Portable wireless charging pad

• US 9,812,890 B1
• Filed: 12/30/2014
• Issued: 11/07/2017
• Est. Priority Date: 07/11/2013
• Status: Active Grant

• Current Assignee: Energous Corporation
• Original Assignee: Energous Corporation
• Inventors: Leabman, Michael A., Brewer, Gregory Scott
• Primary Examiner(s): Siek, Vuthe
• Application Number:
  US14/585,341
• Time in Patent Office: 1,043 Days
• Field of Search: 320108
• CPC Class Codes: H02J 50/10 using inductive coupling
• CPC Class Codes: H02J 50/20 using microwaves or radio frequency waves
• CPC Class Codes: H02J 50/402 the two or more transmitting or the two or more receiving devices being integrated in the same unit, e.g. power mats with several coils or antennas with several sub-antennas
• 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 7/0042 characterised by the mechanical construction
• CPC Class Codes: H02J 7/04 Regulation of charging current or voltage

Abstract

The present disclosure provides a method and apparatus for improved wireless charging pads for charging and/or powering electronic devices. Such pads may not require a power chord for connecting to a main power supply, for example a wall outlet. In contrast, power may be delivered wireless to the foregoing pads through pocket-forming. A transmitter connected to a power source may deliver pockets of energy to the pads which through at least one embedded receiver may convert such pockets of energy to power. Lastly, the pads may power and/or charge electronic devices through suitable wireless power transmission techniques such as magnetic induction, electrodynamics induction or pocket-forming.

Claims

1. A method for wireless charging, the method comprising:

receiving, by at least one receiver antenna of a near-field cordless charging pad, energy from a first pocket of energy formed from constructive interference of a first plurality of power waves emitted from a first plurality of transmitter antennas of a far-field wireless power transmitter that is distinct from the near-field cordless charging pad;

charging, using the energy received by the at least one receiver antenna from the first pocket of energy, a first battery of the near-field cordless charging pad; and

transmitting, by a second plurality of transmitter antennas of the near-field cordless charging pad that is powered by the first battery, a second plurality of power waves to constructively interfere to form a second pocket of energy at a receiver, wherein the receiver is configured to convert energy of the second pocket of energy to charge a second battery of an electronic device that is coupled with the receiver, wherein the near-field cordless charging pad is in proximity of the electronic device.

2. The method of claim 1, wherein an additional receiver coupled to the at least one receiver antenna of the near-field cordless charging pad and the far-field wireless power transmitter coupled to the first plurality of transmitter antennas communicate to control the charging of the first battery of the near-field cordless charging pad.

3. The method of claim 1, wherein the receiver communicates a power level of the second battery of the electronic device to the near-field cordless charging pad.

4. The method of claim 1, wherein:

the electronic device is a first electronic device, and

the second plurality of transmitter antennas wirelessly charges a second electronic device by transmitting a third plurality of power waves that converge to form a third pocket of energy based on the second device being in proximity of the near-field cordless charging pad.

5. The method of claim 1, wherein the near-field cordless charging pad comprises a perimeter, a surface, and the at least one receiver antenna is included in an antenna array disposed about at least one of the perimeter and the surface.

6. The method of claim 1, wherein the near-field cordless charging pad authenticates the electronic device for wireless charging from the near-field cordless charging pad in response to a request for power from the electronic device via a communications channel according to a wireless communications protocol, wherein the wireless communications protocol is selected from the group consisting of:

Bluetooth, infrared, Wi-Fi, and a frequency modulation (FM) radio signal.

13. The method of claim 1, further comprising:

searching, by the near-field cordless charging pad, for a wireless charging request sent from the electronic device;

initiating, by the near-field cordless charging pad, wireless charging of the electronic device by transmitting the second plurality of power waves that constructively interfere to form the second pocket of energy; and

ceasing, by the near-field cordless charging pad, the wireless charging when at least one of a predetermined charge criterion is met and the electronic device is out of range from the near-field cordless charging pad.

14. The method of claim 13, wherein the near-field cordless charging pad is shaped as a generally flat rectangular box with the second plurality of transmitter antennas positioned around a perimeter of the box.

7. A method for wireless charging comprising:

receiving, by at least one receiver antenna of a near-field cordless charging pad, energy from a first pocket of energy defined via constructive interference of a first plurality of wireless power transmission waves emitted by a first plurality of transmitter antennas of a far-field wireless power transmitter that is distinct from the near-field cordless charging pad, wherein the near-field cordless charging pad comprises a first battery coupled to the at least one receiver antenna;

charging, using energy received by the at least one receiver antenna from the first pocket of energy, the first battery of the near-field cordless charging pad;

transmitting, by a second transmitter of the near-field cordless charging pad that is powered by the first battery, a second plurality of power transmission waves to constructively interfere to form a second pocket of energy at an electronic device, wherein the electronic device is configured to convert energy of the second pocket of energy to charge a second battery of the electronic device when the electronic device is in proximity of the near-field cordless charging pad; and

communicating, by the near-field cordless charging pad, a power level of the first battery to the far-field wireless power transmitter so that the far-field wireless power transmitter can adjust the first pocket of energy based on the power level of the first battery.

8. The method of claim 7, wherein the electronic device comprises a receiver,

wherein the near-field cordless charging pad decodes a signal from the receiver, identifies at least one of a gain of the signal and a phase of the signal, and determines a proximity of the receiver to the near-field cordless charging pad based on at least one of the gain and the phase, and

wherein the near-field cordless charging pad controls transmission of the second plurality of power transmission waves by adjusting respective gains and phases of the second plurality of power transmission waves based on the proximity of the electronic device to the second transmitter.

9. The method of claim 8, wherein the second transmitter of the near-field cordless charging pad and the electronic device are at most about fifteen feet apart from each other when the second battery of the electronic device is charged via energy extracted from the second pocket of energy.

10. The method of claim 7, wherein the near-field cordless charging pad is shaped in a generally flat rectangular shape and sized about two inches by about four inches.

11. The method of claim 10, wherein the near-field cordless charging pad comprises a surface, and wherein a receiver coupled to the at least one receiver antenna of the near-field cordless charging pad comprises a plurality of antenna elements arranged in a generally flat configuration on the surface.

12. The method of claim 10, wherein the near-field cordless charging pad comprises a top surface, and wherein a receiver coupled to the at least one receiver antenna of the near-field cordless charging pad comprises a plurality of antenna elements arranged on the top surface so that the antenna elements are able to interface with the first pocket of energy within about a fifteen foot range from the first transmitter.

15. A device for wireless charging, the device comprising:

a near-field cordless charging pad;

a plurality of receiver antenna elements disposed on a surface of the near-field cordless charging pad, wherein the plurality of receiver antenna elements are configured to interface with a first pocket of energy formed by constructive interference of a first plurality power transmission waves, wherein the first plurality of power transmission waves are transmitted by a far-field wireless power transmitter that is distinct form the near-field cordless charging pad;

a first battery coupled to the near-field cordless charging pad;

a receiver coupled to the near-field cordless charging pad, to the first battery, and to the plurality of receiver antenna elements, wherein the receiver is configured to charge the first battery via the plurality of receiver antenna elements receiving energy from the first pocket of energy; and

a transmitter coupled to the pad and powered by the first battery, wherein the transmitter has a plurality of transmitter antenna elements configured to transmit a second plurality of power transmission waves to constructively interfere to form a second pocket of energy at an electronic device so that a second battery of the electronic device can be charged via energy from the second pocket of energy.

16. The device of claim 15, wherein the transmitter is configured to receive a charging request from the electronic device through at least one of a short RF wave and a pilot signal.

17. The device of claim 15, wherein the transmitter is configured to receive a charging request through a communications functionality selected from the group consisting:

a Bluetooth functionality, a Wi-Fi functionality, a Zigbee functionality, and a FM radio signal functionality.