Smart RF Lensing: Efficient, Dynamic And Mobile Wireless Power Transfer

• US 20180233963A1
• Filed: 04/12/2018
• Published: 08/16/2018
• 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 11,616,401 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 device configured to be powered by electromagnetic waves radiated by a first plurality of radiators forming an RF lens, said wireless device being further configured to respond to the electromagnetic waves to enable tracking of a positon of the wireless device by the plurality of radiators.

2. The wireless device of claim 1 wherein said wireless device further comprises:

a rectifier to rectify the received power to a DC voltage; and

a regulator to regulate the DC voltage.

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

4. The wireless device of claim 1 wherein phases of the electromagnetic waves are dynamically changed in response to movement of the wireless device.

5. The wireless device of claim 1 wherein each of the first plurality of radiators comprises an associated locked-loop circuit locked to a same reference signal.

6. The wireless device of claim 5 wherein each locked-loop circuit is configured to vary a phase of the electromagnetic wave radiated by the locked-loop circuit'"'"'s associated radiator.

7. The wireless device of claim 5 wherein each locked-loop circuit is configured to vary of an amplitude of the electromagnetic wave radiated by the locked-loop circuit'"'"'s associated radiator.

8. The wireless device of claim 5 wherein each locked-loop circuit is configured to vary a frequency of the electromagnetic wave radiated by the locked-loop circuit'"'"'s associated radiator.

9. The wireless device of claim 5 wherein each locked-loop circuit is configured to vary a polarization of the electromagnetic wave radiated by the locked-loop circuit'"'"'s associated radiator.

10. The wireless device of claim 1 wherein said RF lens is further adapted to power a second wireless device concurrently with the first device.

11. The wireless device of claim 1 wherein said wireless device and RF lens are positioned indoor.

12. The wireless device of claim 1 wherein each of the first plurality of radiators comprises a programmable delay element.

13. The wireless device of claim 1 wherein the first plurality of radiators form a one-dimensional array of radiators.

14. The wireless device of claim 1 wherein the first plurality of radiators form a two-dimensional array of radiators.

15. The wireless device of claim 1 wherein the first plurality of radiators form a first tile adapted to be positioned adjacent a second tile comprising a second plurality of radiators, said first and second tiles being in electrical communication with one another and operating in concert to radiate electromagnetic waves to power the wireless device.

16. The wireless device of claim 1 wherein a position of the wireless device is tracked in accordance with an estimation algorithm.

17. The wireless device of claim 1 wherein a position of the wireless device is tracked in accordance with a travel time of the electromagnetic waves radiated from the RF lens to the wireless device and a travel time of a response signal transmitted by the wireless device to the RF lens.

18. The wireless device of claim 1 wherein a position of the first device is tracked using a signal selected from a group consisting of WiFi and GPS signals.

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

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

21. The wireless device of claim 1 wherein phases of the first plurality of locked-loop circuits are further selected to enable electromagnetic waves scattered off objects to power the wireless device.

22. The wireless device of claim 1 wherein the RF lens further comprise a receiver configured to receive electromagnetic waves reflected off objects due to scattering.

23. The wireless device of claim 1 wherein said first plurality of radiators operate at substantially a same frequency.

24. The wireless device of claim 23 wherein a phase of the electromagnetic wave radiated by at least a first one of the first plurality of radiators is varied.

25. The wireless device of claim 1 wherein said wireless device periodically sends information about the power it receives to the RF lens.

26. The wireless device of claim 15 wherein said first plurality of radiators and said second plurality of radiators operate at substantially a same frequency.