and configured to detect an externally generated pulse.

2. The wireless power receiver of claim 1, the switchable element comprising a field-effect transistor.

3. The wireless power receiver of claim 1, further comprising a capacitor coupled between the switchable element and the receive coil.

4. The wireless power receiver of claim 1, the switchable element coupled to a node positioned between the receive coil and a rectifier.

5. The wireless power receiver of claim 1, the pulse detector comprising:

an envelope detector;

at least one transistor coupled to the envelope detector and configured to amplify an envelope output from the envelope detector; and

an output coupled to the at least one transistor and configure to generate a logic output.

6. The wireless power receiver of claim 1, the pulse detector further comprising a filter coupled to an output of the envelope detector and the at least one transistor.

7. The wireless power receiver of claim 1, further comprising a pulse stretcher coupled between the receive coil and the detector.

8. The wireless power receiver of claim 1, wherein the detected pulse provides at least a portion of a message indicating an amount of power another receiver has received from the transmitter.

9. The wireless power receiver of claim 1, wherein the detected pulse provides at least a portion of a message indicating a rectifier voltage.

10. The wireless power receiver of claim 1, wherein the detected pulse provides at least a portion of a message indicating an identifier used by another receiver.

11. The wireless power receiver of claim 1, wherein the detected pulse provides at least a portion of a message indicating a negative acknowledgement.

12. The wireless power receiver of claim 1, wherein the switchable element couples the receive coil to a ground to communicate a message to the wireless power transmitter or another receiver.

13. A method of generating a detectable pulse in a wireless power device, comprising varying a duty cycle of a power converter of a wireless power device to generate a detectable pulse for communicating with another wireless power device.

14. A wireless power device, comprising:

a pulse detector coupled to an antenna and configured to detect an externally generated pulse, the pulse detector including;

an envelope detector;

at least one transistor coupled to the envelope detector and configured to amplify an envelope output from the envelope detector; and

an output coupled to the at least one transistor and configure to generate a logic output.

15. The device of claim 14, wherein the envelope detector receives a wireless power signal and outputs the envelope output that is amplified to saturate a transistor when a receiver is not signaling.

16. The device of claim 14, wherein the logic output is used to determine whether a receiver is signaling.

17. A method of communicating a message by a wireless power receiver, comprising:

providing power from the wireless power receiver to a chargeable device; and

shorting a receive coil of the wireless power receiver while charging the device.

18. The method of claim 17, further comprising charging a storage element with energy received at a receive coil.

19. The method of claim 17, wherein the shorting causes an increase in an impedance at an associated transmit coil.

20. The method of claim 17, wherein the shorting causes a decrease in an AC voltage at receive coils of other associated wireless power receivers.

21. A method of identifying a wireless power receiver and communicating a power status of the receiver, comprising:

transmitting a first message type including an identification of a receiver from the receiver to at least one other receiver;

incrementing the identification of the receiver if a message received at the receiver is a second message type; and

transmitting a power message and the identification from the receiver to the at least one other receiver.

22. The method of claim 21, the incrementing comprising incrementing the identification of the receiver if the message received at the receiver is a negative acknowledgment in response to transmitting the first message.

23. The method of claim 21, further comprising transmitting a third message type from the receiver if the message received at the receiver is a fourth message type.

24. The method of claim 23, the transmitting a third message type comprising transmitting a negative acknowledgment if the fourth message type is associated with an identification matching the identification of the receiver.

25. The method of claim 21, further comprising transmitting a fifth message type from the receiver if the message received at the receiver is a sixth message type.

26. The method of claim 25, the transmitting a fifth message type comprising transmitting a negative acknowledgment if the sixth message type is associated with an identification matching the identification of the receiver.

27. A method of adjusting the power of a wireless power transmitter, comprising:

receiving a rectifier voltage signal from one or more receivers within a charging region of the transmitter; and

adjusting a voltage signal within the transmitter if one of the received rectifier voltage signals is either above a first threshold or below a second threshold.

28. The method of claim 27, wherein adjusting a voltage signal comprises decreasing a voltage output from a power amplifier if a received rectifier voltage is greater than the first threshold.

29. The method of claim 27, wherein adjusting the voltage signal comprises increasing a voltage output from a power amplifier if a received rectifier voltage is less than the first threshold.

30. The method of claim 27, further comprising receiving a unique identification for each receiver within the charging region.

31. A wireless power device, comprising:

means for receiving a rectifier voltage signal from each receiver within a charging region of a transmitter; and

means for modifying a voltage signal within the transmitter if the received rectifier voltage is either above a first threshold or below a second, threshold.

32. A wireless power device, comprising:

means for transmitting a first message type including an identification of a receiver from the receiver to at least one other receiver;

means for incrementing the identification of the receiver if a message received at the receiver is a second message type; and

means for transmitting a power message and the identification from the receiver to the at least one other receiver.