Reverse link signaling via receive antenna impedance modulation

Patent metadata

Field	Value
Publication number	US-9954399-B2
Application number	US-201514629314-A
Country	US
Kind code	B2
Filing date	Feb 23, 2015
Priority date	May 13, 2008
Publication date	Apr 24, 2018
Grant date	Apr 24, 2018

Abstract

Exemplary embodiments are directed to wireless power transfer including generating an electromagnetic field at a resonant frequency of a transmit antenna to create a coupling-mode region within a near-field of the transmit antenna. A receive antenna placed within the coupling-mode region resonates at or near the resonant frequency. The receive antenna extracts energy from a coupling between the two antennas. Signaling from the receive antenna to the transmit antenna is performed by generating a first power consumption state for the receive antenna to signal a first receive signal state and generating a second power consumption state for the receive antenna to signal a second receive signal state. Signaling from the transmit antenna to the receive antenna is performed by enabling the resonant frequency on the transmit antenna to signal a first transmit signal state and disabling the resonant frequency on the transmit antenna to signal a second transmit signal state.

First claim

What is claimed is:

1. A wireless power transmitter, comprising:
a transmit antenna configured to generate a magnetic field for coupling charging power in a near-field of the magnetic field to a receive antenna to charge a load of a receiver device electrically coupled to the receive antenna;
an amplifier configured to receive a power signal from a power supply, the amplifier configured to apply a first signal to the transmit antenna; and
a load sensing circuit operably coupled to the amplifier and configured to detect a change in the power signal supplied to the amplifier,
wherein the load sensing circuit is configured to generate a receive signal responsive to the change in the power signal, and
wherein the receive signal is indicative of a data communication from the receiver device communicated via the magnetic field.

2. The wireless power transmitter of claim 1 , wherein the change in the power signal supplied to the amplifier comprises a change in the amount of power drawn by the receive antenna.

3. The wireless power transmitter of claim 1 , wherein the change in the power signal supplied to the amplifier comprises an indication of a change in impedance of the receive antenna, presented to the transmit antenna and caused by an operation of the receiver device.

4. The wireless power transmitter of claim 1 , wherein the data communication comprises a power requirement of the receiver device related to charging the load of the receiver device.

5. The wireless power transmitter of claim 1 , wherein the data communication comprises a request for an adjustment of level of power requirement of the load of the receiver device.

6. The wireless power transmitter of claim 1 , wherein the load sensing circuit comprises:
a sense resistor operably coupled in series between the power supply and the amplifier; and
a differential amplifier comprising:
a first input coupled to the power supply;
a second input coupled to the amplifier; and
an output configured to generate the receive signal.

7. The wireless power transmitter of claim 1 , further comprising: an oscillator operably coupled to the amplifier, wherein the oscillator is configured to generate a transmit modulation signal.

8. The wireless power transmitter of claim 7 , wherein the modulation signal corresponds to a data communication to be communicated to the receiver device via the magnetic field.

9. The wireless power transmitter of claim 7 , wherein:
the amplifier is configured to apply the first signal to the transmit antenna when the transmit modulation signal is in a first state, and
the amplifier is configured to apply a second signal to the transmit antenna when the transmit modulation signal is in a second state.

10. A method of wireless power transmission comprising:
generating, with a transmit antenna in a wireless power transmitter, a magnetic field for coupling charging power in a near-field of the magnetic field to a receive antenna electrically coupled to a receiver device;
supplying a power signal to an amplifier in the wireless power transmitter;
applying a first signal to the transmit antenna via the amplifier;
detecting, in the wireless power transmitter, a change in the power signal supplied to the amplifier;
generating, in the wireless power transmitter, a receive signal responsive to the change in the power signal; and
identifying, from the receive signal and in the wireless power transmitter, a data communication from the receiver device.

11. The method of wireless power transmission of claim 10 , wherein detecting a change in the power signal comprises detecting a change in the amount of power drawn by the receive antenna.

12. The method of wireless power transmission of claim 10 , wherein the change in the power signal supplied to the amplifier comprises an indication of a change in impedance of the receive antenna, presented to the transmit antenna and caused by an operation of the receiver device.

13. The method of wireless power transmission of claim 10 , wherein the data communication comprises a power requirement of the receiver device related to charging a load of the receiver device.

14. The method of wireless power transmission of claim 10 , wherein the data communication comprises a request for an adjustment of level of power requirement of a load of the receiver device.

15. The method of wireless power transmission of claim 10 , further comprising: generating a transmit modulation signal.

16. The method of wireless power transmission of claim 15 , wherein the modulation signal corresponds to a data communication to be communicated to the receiver device via the magnetic field.

17. The method of wireless power transmission of claim 15 , further comprising:
applying the first signal to the transmit antenna when the transmit modulation signal is in a first state, and
applying a second signal to the transmit antenna when the transmit modulation signal is in a second state.

18. A wireless power transmitter comprising:
means for generating a magnetic field for coupling a charging power in a near-field of the magnetic field to a receive antenna electrically coupled to a receiver device;
means for applying a first signal to the means for generating the magnetic field;
means for supplying a power signal to the means for applying the first signal;
means for detecting a change in the power signal;
means for generating a receive signal responsive to the change in the power signal; and
means for identifying, from the receive signal, a data communication from the receiver device.

19. The wireless power transmitter of claim 18 , wherein the means for detecting a change in the power signal comprises means for detecting a change in the amount of power drawn by the receive antenna.

20. The wireless power transmitter of claim 18 , wherein the data communication comprises a power requirement of the receiver device.

Assignees

• Qualcomm Inc

Inventors

• Toncich Stanley Slavko
• Von Novak Iii William Henry

Classifications

• G06K7/0008 Primary

  General problems related to the reading of electronic memory record carriers, independent of its reading method, e.g. power transfer · CPC title

• H02J7/42

  with electronic devices having internal batteries, e.g. mobile phones · CPC title

• H01F38/14

  Inductive couplings {(for wireless supply or distribution of electric power using inductive coupling H02J50/10)} · CPC title

• H01Q1/38

  formed by a conductive layer on an insulating support {(patch antennas H01Q9/0407; microstrip dipole antennas H01Q9/065; microstrip slot antennas H01Q13/106; transmission line microstrip antennas H01Q13/206; manufacturing reflecting surfaces using insulating material for supporting the reflecting surface  H01Q15/142)} · CPC title

• H01Q1/2225

  used in active tags, i.e. provided with its own power source or in passive tags, i.e. deriving power from RF signal · CPC title