SYSTEMS AND METHODS FOR SENSING REVERSE LINK SIGNALING

• US 20130221911A1
• Filed: 09/21/2012
• Published: 08/29/2013
• Est. Priority Date: 02/28/2012
• Status: Abandoned Application

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Low, Zhen Ning, Wheatley, Charles E.
• Application Number:
  US13/624,295
• Publication Number:
  US 20130221911A1
• Time in Patent Office: Days
• US Class Current: 320/108
• CPC Class Codes: H01F 38/14 Inductive couplings for wireless supply or distribution of electric power using inductive coupling H02J50/10
• CPC Class Codes: H02J 50/12 of the resonant type
• CPC Class Codes: H02J 50/60 responsive to the presence of foreign objects, e.g. detection of living beings
• CPC Class Codes: H04B 5/26 using coils
• CPC Class Codes: H04B 5/72 for local intradevice communication
• CPC Class Codes: H04B 5/79 for data transfer in combination with power transfer

Abstract

Systems and methods for sensing reverse link signaling are described herein. In one aspect, an apparatus for wireless transmission includes a push-pull driver circuit, coil, and sensor. The push-pull driver circuit is configured to generate a signal. The coil is electrically coupled to the push-pull driver circuit, and the coil is configured to receive the signal from the push-pull driver circuit and wirelessly transmit the signal to a receiver. The sensor is electrically coupled to a virtual alternating current (AC) ground of the push-pull driver circuit or the coil. The sensor is configured to sense a shift in voltage at the virtual AC ground where the shift in voltage is representative of a change of an input impedance of the receiver.

Claims

1. An apparatus for wireless power transmission, comprising:

a push-pull driver circuit configured to generate a signal;

a coil electrically coupled to the push-pull driver circuit, the coil configured to receive the signal from the push-pull driver circuit and wirelessly transmit the signal to a receiver; and

a sensor electrically coupled to a virtual alternating current (AC) ground of the push-pull driver circuit or the coil, the sensor configured to sense a shift in voltage at the virtual AC ground, the shift in voltage representative of a change of an input impedance of the receiver.

2. The apparatus of claim 1, wherein the push-pull driver circuit comprises a switch-mode driver.

3. The apparatus of claim 2, wherein the push-pull driver circuit comprises a Class E switch-mode driver.

4. The apparatus of claim 1, wherein the sensor is configured to sense the shift in voltage by measuring a change in average voltage at the virtual AC ground.

5. The apparatus of claim 1, wherein the coil is configured to wirelessly transmit energy at a level sufficient to power or charge the receiver or a load coupled to the receiver.

6. The apparatus of claim 1, wherein the apparatus is configured to receive wireless communications from the receiver via an interaction by the receiver with a wireless power transfer field generated by the coil.

7. The apparatus of claim 1, further comprising a controller electrically coupled the sensor, the controller configured to:

receive a sensor signal from the sensor indicative of the sensed shift in voltage at the virtual AC ground, and

process the sensor signal.

8. The apparatus of claim 7, wherein the controller is further configured to cause the push-pull driver circuit to stop generating or transmitting the signal based on the sensor signal.

9. The apparatus of claim 7, wherein the controller is configured to cause the coil to stop receiving or wirelessly transmitting the signal based on the sensor signal.

10. The apparatus of claim 1, wherein the virtual AC ground is not connected to a direct current (DC) ground.

11. A method of wireless power transmission, comprising:

generating a signal with a push-pull driver circuit;

transmitting wirelessly with a coil the signal to a receiver; and

sensing with a sensor a shift in voltage at a virtual AC ground of the push-pull driver circuit or the coil, the shift in voltage representative of a change of an input impedance of the receiver.

12. The method of claim 11, wherein the push-pull driver circuit comprises a switch-mode driver.

13. The method of claim 12, wherein the push-pull driver circuit comprises a Class E switch-mode driver.

14. The method of claim 11, wherein sensing the shift in voltage at the virtual AC ground comprises measuring a change in average voltage at the virtual AC ground.

15. The method of claim 11, wherein the coil is configured to wirelessly transmit energy at a level sufficient to power or charge the receiver or a load coupled to the receiver.

16. The method of claim 11, further comprising receiving wireless communications from the receiver via an interaction by the receiver with a wireless power transfer field generated by the coil.

17. The method of claim 11, further comprising:

receiving a sensor signal indicative of the sensed shift in voltage at the virtual AC ground; and

processing the sensor signal.

18. The method of claim 17, further comprising causing the push-pull driver circuit to stop generating the signal based on the sensor signal.

19. The method of claim 17, further comprising causing the coil to stop wirelessly transmitting the signal based on the sensor signal.

20. The method of claim 11, wherein the virtual AC ground is not connected to a direct current (DC) ground.

21. An apparatus for wireless power transmission, comprising:

means for generating a signal;

means for transmitting wirelessly the signal to a receiver; and

means for sensing a shift in voltage at a virtual AC ground of the means for generating or the means for transmitting, the shift in voltage representative of a change of an input impedance of the receiver.

22. A non-transitory computer storage that stores executable program instructions that direct a wireless power transmitter to perform a process that comprises:

generating a signal with a push-pull driver circuit to cause a coil to wirelessly transmit the signal to a receiver; and

sensing with a sensor a shift in voltage at a virtual AC ground of the push-pull driver circuit or the coil, the shift in voltage representative of a change of an input impedance of the receiver.