Reconfigurable fluidic shutter for selectively shielding an antenna array

1. A reconfigurable fluidic shutter for selectively shielding an antenna array comprising:

a first surface and a second surface spaced apart and defining a cavity therebetween; and

at least one pump configured to pump a liquid that attenuates electromagnetic radiation into the cavity, out of the cavity, or both;

wherein the first and second surfaces are transparent to electromagnetic radiation.

2. The shutter according to claim 1 , further comprising:

a storage container configured to store the liquid.

3. The shutter according to claim 1 , wherein the first and second surfaces are curved.

4. The shutter according to claim 1 , wherein the first and second surfaces are planar.

5. The shutter according to claim 1 , wherein the at least one pump comprises first and second pumps, the first pump configured to pump the liquid into the cavity, out of the cavity, or both; and

the second pump configured to pump a gas or liquefied dielectric composition into the cavity, out of the cavity, or both.

6. The shutter according to claim 5 , further comprising:

a second storage container configured to store the gas or liquefied dielectric composition.

7. The shutter according to claim 5 , further comprising:

a piston configured to be moved within the cavity; and

an actuator or motor configured to move the piston.

8. The shutter according to claim 7 , wherein the piston is configured to prevent the liquid and the liquefied dielectric from mixing or interacting.

9. The shutter according to claim 7 , further comprising:

at least one rail in the cavity upon which the piston slides along.

10. The shutter according to claim 1 , wherein the liquid comprises particles configured to affect the dielectric properties thereof and electromagnetic radiation propagation through the liquid.

11. The shutter according to claim 10 , wherein the liquid is selected from the group consisting of: low-melt waxes, olefins, and fluorocarbons.

12. The shutter according to claim 10 , wherein the particles are selected from the group consisting of: carbon nanotubes, and organic polymers.

13. The shutter according to claim 1 , wherein the liquid comprises a liquefied metal or alloy composition.

14. The shutter according to claim 13 , wherein the liquefied metal or alloy composition is selected from the group consisting of: Cs 77%, K 23.0%; Hg 100%; Ga 68.5%, In 21.5%, Sn 10%; K 78.0%, Na 22.0%; Ga 62.5%, In 21.5%, Sn 16.0%; Ga 69.8%, In 21.5%, Sn 12.5.0%; Ga 100%; Bi 40.63%, Pb 22.1%, In 18.1%, Sn 10.65%, Cd 8.2%; Bi 32.5%, In 51.0%, Sn 16.5%; Bi 50.0%, Pb 25.0%, Sn 12.50%, Cd 12.5%; Bi 50.0%, Pb 31.2%, Sn 18.80%; Bi 50.0%, Pb 28.0%, Sn 22.0%; Sn 63.0%, Pb 37.0%; and Sn 92.0%, Zn 8.0%.

15. The shutter according to claim 1 , wherein the cavity comprises a plurality of channels.

16. The shutter according to claim 15 , wherein the channels are spaced apart less than λ/8, where λ is a wavelength of a desired electromagnetic signal to be received and/or transmitted by the antenna array.

17. The shutter according to claim 15 , wherein the channels are oriented orthogonal to a polarization of a radiated field.

18. The shutter according to claim 1 , further comprising:

heating elements and/or insulation to maintain the liquid in a liquid state.

19. The shutter according to claim 1 , wherein the at least one pump is configured to inject the liquid into the cavity, to remove the liquid from the cavity, or both, at around the speed of sound in an uncompressible liquid.

20. An antenna comprising:

an antenna array; and

a shutter according to claim 1 arranged to selectively shield the antenna array.

21. A method of selectively shielding an antenna array comprising:

providing the shutter of claim 1 ; and

selectively pumping liquid that attenuates electromagnetic radiation into the shutter, out of the shutter, or both.