Surface scattering antenna improvements

• US 10,090,599 B2
• Filed: 06/03/2016
• Issued: 10/02/2018
• Est. Priority Date: 03/15/2013
• 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, Dallas, Jeff, Hannigan, Russell J., Kundtz, Nathan, Nash, David R., Stevenson, Ryan Allan
• Primary Examiner(s): Karacsony, Robert
• Application Number:
  US15/172,475
• Publication Number:
  US 20160359234A1
• Time in Patent Office: 851 Days
• CPC Class Codes: H01Q 13/22 Longitudinal slot in boundary wall of waveguide or transmission line H01Q13/203 takes precedence
• 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 3/22 varying the orientation in accordance with variation of frequency of radiated wave
• CPC Class Codes: H01Q 3/443 varying the phase velocity along a leaky transmission line frequency scanning H01Q3/22; non-resonant leaky-waveguide or transmission-line aerials H01Q13/20

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 patch 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. An antenna, comprising:

a waveguide; and

a plurality of subwavelength elements distributed along the waveguide with inter-element spacings less than one-third of a free-space wavelength corresponding to an operating frequency of the antenna, where the plurality of subwavelength elements have a plurality of adjustable individual electromagnetic responses to a guided wave mode of the waveguide, and the plurality of adjustable individual electromagnetic responses provide an adjustable radiation field of the antenna;

wherein the waveguide includes a conducting surface, and the plurality of subwavelength elements corresponds to a plurality of conducting patches respectively positioned at least partially above a respective plurality of irises in the conducting surface; and

wherein the plurality of conducting patches is configured to provide a plurality of individual radiation fields responsive to iris-intermediated couplings between the conducting patches and the guided wave mode.

2. The antenna of claim 1, wherein the operating frequency is a microwave frequency.

3. The antenna of claim 2, wherein the microwave frequency is a Ka or Ku band frequency.

4. The antenna of claim 2, wherein the microwave frequency is a Ku band frequency.

5. The antenna of claim 2, wherein the microwave frequency is a Q band frequency.

6. The antenna of claim 1, wherein the waveguide is a two-dimensional waveguide.

7. The antenna of claim 6, wherein the two-dimensional waveguide is a parallel plate waveguide and the conducting surface is an upper conductor of the parallel plate waveguide.

8. The antenna of claim 1, wherein the waveguide is a one-dimensional waveguide.

9. The antenna of claim 8, wherein the waveguide includes a closed waveguide and the conducting surface is an upper conductor of the closed waveguide.

10. The antenna of claim 1, wherein the waveguide includes a plurality of one-dimensional waveguides composing a two-dimensional antenna aperture.

11. The antenna of claim 10, wherein the plurality of one-dimensional waveguides is a plurality of closed waveguides and the conducting surface is one of a plurality of conducting surfaces that are respective upper conductors of closed waveguides.

12. The antenna of claim 1, wherein the irises are rectangular irises.

13. The antenna of claim 1, wherein the irises are slit-like irises.

14. The antenna of claim 1, wherein the conducting patches are rectangular patches.

15. The antenna of claim 1, further comprising:

a plurality of bias voltage lines configured to provide respective bias voltages between the plurality of conducting patches and the conducting surface.

16. An antenna, comprising:

a waveguide; and

a plurality of subwavelength elements distributed along the waveguide with inter-element spacings less than one-third of a free-space wavelength corresponding to an operating frequency of the antenna, where the plurality of subwavelength elements are a plurality of subwavelength patch elements having a plurality of adjustable individual electromagnetic responses to a guided wave mode of the waveguide, and the plurality of adjustable individual electromagnetic responses provide an adjustable radiation field of the antenna;

where the plurality of subwavelength elements includes first and second subsets of subwavelength elements having radiation patterns that are substantially orthogonal.

17. The antenna of claim 16, wherein the first and second subsets of subwavelength elements have radiation patterns that are substantially linearly polarized and substantially orthogonal.

18. The antenna of claim 16, wherein the first and second subsets of subwavelength elements are first and second subsets of subwavelength elements that are perpendicularly oriented.

19. The antenna of claim 18, wherein the first and second subsets of subwavelength elements are perpendicularly oriented on a surface on the waveguide.

20. The antenna of claim 16, wherein the first and second subsets of subwavelength elements are adjusted so that the adjustable radiation field of the antenna is a linearly-polarized radiation field.

21. The antenna of claim 16, wherein the first and second subsets of subwavelength elements are adjusted so that the adjustable radiation field of the antenna is a circularly-polarized radiation field.

22. The antenna of claim 16, wherein the first and second subsets of subwavelength elements are adjusted so that the adjustable radiation field of the antenna is an elliptically-polarized radiation field.

23. The antenna of claim 16, wherein the first subset of subwavelength elements is a subset of subwavelength elements oriented at about +45°

with respect to a propagation direction of the waveguide, and the second subset of subwavelength elements is a subset of subwavelength elements oriented at about −

45°

with respect to the propagation direction of the waveguide.

24. An antenna, comprising:

a waveguide; and

a plurality of subwavelength patch elements distributed along the waveguide with inter-element spacings less than one-third of a free-space wavelength corresponding to an operating frequency of the antenna, where the plurality of subwavelength patch elements have a plurality of adjustable individual electromagnetic responses to a guided wave mode of the waveguide, and the plurality of adjustable individual electromagnetic responses provide an adjustable radiation field of the antenna;

wherein the waveguide includes a conducting surface, and the plurality of subwavelength elements corresponds to a plurality of conducting patches respectively positioned at least partially above a respective plurality of irises in the conducting surface; and

wherein the antenna further comprises;

a plurality of biasing circuits configured to provide respective bias voltages between the plurality of conducting patches and the conducting surface;

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 24, wherein the subwavelength patch elements are arranged in rows and columns.

26. The antenna of claim 24, wherein each of the plurality of biasing circuits includes a switching device.

27. The antenna of claim 26, wherein the switching device is a transistor.

28. The antenna of claim 27, wherein the transistor is a thin-film transistor (TFT).

29. The antenna of claim 24, wherein the plurality of biasing circuits includes a plurality of circuits mounted on the waveguide with a surface mount technology (SMT).

30. The antenna of claim 24, wherein the biasing circuits configured to provide respective bias voltages are biasing circuits configured to provide respective AC bias voltages.

31. The antenna of claim 30, wherein the respective AC bias voltages have minimal or zero DC offset.

32. The antenna of claim 30, wherein the biasing circuits configured to provide AC bias voltages are biasing circuits configured to provide AC bias voltages with adjustable RMS voltage levels.

33. The antenna of claim 30, wherein the biasing circuits configured to provide AC bias voltages are biasing circuits configured to provide AC bias voltages with adjustable amplitudes.

34. The antenna of claim 30, wherein the biasing circuits configured to provide AC bias voltages are biasing circuits configured to provide AC bias voltages with adjustable pulse widths.