Portable wireless charging pad

• US 9,800,080 B2
• Filed: 07/21/2015
• Issued: 10/24/2017
• Est. Priority Date: 05/10/2013
• Status: Active Grant

• Current Assignee: Energous Corporation
• Original Assignee: Energous Corporation
• Inventors: Leabman, Michael A., Brewer, Gregory Scott
• Primary Examiner(s): Dunn, Drew A
• Assistant Examiner(s): Zhou, Zixuan
• Application Number:
  US14/804,845
• Publication Number:
  US 20150326063A1
• Time in Patent Office: 826 Days
• Field of Search: 320108, 307104
• 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 cord 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 comprising:

providing a cordless charging pad that includes a wireless power receiver and a wireless power transmitter;

receiving, at the wireless power receiver of the cordless charging pad, energy from a constructive interference pattern formed by convergence of a plurality of radio frequency (RF) waves that are transmitted by a far-field wireless power transmitter, wherein the far-field wireless power transmitter is distinct and separate from the cordless charging pad;

providing power, using the received energy, to the wireless power transmitter of the cordless charging pad; and

wirelessly transmitting power, from the wireless power transmitter of the cordless charging pad, near a surface of the cordless charging pad when a receiver for an electronic device is positioned on top of the surface of the cordless charging pad.

2. The method for wireless charging of claim 1, further comprising authenticating the receiver for the electronic device that is positioned on the surface of the cordless charging pad.

3. The method for wireless charging of claim 2, wherein authenticating comprises confirming via a Wi-Fi communication to a cloud based service that the receiver is entitled to access to energy from the wireless charging pad.

4. The method of claim 1, wherein the plurality of RF waves is phase-shifted by the far-field wireless power transmitter to cause the plurality of RF waves to converge and form the constructive interference pattern.

5. The method of claim 1, wherein the wireless power transmitter of the cordless charging pad wirelessly transmits the power to the receiver for the electronic device while the wireless power transmitter of the cordless charging pad is provided with power using the received energy.

6. The method of claim 1, wherein the power is wirelessly transmitted by transmitting, using at least two antenna elements of the wireless power transmitter, an additional plurality of RF waves that converge to form an additional constructive interference pattern near the surface of the cordless charging pad.

7. The method of claim 6, wherein the additional plurality of RF waves is generated by an RF integrated circuit of the wireless power transmitter of the cordless charging pad, and the additional plurality of RF waves is phase-shifted by the RF integrated circuit of the cordless charging pad to control formation of the additional constructive interference pattern.

8. The method of claim 7, wherein the additional plurality of RF waves is also gain-adjusted by the RF integrated circuit to control formation of the additional plurality of RF waves.

9. The method of claim 1, wherein the power received at the wireless power receiver is converted, by at least one rectifier and at least one power converter, to usable electricity for charging a battery of the cordless charging pad.

10. The method of claim 9, further comprising, after charging the battery of the wireless charging pad, powering the wireless power transmitter of the wireless charging pad using the charged battery.

11. The method of claim 1, further comprising, before wirelessly transmitting the power to the receiver for the electronic device, determine a position of the electronic device, wherein the power is wirelessly transmitted towards the determined position.

12. The method of claim 1, wherein the power is wirelessly transmitted by the wireless power transmitter of the cordless charging pad using inductive elements of the wireless power transmitter of the wireless charging pad.

13. The method of claim 1, wherein the wireless charging pad is embedded within a briefcase.

14. The method of claim 1, wherein the near-field charging pad is embedded within a purse.

15. The method of claim 1, wherein a plurality of receiving antenna elements of the wireless power receiver is separated from a plurality of transmitting antenna elements of the wireless power transmitter.

16. The method of claim 15, wherein the plurality of receiving antenna elements is located around a perimeter of the wireless charging pad.

17. The method of claim 15, wherein the plurality of receiving antenna elements occupies a first portion of the near-field charging pad and the plurality of transmitting antenna elements occupies a second portion of the charging, and the first and second portions are non-overlapping.

18. A cordless charging pad comprising:

a wireless power receiver configured to;

receive energy from a constructive interference pattern formed by convergence of a plurality of radio frequency (RF) waves that are transmitted by a far-field wireless power transmitter, wherein the far-field wireless power transmitter is distinct and separate from the cordless charging pad; and

provide power, using the received energy, to a wireless power transmitter of the charging pad; and

the wireless power transmitter configured to wirelessly transmit power near a surface of the charging pad when a receiver for an electronic device is positioned on top of the surface of the cordless charging pad.