NEAR FIELD TRANSMITTERS FOR WIRELESS POWER CHARGING

• US 20170187228A1
• Filed: 02/17/2016
• Published: 06/29/2017
• Est. Priority Date: 12/24/2015
• Status: Active Grant

• Current Assignee: Energous Corporation
• Original Assignee: Energous Corporation
• Inventors: LEABMAN, Michael A., HOSSEINI, Alister
• Granted Patent: US 10,135,286 B2
• Time in Patent Office: Days
• CPC Class Codes: H02J 50/20 using microwaves or radio frequency waves
• 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: H02J 7/0042 characterised by the mechanical construction
• CPC Class Codes: H04B 5/79 for data transfer in combination with power transfer
• CPC Class Codes: H04W 8/005 Discovery of network devices, e.g. terminals

Abstract

Disclosed is a system including RF circuitry configured to generate an RF signal; a plurality of unit cells configured to receive the RF signal and to cause an RF energy signal having a center frequency to be present within the unit cells; and receiver circuitry configured to charge an electronic device in response to an antenna of the electronic device receiving the RF energy signal when the antenna is tuned to the center frequency and positioned in a near-field distance from one or more of the unit cells.

Claims

1. A method for charging an electronic device, the method comprising:

applying an RF signal to a plurality of unit cells of a charging surface to cause an RF energy signal to be present within the unit cells of the charging surface;

receiving the RF energy signal at an antenna of a wireless device when the antenna is positioned in a near-field distance from at least one of the unit cells; and

charging a battery of the electronic device in response to the antenna receiving the RF energy signal.

2. The method of claim 1, further comprising leaking, by at least one of the unit cells, the RF energy signal to the antenna of the electronic device.

3. The method of claim 2, wherein the RF energy signal operates at a center frequency and wherein leaking the RF energy signal includes leaking, by the at least one of the unit cells, the RF energy signal when the antenna is tuned to the center frequency and positioned in the near-field distance from the at least one of the unit cells.

4. The method of claim 1, wherein the RF energy signal operates at a center frequency and is received at the antenna when the antenna is tuned to the center frequency.

5. The method of claim 1, wherein the near-field distance is less than about 4 mm.

6. The method of claim 1, wherein the electronic device rectifies the received RF energy signal prior to the battery being charged.

7. The method of claim 1, wherein the charging surface includes a metamaterial.

8. The method of claim 1, wherein the RF energy signal operates at a center frequency and the unit cells of the charging surface are configured to retain the RF energy signal when no antenna tuned to the center frequency is positioned within the near-field distance from the at least one of the unit cells.

9. The method of claim 1, wherein applying the RF signal includes generating the RF energy signal using a patch antenna.

10. The method of claim 9, further comprising retaining the RF energy signal in one or more of the unit cells of the charging surface.

11. The method of claim 10, further comprising leaking, by at least one of the unit cells, the RF energy signal through an aperture positioned in the at least one of the unit cells.

12. The method of claim 1, wherein receiving the RF energy signal at an antenna includes receiving the RF energy signal at an antenna externally located from the electronic device.

13. A system comprising:

RF circuitry configured to generate an RF signal;

a charging surface comprising a plurality of unit cells configured to receive the RF signal and to cause an RF energy signal to be present within the unit cells; and

receiver circuitry configured to charge an electronic device in response to an antenna of the electronic device receiving the RF energy signal when the antenna is positioned in a near-field distance from one or more of the unit cells.

14. The system of claim 13, wherein the RF energy signal operates at a center frequency and the unit cells of the charging surface are configured to leak the RF energy signal to the antenna of the electronic device when the antenna is tuned to the center frequency.

15. The system of claim 13, wherein the near-field distance is less than about 4 mm.

16. The system of claim 13, wherein the receiver circuitry includes a rectifier circuit configured to rectify the received RF energy signal.

17. The system of claim 13, wherein the RF circuitry includes one or more patch antennas.

18. The system of claim 13, wherein the charging surface includes a metamaterial.

19. The system of claim 13, wherein each unit cell includes a first substrate layer having a patch antenna and a second substrate layer having an aperture.

20. The system of claim 13, wherein each unit cell includes a first substrate layer having a patch antenna and an aperture positioned substantially around a perimeter of the patch antenna.

21. The system of claim 13, wherein the RF energy signal operates at a center frequency and each unit cell is configured to retain the RF energy signal when no antenna tuned to the center frequency is positioned within the near-field distance from the unit cell.

22. The system of claim 13, wherein the antenna is externally located from the electronic device.