SIGNALING CHARGING IN WIRELESS POWER ENVIRONMENT

• US 20090286475A1
• Filed: 10/10/2008
• Published: 11/19/2009
• Est. Priority Date: 05/13/2008
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Von Novak, William H., Toncich, Stanley Slavko
• Granted Patent: US 9,130,407 B2
• Time in Patent Office: Days
• US Class Current: 455/41.100
• 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 transmitter to create a coupling-mode region within a near field of the transmitter during a synchronization portion of a time-multiplexed recurring period. During a power transmission portion of the recurring period, the electromagnetic field will continue to be generated when there is a receiver within the coupling-mode region, or the electromagnetic field will be disabled when there are no receivers within the coupling-mode region. Different segments of the power transmission portion are allocated to different receivers. The transmitter issues serial commands to the receivers by on/off keying the electromagnetic field. The receivers issue serial replies by changing the amount of power consumed from the electromagnetic field between two different states. The serial commands and serial replies are used to determine the number of receivers, their power requirements, and the allocation of segments.

Claims

1. A method of wireless power transfer, comprising:

generating an electromagnetic field at a resonant frequency of a transmitter to create a coupling-mode region within a near field of the transmitter during a synchronization portion of a time-multiplexed recurring period; and

during a power transmission portion of the time-multiplexed recurring period;

continuing the generating the electromagnetic field when there is at least one receiver within the coupling-mode region designated to accept power from the electromagnetic field; and

disabling the generating the electromagnetic field when there are no receivers within the coupling-mode region designated to accept power from the electromagnetic field.

2. The method of claim 1, further comprising communicating a serial command from the transmitter to the receiver during the synchronization portion by performing an on/off keying of the electromagnetic field.

3. The method of claim 2, further comprising generating a serial response from the receiver to the transmitter responsive to the serial command during a portion of the time-multiplexed recurring period between the synchronization portion and the power transmission portion by consuming power from the electromagnetic field at two different levels to indicate two different digital states.

4. The method of claim 1, further comprising:

determining when there are a plurality of receivers within the coupling-mode region designated to accept power from the electromagnetic field;

allocating segments of the power transmission portion to each of the plurality of receivers designated to accept power;

communicating the segment allocated to each of the plurality of receivers during the synchronization portion; and

enabling each receiver of the plurality during the segment to which it is allocated.

5. The method of claim 4, further comprising periodically re-allocating the segments of the power transmission portion responsive to an event selected from the group consisting of a new receiver entering the coupling-mode region, a receiver leaving the coupling-mode region, a receiver responding to a serial command requesting a status of the receiver with a change in amount of power requested, and a receiver failing to respond to the serial command requesting the status of the receiver.

6. The method of claim 1, further comprising determining when a new receiver has entered the coupling-mode region by:

issuing a serial command for a new device request during the synchronization portion;

issuing a serial response for a new device reply from the new receiver during a portion of the time-multiplexed recurring period between the synchronization portion and the power transmission portion; and

issuing a serial command for a power segment allocation and a device identification to the new receiver if the new device reply is received correctly.

7. The method of claim 6, wherein the issuing a serial response is performed by more that one new receiver, and further comprising:

detecting that the new device reply was not received correctly;

issuing subsequent new device requests during subsequent recurring periods; and

for each new receiver, waiting a random number of the subsequent new device requests before replying with an additional new device reply.

8. A wireless power transfer system, comprising:

means for generating an electromagnetic field at a resonant frequency of a transmitter to create a coupling-mode region within a near field of the transmitter during a synchronization portion of a time-multiplexed recurring period; and

during a power transmission portion of the time-multiplexed recurring period;

means for continuing the generating the electromagnetic field when there is at least one receiver within the coupling-mode region designated to accept power from the electromagnetic field; and

means for disabling the generating the electromagnetic field when there are no receivers within the coupling-mode region designated to accept power from the electromagnetic field.

9. The system of claim 8, further comprising means for communicating a serial command from the transmitter to the receiver during the synchronization portion by performing an on/off keying of the electromagnetic field.

10. The system of claim 9, further comprising means for generating a serial response from the receiver to the transmitter responsive to the serial command during a portion of the time-multiplexed recurring period between the synchronization portion and the power transmission portion by consuming power from the electromagnetic field at two different levels to indicate two different digital states.

11. The system of claim 8, further comprising:

means for determining when there are a plurality of receivers within the coupling-mode region designated to accept power from the electromagnetic field;

means for allocating segments of the power transmission portion to each of the plurality of receivers designated to accept power;

means for communicating the segment allocated to each of the plurality of receivers during the synchronization portion; and

means for enabling each receiver of the plurality during the segment to which it is allocated.

12. The system of claim 11, further comprising means for periodically re-allocating the segments of the power transmission portion responsive to an event selected from the group consisting of a new receiver entering the coupling-mode region, a receiver leaving the coupling-mode region, a receiver responding to a serial command requesting a status of the receiver with a change in amount of power requested, and a receiver failing to respond to the serial command requesting the status of the receiver.

13. The system of claim 8, further comprising means for determining when a new receiver has entered the coupling-mode region by:

issuing a serial command for a new device request during the synchronization portion;

issuing a serial response for a new device reply from the new receiver during a portion of the time-multiplexed recurring period between the synchronization portion and the power transmission portion; and

issuing a serial command for a power segment allocation and a device identification to the new receiver if the new device reply is received correctly.

14. The system of claim 13, wherein the issuing a serial response is performed by more that one new receiver, and further comprising:

means for detecting that the new device reply was not received correctly;

means for issuing subsequent new device requests during subsequent recurring periods; and

for each new receiver, means for waiting a random number of the subsequent new device requests before replying with an additional new device reply.

15. 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, wherein the transmit controller;

determines a time-multiplexed power allocation within a recurring period for each of a plurality of receive devices disposed within the coupling-mode region; and

communicates the time-multiplexed power allocation to each of the plurality of receive devices.

16. The wireless power transmitter of claim 15, further comprising a wireless communicator operably coupled to the transmit controller, the wireless communicator for communication with the plurality of receive devices over a wireless channel different from a wireless channel of the transmit antenna, wherein the transmit controller communicates the time-multiplexed power allocation through the wireless channel.

17. The wireless power transmitter of claim 15, further comprising a transmit modulation signal operably coupled to the amplifier and the transmit controller, wherein the transmit controller communicates the time-multiplexed power allocation by operating the transmit modulation signal so the amplifier applies the RF signal to the transmit antenna when the transmit modulation signal is in a first state and applies a DC signal to the transmit antenna when the transmit modulation signal is in a second state.

18. The wireless power transmitter of claim 15, further comprising a controller operably coupled to the transmit controller and the amplifier, the controller for:

enabling the amplifier to apply the RF signal to the transmit antenna to generate the near field radiation during a synchronization portion of a time-multiplexed recurring period; and

during a power transmission portion of the time-multiplexed recurring period;

continuing the enabling the amplifier when there is at least one receiver within the coupling-mode region designated to accept power from the near field radiation; and

disabling the amplifier from applying the RF signal to the transmit antenna when there are no receivers within the coupling-mode region designated to accept power from near field radiation.

19. The wireless power transmitter of claim 18, wherein the controller if further for:

generating a serial command from the transmitter to the receiver during the synchronization portion by performing an on/off keying of the near field radiation by enabling/disabling the amplifier.

20. The wireless power transmitter of claim 19, further comprising:

a load sensing circuit operably coupled to the amplifier and the controller, the load sensing circuit for detecting changes in power consumption by the amplifier and generating a serial response signal to the controller responsive to the changes in power consumption; and

the controller is further for decoding the serial response to determine at least one of a presence of a new receiver in the coupling-mode region or a status of an existing receiver in the coupling-mode region.

21. A wireless power receiver, comprising:

a receive antenna configured for coupling with a transmit antenna through a near field radiation 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 first power reception state consuming a first power amount from the near field radiation and a second power reception state consuming a second power amount from the near field radiation; and

a controller operably coupled to the switching circuit, the controller for generating a serial response on the receive antenna by controlling the switching circuit to enter the either the first power reception state or the second power reception state for each bit of the serial response.

22. The wireless power receiver of claim 21, further comprising a signal extractor operably coupled to the RF signal and the controller, the signal extractor for detecting an on/off keying modulation of the near field radiation to extract a serial command responsive to the on/off keying modulation.

23. The wireless power receiver of claim 21, further comprising 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 is further for:

detecting a synchronization portion of a time-multiplexed recurring period from the near field radiation; and

enabling the rectifier during a power transmission portion of the time-multiplexed recurring period that is allocated to the wireless power receiver.