Reconfigurable electromagnetic surface of pixelated metal patches

• US 9,972,905 B2
• Filed: 02/09/2015
• Issued: 05/15/2018
• Est. Priority Date: 01/09/2013
• Status: Active Grant

• Current Assignee: HRL Laboratories LLC (The Boeing Co.)
• Original Assignee: HRL Laboratories LLC (The Boeing Co.)
• Inventors: Schaffner, James H., Song, Hyok J., Sayyah, Keyvan R., Patterson, Pamela R., Moon, Jeong-Sun, Reamon, Alan E., Kona, Keerti S., Colburn, Joseph S.
• Primary Examiner(s): Munoz, Daniel J
• Application Number:
  US14/617,361
• Publication Number:
  US 20160013549A1
• Time in Patent Office: 1,191 Days
• CPC Class Codes: H01Q 1/06 Means for the lighting or illuminating of antennas, e.g. for purpose of warning
• CPC Class Codes: H01Q 15/0026 said selective devices having a stacked geometry or having multiple layers
• CPC Class Codes: H01Q 19/005 Patch antenna using one or more coplanar parasitic elements
• CPC Class Codes: H01Q 21/0093 Monolithic arrays
• CPC Class Codes: H01Q 21/065 Patch antenna array
• CPC Class Codes: H01Q 3/01 varying the shape of the antenna or antenna system
• CPC Class Codes: H01Q 3/2676 Optically controlled phased array
• CPC Class Codes: H01Q 3/46 Active lenses or reflecting arrays
• CPC Class Codes: H01Q 9/0407 Substantially flat resonant element parallel to ground plane, e.g. patch antenna dipole H01Q9/285; monopole H01Q9/40

Abstract

A reconfigurable electro-magnetic tile includes a laser layer including a plurality of lasers, and a pixelated surface comprising a plurality of metal patches and a plurality of switches, wherein each respective switch of the plurality of switches is in a gap between a first respective metal patch and a second respective metal patch, wherein each respective switch is optically coupled to at least one respective laser of the plurality of lasers, and wherein each switch of the plurality of switches comprises a phase change material.

Claims

1. A reconfigurable electro-magnetic tile comprising:

a laser layer comprising a plurality of lasers, wherein the laser layer has a height;

a pixelated surface comprising a plurality of metal patches and a plurality of switches, wherein each respective switch of the plurality of switches is in a gap between a first respective metal patch and a second respective metal patch; and

a ground plane between the laser layer and the pixelated surface, wherein the ground plane is above the laser layer and does not intersect any portion of the height of the laser layer, wherein the ground plane comprises a frequency selective surface, wherein the ground plane has a plurality of pin holes, each pin hole extending entirely through the ground plane, wherein each respective pin hole allows light from at least one respective laser of the plurality of lasers to be transmitted through the ground plane to a respective switch, and wherein at least one respective laser of the plurality of lasers transmits light that passes through at least one respective pin hole;

wherein each respective switch is optically coupled to at least one respective laser of the plurality of lasers;

wherein each switch of the plurality of switches comprises a phase change material;

wherein the phase change material of a respective switch changes from a non-conducting state to a conducting state when the coupled respective laser lases a first power density of light on the phase change material of the respective switch; and

wherein the phase change material of a respective switch changes from a conducting state to a non-conducting state when the coupled respective laser lases a second power density of light on the phase change material of the respective switch.

2. The reconfigurable electro-magnetic tile of claim 1 wherein:

the plurality of lasers comprise a plurality of vertical cavity surface emitting lasers (VCSELs).

3. The reconfigurable electro-magnetic tile of claim 1 further comprising:

a plurality of lenses between the laser layer and the pixelated surface;

wherein each respective lens of the plurality of lenses focuses light from a respective laser onto a respective switch.

4. The reconfigurable electro-magnetic tile of claim 3 wherein the plurality of lenses further comprise:

a collimating lens array comprising a first plurality of micro-lenses between the laser layer and the ground plane; and

a focusing lens array comprising a second plurality of micro-lenses between the ground plane and the pixelated surface.

5. The reconfigurable electro-magnetic tile of claim 4 further comprising:

an optically transparent substrate between the ground plane and the focusing lens array;

wherein the optically transparent substrate comprises glass, fused silica, quartz, an optically transparent plastic, or GaAs.

6. The reconfigurable electro-magnetic tile of claim 1:

wherein the ground plane shields the pixelated surface from radio frequency interference from control lines for the plurality of lasers.

7. The reconfigurable electro-magnetic tile of claim 1 further comprising:

a plurality of transmit/receive modules, each transmit/receive module coupled by an electrical conductor to at least one metal patch of the plurality of metal patches;

wherein the laser layer is between the plurality of transmit/receive modules and the pixelated surface.

8. The reconfigurable electro-magnetic tile of claim 1 wherein the phase change material comprises:

germanium-telluride (GeTe) doped chalcogenide glass.

9. The reconfigurable electro-magnetic tile of claim 1 wherein the ground plane comprises:

a multiple-layer frequency selective reflector.

10. The reconfigurable electro-magnetic tile of claim 1 wherein the phase change material has an aspect ratio such that a width of the phase change material across the gap is substantially less than a length of the phase change material along the gap.

11. The reconfigurable electro-magnetic tile of claim 1 further comprising:

a control and driver circuit for controlling and selectively driving lasers of the plurality of lasers.

12. The reconfigurable electro-magnetic tile of claim 1 wherein the pixelated surface further comprises:

reconfigurable non-driven elements.

13. The reconfigurable electro-magnetic tile of claim 1 wherein:

the metallic patches have dimensions smaller than a wavelength for a desired radio frequency of operation.

14. The reconfigurable electro-magnetic tile of claim 1 wherein a diameter of each pin hole is less than a wavelength for a desired radio frequency of operation.

15. A method of providing a reconfigurable electro-magnetic tile comprising:

providing a laser layer comprising a plurality of lasers, wherein the laser layer has a height;

providing a pixelated surface comprising a plurality of metal patches and a plurality of switches, wherein each respective switch of the plurality of switches is in a gap between a first respective metal patch and a second respective metal patch; and

providing a ground plane between the laser layer and the pixelated surface, wherein the ground plane is above the laser layer and does not intersect any portion of the height of the laser layer, wherein the ground plane comprises a frequency selective surface, wherein the ground plane has a plurality of pin holes, each pin hole extending entirely through the ground plane, wherein each respective pin hole allows light from at least one respective laser of the plurality of lasers to be transmitted through the ground plane to a respective switch, and wherein at least one respective laser of the plurality of lasers transmits light that passes through at least one respective pin hole;

wherein each respective switch is optically coupled to at least one respective laser of the plurality of lasers;

wherein each switch of the plurality of switches comprises a phase change material;

wherein the phase change material of a respective switch changes from a non-conducting state to a conducting state when the coupled respective laser lases a first power density of light on the phase change material of the respective switch; and

wherein the phase change material of a respective switch changes from a conducting state to a non-conducting state when the coupled respective laser lases a second power density of light on the phase change material of the respective switch.

16. The method of claim 15 wherein:

the plurality of lasers comprise a plurality of vertical cavity surface emitting lasers (VCSELs).

17. The method of claim 15 further comprising:

providing a plurality of lenses between the laser layer and the pixelated surface;

wherein each respective lens of the plurality of lenses focuses light from a respective laser onto a respective switch.

18. The method of claim 17 wherein the plurality of lenses further comprise:

a collimating lens array comprising a first plurality of micro-lenses between the laser layer and the ground plane; and

a focusing lens array comprising a second plurality of micro-lenses between the ground plane and the pixelated surface.

19. The method of claim 18 further comprising:

providing an optically transparent substrate between the ground plane and the focusing lens array;

wherein the optically transparent substrate comprises glass, fused silica, quartz, an optically transparent plastic, or GaAs.

20. The method of claim 15:

wherein the ground plane shields the pixelated surface from radio frequency interference from control lines for the plurality of lasers.

21. The method of claim 15 further comprising:

providing a plurality of transmit/receive modules, each transmit/receive module coupled by an electrical conductor to at least one metal patch of the plurality of metal patches;

wherein the laser layer is between the plurality of transmit/receive modules and the pixelated surface.

22. The method of claim 15 wherein the phase change material comprises:

germanium-telluride (GeTe) doped chalcogenide glass.

23. The method of claim 15 wherein the ground plane comprises:

a multiple-layer frequency selective reflector.

24. The method of claim 15 wherein the phase change material has an aspect ratio such that a width of the phase change material across the gap is substantially less than a length of the phase change material along the gap.

25. The method of claim 15 further comprising:

providing a control and driver circuit for controlling and selectively driving lasers of the plurality of lasers.

26. The method of claim 15 wherein the pixelated surface further comprises:

reconfigurable non-driven elements.

27. The method of claim 15 wherein:

the metallic patches have dimensions smaller than a wavelength for a desired radio frequency of operation.

28. The method of claim 15 further comprising:

reconfiguring the pixelated surface by setting a first plurality of the switches to a non-conducting state, and setting a second plurality of the switches to a conducting state;

where a non-conductive state is a state of substantially higher impedance than a conductive state.

29. The reconfigurable electro-magnetic tile of claim 15 wherein a diameter of each pin hole is less than a wavelength for a desired radio frequency of operation.