Surface scattering antennas

• US 10,062,968 B2
• Filed: 05/25/2016
• Issued: 08/28/2018
• Est. Priority Date: 10/15/2010
• Status: Active Grant

• Current Assignee: The Invention Science Fund I, L.L.C. (Intellectual Ventures LLC)
• Original Assignee: The Invention Science Fund I, L.L.C. (Intellectual Ventures LLC)
• Inventors: Bily, Adam, Boardman, Anna K., Hannigan, Russell J., Hunt, John Desmond, Kundtz, Nathan, Nash, David R., Stevenson, Ryan Allan, Sullivan, Philip A.
• Primary Examiner(s): Baltzell, Andrea Lindgren
• Application Number:
  US15/164,211
• Publication Number:
  US 20160372834A1
• Time in Patent Office: 825 Days
• CPC Class Codes: H01Q 13/28 comprising elements constituting electric discontinuities and spaced in direction of wave propagation, e.g. dielectric elements or conductive elements forming artificial dielectric
• CPC Class Codes: H01Q 15/0006 Devices acting selectively as reflecting surface, as diffracting or as refracting device, e.g. frequency filtering or angular spatial filtering devices H01Q15/12, H01Q15/22, H01Q15/24 take precedence
• CPC Class Codes: H01Q 15/0066 said selective devices being reconfigurable, tunable or controllable, e.g. using switches
• CPC Class Codes: H01Q 15/0086 said selective devices having materials with a synthesized negative refractive index, e.g. metamaterials or left-handed materials
• CPC Class Codes: H01Q 15/02 Refracting or diffracting devices, e.g. lens, prism
• CPC Class Codes: H01Q 15/10 comprising three-dimensional array of impedance discontinuities, e.g. holes in conductive surfaces or conductive discs forming artificial dielectric
• CPC Class Codes: H01Q 3/00 Arrangements for changing or varying the orientation or the shape of the directional pattern of the waves radiated from an antenna or antenna system means for positioning H01Q1/125

Abstract

Surface scattering antennas provide adjustable radiation fields by adjustably coupling scattering elements along a wave-propagating structure. In some approaches, the scattering elements are complementary metamaterial elements. In some approaches, the scattering elements are made adjustable by disposing an electrically adjustable material, such as a liquid crystal, in proximity to the scattering elements. Methods and systems provide control and adjustment of surface scattering antennas for various applications.

Claims

1. A system, comprising:

a surface scattering antenna that is adjustable responsive to one or more external inputs;

antenna control circuitry configured to provide the one or more external inputs; and

communications circuitry coupled to a feed structure of the surface scattering antenna;

where the surface scattering antenna includes;

at least one feed connector for launching a guided wave when receiving an electromagnetic signal via the feed structure;

a waveguide arranged for propagating said guided wave; and

a plurality of scattering elements distributed along the waveguide with inter-element spacings substantially less than a free-space wavelength corresponding to an operating frequency of the antenna,

where the plurality of scattering elements have;

electromagnetic properties that are adjustable in response to the one or more external inputs;

a plurality of adjustable individual electromagnetic responses to said guided wave mode in the waveguide, and

said adjustable electromagnetic properties and said plurality of adjustable individual electromagnetic responses provide an adjustable radiation field of the antenna when said guided wave is scattered at said plurality of scattering elements;

wherein the one or more external inputs include a plurality of respective bias voltages for the plurality of scattering elements.

2. A system, comprising:

a surface scattering antenna that is adjustable responsive to one or more external inputs;

antenna control circuitry configured to provide the one or more external inputs; and

communications circuitry coupled to a feed structure of the surface scattering antenna;

where the surface scattering antenna includes;

at least one feed connector for launching a guided wave when receiving an electromagnetic signal via the feed structure;

a waveguide arranged for propagating said guided wave; and

a plurality of scattering elements distributed along the waveguide with inter-element spacings substantially less than a free-space wavelength corresponding to an operating frequency of the antenna,

where the plurality of scattering elements have;

electromagnetic properties that are adjustable in response to the one or more external inputs;

a plurality of adjustable individual electromagnetic responses to said guided wave mode in the waveguide, and

said adjustable electromagnetic properties and said plurality of adjustable individual electromagnetic responses provide an adjustable radiation field of the antenna when said guided wave is scattered at said plurality of scattering elements;

wherein the antenna control circuitry includes;

a storage medium that includes a lookup table mapping a set of antenna radiation pattern parameters to a corresponding set of values for the one or more control inputs.

3. The system of claim 2, wherein the set of antenna radiation pattern parameters includes a set of antenna beam directions.

4. The system of claim 2, wherein the set of antenna radiation pattern parameters includes a set of antenna null directions.

5. The system of claim 2, wherein the set of antenna radiation pattern parameters includes a set of antenna beam widths.

6. The system of claim 2, wherein the set of antenna radiation pattern parameters includes a set of polarization states.

7. A system, comprising:

a surface scattering antenna that is adjustable responsive to one or more external inputs;

antenna control circuitry configured to provide the one or more external inputs; and

communications circuitry coupled to a feed structure of the surface scattering antenna;

where the surface scattering antenna includes;

at least one feed connector for launching a guided wave when receiving an electromagnetic signal via the feed structure;

a waveguide arranged for propagating said guided wave; and

a plurality of scattering elements distributed along the waveguide with inter-element spacings substantially less than a free-space wavelength corresponding to an operating frequency of the antenna,

where the plurality of scattering elements have;

electromagnetic properties that are adjustable in response to the one or more external inputs;

a plurality of adjustable individual electromagnetic responses to said guided wave mode in the waveguide, and

said adjustable electromagnetic properties and said plurality of adjustable individual electromagnetic responses provide an adjustable radiation field of the antenna when said guided wave is scattered at said plurality of scattering elements;

wherein the antenna control circuitry includes;

processor circuitry configured to calculate a set of values for the one or more external inputs corresponding to a desired antenna radiation pattern parameter.

8. The system of claim 7, wherein the processor circuitry is configured to calculate the set of values for the for the one or more external inputs by computing a holographic pattern corresponding to the desired antenna radiation pattern parameter.

9. A system, comprising:

a surface scattering antenna that is adjustable responsive to one or more external inputs;

antenna control circuitry configured to provide the one or more external inputs; and

communications circuitry coupled to a feed structure of the surface scattering antenna;

where the surface scattering antenna includes;

at least one feed connector for launching a guided wave when receiving an electromagnetic signal via the feed structure;

a waveguide arranged for propagating said guided wave; and

a plurality of scattering elements distributed along the waveguide with inter-element spacings substantially less than a free-space wavelength corresponding to an operating frequency of the antenna,

where the plurality of scattering elements have;

electromagnetic properties that are adjustable in response to the one or more external inputs;

a plurality of adjustable individual electromagnetic responses to said guided wave mode in the waveguide, and

said adjustable electromagnetic properties and said plurality of adjustable individual electromagnetic responses provide an adjustable radiation field of the antenna when said guided wave is scattered at said plurality of scattering elements;

and further comprising;

a sensor unit configured to detect an environmental condition of the surface scattering antenna.

10. The system of claim 9, wherein the sensor unit includes one or more sensors selected from GPS sensors, thermometers, gyroscopes, accelerometers, and strain gauges.

11. The system of claim 9, wherein the environmental condition includes a position, an orientation, a temperature, or a mechanical deformation of the surface scattering antenna.

12. The system of claim 9, wherein the sensor unit is configured to provide environmental condition data to the antenna control circuitry, and the antenna control circuitry includes:

circuitry configured to adjust the one or more external inputs to compensate for changes in the environmental condition of the surface scattering antenna.

13. A surface scattering antenna, comprising:

at least one feed connector for launching a guided wave when receiving an electromagnetic signal via a feed structure;

a waveguide arranged for propagating said guided wave; and

a plurality of scattering elements distributed along the waveguide with inter-element spacings substantially less than a free-space wavelength corresponding to an operating frequency of the antenna,

where the plurality of scattering elements have;

electromagnetic properties that are adjustable in response to one or more external inputs;

a plurality of adjustable individual electromagnetic responses to said guided wave mode in the waveguide, and

said adjustable electromagnetic properties and said plurality of adjustable individual electromagnetic responses provide an adjustable radiation field of the antenna when said guided wave is scattered at said plurality of scattering elements.

14. The antenna of claim 13,

wherein the waveguide includes one or more conducting surfaces and the plurality of scattering elements corresponds to a plurality of apertures within the one or more conducting surfaces;

and

wherein the plurality of apertures defines a respective plurality of conducting islands that are electrically disconnected from the one or more conducting surfaces, and the antenna further comprises;

a plurality of bias voltage lines or biasing circuits configured to provide respective bias voltages between the one or more conducting surfaces and the respective plurality of conducting islands.

15. The antenna of claim 14, wherein the operating frequency is a microwave frequency.

16. The antenna of claim 14, wherein the wave-propagating structure is a substantially two-dimensional wave-propagating structure.

17. The antenna of claim 16, wherein the substantially two-dimensional wave-propagating structure is a parallel plate waveguide, and the one or more conducting surfaces are an upper conductor of the parallel plate waveguide.

18. The antenna of claim 14, wherein the wave-propagating structure includes one or more substantially one-dimensional wave-propagating structures.

19. The antenna of claim 18, wherein the one or more substantially one-dimensional wave-propagating structures are a plurality of substantially one-dimensional wave-propagating structures composing a substantially two-dimensional antenna area.

20. The antenna of claim 18, wherein the one or more substantially one-dimensional wave-propagating structures include one or more closed waveguides.

21. The antenna of claim 20, wherein the one or more closed waveguides include one or more rectangular waveguides.

22. The antenna of claim 20, wherein the one or more conducting surfaces are one or more respective upper surfaces of the one or more closed waveguides.

23. The antenna of claim 20, wherein the one or more conducting surfaces are positioned above one or more respective upper surfaces of the one or more closed waveguides, and the one or more respective upper surfaces include a plurality of irises adjacent to the plurality of apertures within the one or more conducting surfaces.

24. The antenna of claim 14, wherein the plurality of apertures are arranged in rows and columns, the plurality of bias voltage lines or biasing circuits is a plurality of biasing circuits, and the antenna further comprises:

a set of row control lines each addressing a row of the plurality of biasing circuits; and

a set of column control lines each addressing a column of the plurality of biasing circuits.

25. The antenna of claim 14, further comprising:

an electrically adjustable material disposed at least partially within respective vicinities of the plurality of apertures.

26. The antenna of claim 25, wherein the electrically adjustable material is a liquid crystal material.

27. The antenna of claim 14, wherein the scattering elements include active elements and the bias voltages are bias voltages for the active elements.

28. The antenna of claim 27, wherein the active elements are selected from varactors, transistors, or diodes.

29. The antenna of claim 13, wherein the one or more external inputs include a plurality of respective bias voltages for the plurality of scattering elements.

30. The antenna of claim 13, further comprising antenna control circuitry configured to provide the one or more external inputs, wherein the antenna control circuitry includes a storage medium that includes a lookup table mapping a set of antenna radiation pattern parameters to a corresponding set of values for the one or more control inputs.

31. The antenna of claim 30, wherein the set of antenna radiation pattern parameters includes a set of antenna beam directions, antenna null directions, antenna beam widths, or polarization states.

32. The antenna of claim 13, further comprising antenna control circuitry configured to provide the one or more external inputs, wherein the antenna control circuitry includes processor circuitry configured to calculate a set of values for the one or more external inputs corresponding to a desired antenna radiation pattern parameter.

33. The antenna of claim 13, further comprising a sensor unit configured to detect an environmental condition of the surface scattering antenna.

34. The antenna of claim 33, wherein the sensor unit includes one or more sensors selected from GPS sensors, thermometers, gyroscopes, accelerometers, and strain gauges.

35. The antenna of claim 33, wherein the environmental condition includes a position, an orientation, a temperature, or a mechanical deformation of the surface scattering antenna.

36. The antenna of claim 33, further comprising antenna control circuitry configured to provide the one or more external inputs, wherein the sensor unit is configured to provide environmental condition data to the antenna control circuitry, and the antenna control circuitry includes:

circuitry configured to adjust the one or more external inputs to compensate for changes in the environmental condition of the surface scattering antenna.