TRANSMIT POWER CONTROL FOR A WIRELESS CHARGING SYSTEM

• US 20090284369A1
• Filed: 10/10/2008
• Published: 11/19/2009
• Est. Priority Date: 05/13/2008
• Status: Abandoned Application

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Von Novak, William H., Toncich, Stanley Slavko
• Application Number:
  US12/249,861
• Publication Number:
  US 20090284369A1
• Time in Patent Office: Days
• US Class Current: 340/539.300
• CPC Class Codes: G06K 19/0701 at least one of the integrated circuit chips comprising an arrangement for power management
• CPC Class Codes: G06K 19/0715 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 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 7/10178 including auxiliary means for focusing, repeating or boosting the electromagnetic interrogation field comparable booster antennas integrated on the record carrier itself G06K19/07794
• CPC Class Codes: H01F 38/14 Inductive couplings for wireless supply or distribution of electric power using inductive coupling H02J50/10
• CPC Class Codes: H01Q 1/2225 used in active tags, i.e. provided with its own power source or in passive tags, i.e. deriving power from RF signal
• CPC Class Codes: H01Q 1/38 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 Class Codes: H01Q 7/00 Loop antennas with a substantially uniform current distribution around the loop and having a directional radiation pattern in a plane perpendicular to the plane of the loop
• CPC Class Codes: H02J 50/005 Mechanical details of housing or structure aiming to accommodate the power transfer means, e.g. mechanical integration of coils, antennas or transducers into emitting or receiving devices
• 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 50/50 using additional energy repeaters between transmitting devices and receiving devices
• CPC Class Codes: H02J 50/502 the energy repeater being integrated together with the emitter or the receiver
• CPC Class Codes: H02J 50/60 responsive to the presence of foreign objects, e.g. detection of living beings
• CPC Class Codes: H02J 50/80 involving the exchange of data, concerning supply or distribution of electric power, between transmitting devices and receiving devices
• CPC Class Codes: H02J 50/90 involving detection or optimisation of position, e.g. alignment
• CPC Class Codes: H02J 7/00034 Charger exchanging data with an electronic device, i.e. telephone, whose internal battery is under charge
• CPC Class Codes: H04B 5/0031 for data transfer
• CPC Class Codes: H04B 5/0037 : for power transfer
• CPC Class Codes: H04B 5/02 : using transceiver
• CPC Class Codes: H04B 5/48 : Transceivers
• 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

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. A load sensing circuit coupled to an amplifier driving the transmit antenna can detect a change in power consumed by the amplifier in response to the energy extracted by the receive antenna. The transmit antenna adjusts to a high-power charging mode when one or more receivers are present in the coupling-mode region and adjusts to a low-power beacon mode when there are no receivers in the coupling-mode region.

Claims

1. A method of wireless power transfer, comprising:

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 at a low-power beacon mode;

responding to the low-power beacon mode with a receiver response comprising consuming power from the electromagnetic field with a receive antenna operating substantially near the resonant frequency in the coupling-mode region;

detecting the receiver response to the low-power beacon mode by detecting a difference in power supplied to the electromagnetic field during the receiver response relative to before the receiver response;

generating the electromagnetic field at a high-power charging mode responsive to the receiver response.

2. The method of claim 1, further comprising consuming power from the electromagnetic field with at least one additional receive antenna operating substantially near the resonant frequency in the coupling-mode region, wherein at least some of the power in the electromagnetic field is consumed by the receive antenna and at least some of the power in the electromagnetic field is consumed by the at least one additional receive antenna.

3. The method of claim 1, further comprising:

modifying the receiver response by substantially diminishing the amount of power consumed from the electromagnetic field by the receive antenna;

detecting the modified receiver response by detecting a difference in power supplied to the electromagnetic field during the modified receiver response relative to the receiver response; and

returning the electromagnetic field to the low-power beacon mode responsive to the modified receiver response.

4. The method of claim 3, wherein modifying the receiver response comprises an act selected from the group consisting of removing power from the receive antenna, removing the receive antenna from the coupling-mode region, and cloaking the receive antenna by modifying the resonant frequency of the receive antenna.

5. The method of claim 1, further comprising communicating a presence of the receive antenna operating substantially near the resonant frequency in the coupling-mode region, the communicating occurring between a receiver operably coupled to the receive antenna and a transmitter operably coupled to the transmit antenna by a wireless channel different from a wireless channel of the transmit antenna.

6. A system for wireless power transfer, comprising:

means for 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 at a low-power beacon mode;

means for responding to the low-power beacon mode with a receiver response comprising consuming power from the electromagnetic field with a receive antenna operating substantially near the resonant frequency in the coupling-mode region;

means for detecting the receiver response to the low-power beacon mode by detecting a difference in power supplied to the electromagnetic field during the receiver response relative to before the receiver response;

means for generating the electromagnetic field at a high-power charging mode responsive to the receiver response.

7. The system of claim 6, further comprising means for consuming power from the electromagnetic field with at least one additional receive antenna operating substantially near the resonant frequency in the coupling-mode region, wherein at least some of the power in the electromagnetic field is consumed by the receive antenna and at least some of the power in the electromagnetic field is consumed by the at least one additional receive antenna.

8. The system of claim 6, further comprising:

means for modifying the receiver response by substantially diminishing the amount of power consumed from the electromagnetic field by the receive antenna;

means for detecting the modified receiver response by detecting a difference in power supplied to the electromagnetic field during the modified receiver response relative to the receiver response; and

means for returning the electromagnetic field to the low-power beacon mode responsive to the modified receiver response.

9. The system of claim 8, wherein the means for modifying the receiver response comprises means selected from the group consisting of means for removing power from the receive antenna, means for removing the receive antenna from the coupling-mode region, and means for cloaking the receive antenna by modifying the resonant frequency of the receive antenna.

10. The system of claim 6, further comprising:

means in a receiver operably coupled to the receive antenna for communicating a presence of the receive antenna operating substantially near the resonant frequency in the coupling-mode region; and

means in a transmitter operably coupled to the transmit antenna for receiving the communication;

wherein the communication occurs on a wireless channel different from a wireless channel of the transmit antenna.

11. A wireless power transmitter, comprising:

a transmit antenna for generating a near field radiation within a coupling-mode region for coupling to a receive antenna;

an amplifier for applying an RF signal to the transmit antenna;

a transmit controller operably coupled to the transmit antenna and the amplifier, wherein the transmit controller can adjust a power of the near field radiation between at least a low-power beacon mode and a high-power charging mode by adjusting power to the amplifier.

12. The wireless power transmitter of claim 11, further comprising a load sensing circuit operably coupled to the amplifier and the transmit controller, the load sensing circuit for detecting changes in power consumption by the amplifier.

13. The wireless power transmitter of claim 12, wherein the transmit controller can adjust the power to the amplifier responsive to the detected change in power consumption.

14. The wireless power transmitter of claim 13, wherein the transmit controller:

adjusts the wireless power transmitter to the high-power charging mode when there is an increase in the power consumption during the low-power beacon mode; and

adjusts the wireless power transmitter to the low-power beacon mode when there is a decrease in power consumption during the high-power charging mode.

15. The wireless power transmitter of claim 11, further comprising a wireless communicator operably coupled to the transmit controller, the wireless communicator for communication with a at least one receive device over a wireless channel different from a wireless channel of the transmit antenna.

16. A wireless power receiver, comprising:

a receive antenna configured for coupling with a transmit antenna operating at a resonant frequency through a coupling-mode region generated by the transmit antenna to generate an RF signal;

a switching circuit operably coupled to the receive antenna and configured for operating the wireless power receiver in a power reception state by operating the receive antenna at substantially near the resonant frequency or a cloaking state by operating the receive antenna at a frequency substantially different from the resonant frequency.

17. The wireless power receiver of claim 16, further comprising:

a controller operably coupled to the switching circuit; and

a rectifier operably coupled to the receive antenna, the rectifier for converting the RF signal to a DC signal for supplying power to a receive device;

wherein the controller operates the switching circuit to enable the DC signal to supply power during the power reception state and disable the DC signal from supplying power during the cloaking state.

18. The wireless power receiver of claim 16, further comprising:

a controller operably coupled to the switching circuit; and

a wireless communicator operably coupled to the controller, the wireless communicator for communicating a presence of the wireless power receiver in the coupling-mode region to a transmitter, wherein the communicating is on a wireless channel different from a wireless channel of the transmit antenna;

wherein the controller operates the wireless communicator when the wireless power receiver is in the coupling-mode region.