SMART RF LENSING: EFFICIENT, DYNAMIC AND MOBILE WIRELESS POWER TRANSFER

• US 20180226841A1
• Filed: 03/30/2018
• Published: 08/09/2018
• Est. Priority Date: 11/09/2012
• Status: Active Grant

• Current Assignee: California Institute of Technology
• Original Assignee: California Institute of Technology
• Inventors: Sengupta, Kaushik, Hajimiri, Seyed Ali
• Granted Patent: US 11,502,552 B2
• Time in Patent Office: Days
• CPC Class Codes: H01Q 21/225 Finite focus antenna arrays
• CPC Class Codes: H02J 50/20 using microwaves or radio frequency waves
• CPC Class Codes: H02J 50/23 characterised by the type of transmitting antennas, e.g. directional array antennas or Yagi antennas
• CPC Class Codes: H02J 50/40 using two or more transmitting or receiving devices H02J50/50 takes precedence
• 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 50/60 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

Abstract

An RF lens includes a multitude of radiators adapted to transmit radio frequency electromagnetic EM waves whose phases are modulated so as to concentrate the radiated power in a small volume of space in order to power an electronic device positioned in that space. Accordingly, the waves emitted by the radiators are caused to interfere constructively at that space. The multitude of radiators are optionally formed in a one-dimensional or two-dimensional array. The electromagnetic waves radiated by the radiators have the same frequency but variable amplitudes.

Claims

1. A wireless charger comprising:

a first tile comprising a first plurality of radiators configured to radiate electromagnetic waves; and

a second tile comprising a second plurality of radiators configured to radiate electromagnetic waves, wherein said first and second tiles are adapted to be positioned adjacent one another so as to operate in concert and wirelessly power a first device positioned away from the wireless charger.

2. The wireless charger of claim 1 wherein the first tile is adapted to charge a second device concurrently with the first device.

3. The wireless charger of claim 1 wherein said first tile, said second tile, and said first device are positioned indoor.

4. The wireless charger of claim 1 wherein said first device is retro-fitted externally with components to receive the electromagnetic waves.

5. The wireless charger of claim 1 further comprising third and fourth tiles each comprising a plurality of radiators adapted to radiate electromagnetic waves to power the first device, wherein said first, second, third and fourth tiles form a one dimensional array of tiles.

6. The wireless charger of claim 1 further comprising third and fourth tiles each comprising a plurality of radiators adapted to radiate electromagnetic waves to power the first device, wherein said first, second, third and fourth tiles form a two dimensional array of tiles.

7. The wireless charger of claim 5 wherein said first, second, third and fourth tiles are in electrical communication with one another.

8. The wireless charger of claim 1 wherein said first tile comprises a first plurality of locked-loop circuits each associated with a different one of the first plurality of radiators, and said second tile comprises a second plurality of locked-loop circuits each associated with a different one of the second plurality of radiators, wherein said first and second plurality of locked-loop circuits are locked to a same reference signal.

9. The wireless charger of claim 1 wherein each of said first and second plurality of radiators comprises a receiver to receive a signal transmitted by the first device.

10. The wireless charger of claim 1 wherein each of said first and second tiles comprises one or more receivers configured to receive a signal transmitted by the first device.

11. The wireless charger of claim 10 wherein said first and second tiles are configured to track a position of the first device using the signal transmitted by the first device.

12. The wireless charger of claim 1 wherein said wireless charger comprises a control circuit configured to dynamically change phases of the electromagnetic waves generated by the first and second plurality of radiators in response to movements by the first device.

13. The wireless charger of claim 1 wherein a frequency of the electromagnetic waves radiated by the first and second plurality of radiators is selected from a group consisting of 5.8 GHz, 10 GHz, and 24 GHz.

14. The wireless charger of claim 1 wherein a wavelength of the electromagnetic waves radiated by the first and second plurality of radiators is in mm-wave band.

15. The wireless charger of claim 8 wherein a frequency of the electromagnetic waves radiated by the first and second plurality of radiators is different from a frequency of the reference signal.

16. The wireless charger of claim 1 wherein each of the first and second plurality of radiators comprises a programmable delay element.

17. The wireless charger of claim 11 wherein the position of the first device is tracked in accordance with an estimation algorithm.

18. The wireless charger of claim 11 wherein the position of the first device is tracked in accordance with a travel time of the electromagnetic waves transmitted from the wireless charger to the first device and a travel time of a response signal transmitted by the first device.

19. The wireless charger of claim 11 wherein the position of the first device is tracked using a signal selected from a group consisting of WiFi and GPS signals.

20. The wireless charger of claim 8 wherein phases of the first and second plurality of locked-loop circuits are further selected to enable electromagnetic waves scattered off objects to power the first device.

21. The wireless charger of claim 10 wherein the signal transmitted by the first device includes data representative of a power received by the first device.

22. The wireless charger of claim 8 wherein each of said first and second plurality of locked-loop circuits is configured to vary of a phase of the electromagnetic wave transmitted by an associated radiator.

23. The wireless charger of claim 8 wherein each of said first and second plurality of locked-loop circuits is configured to vary of an amplitude of the electromagnetic wave transmitted by an associated radiator.

24. The wireless charger of claim 8 wherein each of said first and second plurality of locked-loop circuits is configured to vary of a frequency of the electromagnetic wave transmitted by an associated radiator.

25. The wireless charger of claim 8 wherein each of said first and second plurality of locked-loop circuits is configured to vary of a polarization of the electromagnetic wave transmitted by an associated radiator.

26. The wireless charger of claim 9 wherein each receiver is configured to receive electromagnetic waves reflected off objects due to scattering.