Systems and methods for detecting and identifying a wireless power device

• US 9,608,480 B2
• Filed: 01/28/2016
• Issued: 03/28/2017
• Est. Priority Date: 09/09/2011
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Lee, Kevin Douglas, Low, Zhen Ning
• Primary Examiner(s): Tran, Thienvu
• Assistant Examiner(s): Stables, David M
• Application Number:
  US15/009,677
• Publication Number:
  US 20160226314A1
• Time in Patent Office: 425 Days
• Field of Search: None
• US Class Current: 1/1
• CPC Class Codes: H02J 50/12 of the resonant type
• CPC Class Codes: H02J 50/90 involving detection or optimisation of position, e.g. alignment
• CPC Class Codes: H04B 5/24 Inductive coupling
• CPC Class Codes: H04B 5/48 Transceivers
• CPC Class Codes: H04B 5/72 for local intradevice communication
• CPC Class Codes: H04B 5/73 for taking measurements, e.g. using sensing coils
• CPC Class Codes: H04B 5/77 for interrogation
• CPC Class Codes: H04B 5/79 for data transfer in combination with power transfer

Abstract

Embodiments are directed to detecting and identifying a type of a wireless power device in a wireless power transfer field. According to one aspect, a method for identifying a type of an object within a power transfer region of a wireless power transmitter configured to transfer power to a device including a wireless power receiver is provided. The method includes monitoring a change in a power drawn by the wireless power transmitter. The method further includes receiving, from the wireless power receiver, a signal indicative of a change in power received by the wireless power receiver. The method further includes identifying the type of the object based on the monitored change in the power drawn and the received signal.

Claims

1. An apparatus for detecting a non-compliant device within a power delivery region of a wireless power transmitter configured to transfer power to one or more wireless power receivers, the apparatus comprising:

a transmit circuit configured to generate a wireless field within the power delivery region that provides the power to the one or more wireless power receivers; and

a controller configured to;

determine an expected impedance response of the transmit circuit based on an electrical characteristic of the one or more wireless power receivers,

monitor an impedance response of the transmit circuit that is indicative of a resistive impedance shift observed by the transmit circuit, and

identify a presence of the non-compliant device based on determining a difference between the expected impedance response and the monitored impedance response.

2. The apparatus of claim 1, wherein the controller is further configured to identify the presence of the non-compliant device based on determining that the difference between the expected impedance response and the monitored impedance response exceeds a threshold.

3. The apparatus of claim 1, wherein the expected impedance response is based on a first change in current expected to be drawn by the transmit circuit, and wherein the monitored impedance response is based on a second change in current actually drawn by the transmit circuit.

4. The apparatus of claim 1, wherein the expected impedance response is based on a look-up table accessible by the controller.

5. The apparatus of claim 1, wherein the electrical characteristic of the one or more wireless power receivers comprises a voltage level generated by the one or more wireless power receivers.

6. The apparatus of claim 1, further comprising a receiver circuit configured to receive a measurement of the electrical characteristic from the one or more wireless power receivers.

7. The apparatus of claim 1, wherein the non-compliant object is one of a near-field communication (NFC) device, a radio frequency identification (RFID) device, and an unauthorized wireless power receiver.

8. The apparatus of claim 1, wherein the controller is further configured to transition the transmit circuit from providing the power at a first power level to a second power level upon identifying the presence of the non-compliant device, the first power level higher than the second power level.

9. The apparatus of claim 1, wherein the difference between the expected impedance response and the monitored impedance response is a resistive impedance shift with no additional resistive impedance shift.

10. The apparatus of claim 8, wherein the controller circuit is further configured to identify a type of the non-compliant object based on an amount of the resistive or reactive impedance change in the difference between the expected impedance response and the monitored impedance response.

12. The method of claim 9, wherein identifying the presence of the non-compliant device is based on determining that the difference between the expected impedance response and the monitored impedance response exceeds a threshold.

13. The method of claim 9, wherein the expected impedance response is based on a first change in current expected to be drawn by the wireless power transmitter, and wherein the monitored impedance response is based on a second change in current actually drawn by the wireless power transmitter.

14. The method of claim 9, wherein the electrical characteristic of the one or more wireless power receivers comprises a voltage level generated by the one or more wireless power receivers.

15. The method of claim 9, further comprising receiving a measurement of the electrical characteristic from the one or more wireless power receivers.

16. The method of claim 9, further comprising transitioning the wireless power transmitter from providing the power at a first power level to a second power level upon identifying the presence of the non-compliant device, the first power level higher than the second power level.

18. The apparatus of claim 15, further comprising means for identifying the presence of the non-compliant device based on determining that the difference between the expected impedance response and the monitored impedance response exceeds a threshold.

19. The apparatus of claim 15, wherein the expected impedance response comprises a first change in current expected to be drawn by the transmit circuit, and wherein the monitored impedance response comprises a second change in current actually drawn by the transmit circuit.

20. The apparatus of claim 15, further comprising means for transitioning the wireless power transmitter from providing the power at a first power level to a second power level upon identifying the presence of the non-compliant device, the first power level higher than the second power level.

11. A method for detecting a non-compliant device within a power delivery region of a wireless power transmitter configured to transfer power to one or more wireless power receivers, comprising:

generating a wireless field within the power delivery region that provides the power to the one or more wireless power receivers; and

determining an expected impedance response of the wireless power transmitter based on an electrical characteristic of the one or more wireless power receivers,

monitoring an impedance response of the wireless power transmitter that is indicative of a resistive impedance shift observed by the wireless power transmitter, and

identifying a presence of the non-compliant device based on determining a difference between the expected impedance response and the monitored impedance response.

17. An apparatus for detecting a non-compliant device within a power delivery region of a wireless power transmitter configured to transfer power to one or more wireless power receivers, the apparatus comprising:

means for generating a wireless field within the power delivery region that provides the power to the one or more wireless power receivers;

means for determining an expected impedance response of the generating means based on an electrical characteristic of the one or more wireless power receivers,

means for monitoring an impedance response of the generating means that is indicative of a resistive impedance shift observed by the transmit circuit, and

means for identifying a presence of the non-compliant device based on determining a difference between the expected impedance response and the monitored impedance response.