SURFACE SCATTERING ANTENNA IMPROVEMENTS

• US 20140266946A1
• Filed: 03/15/2013
• Published: 09/18/2014
• Est. Priority Date: 03/15/2013
• Status: Active Grant

• Current Assignee: The Invention Science Fund I, L.L.C. (Intellectual Ventures LLC)
• Original Assignee: Searete LLC (Intellectual Ventures LLC)
• Inventors: KUNDTZ, NATHAN, BILY, ADAM, DALLAS, JEFF, HANNIGAN, RUSSELL J., NASH, DAVID R., STEVENSON, RYAN ALLAN
• Granted Patent: US 9,385,435 B2
• Time in Patent Office: Days
• US Class Current: 343/771
• 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 wave-propagating structure; and

a plurality of subwavelength patch elements distributed along the wave-propagating structure with inter-element spacings substantially less than 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 wave-propagating structure, and the plurality of adjustable individual electromagnetic responses provide an adjustable radiation field of the antenna.

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

9. The antenna of claim 1, wherein the wave-propagating structure includes one or more conducting surfaces, and the plurality of subwavelength patch elements corresponds to a plurality of conducting patches positioned at least partially above a respective plurality of irises in the one or more conducting surfaces.

10. The antenna of claim 9, wherein the one or more conducting surfaces define first and second directions parallel to the one or more conducting surfaces, the first direction being perpendicular to the second direction.

11. The antenna of claim 10, wherein the wave-propagating structure is a substantially two-dimensional wave-propagating structure.

12. The antenna of claim 11, 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.

13. The antenna of claim 10, wherein the wave-propagating structure includes one or more substantially one-dimensional wave-propagating structures.

14. The antenna of claim 13, wherein the one or more substantially one-dimensional wave-propagating structures include one or more closed waveguides oriented along the first direction, and the one or more conducting surfaces are one or more respective upper surfaces of the one or more closed waveguides.

26. The antenna of claim 9, wherein the plurality of conducting patches is configured to provide a plurality of elliptically-polarized radiation fields responsive to iris-intermediated couplings between the conducting patches and the guided wave mode.

27. The antenna of claim 26, wherein the guided wave mode defines a plurality of time-dependent H-fields at respective locations of the plurality of irises, and the time-dependent H-fields are vectors sweeping out a plurality of ellipses.

28. The antenna of claim 27, wherein the ellipses are substantially circular.

3. (canceled)

4. (canceled)

5. (canceled)

6. (canceled)

7. (canceled)

8. (canceled)

15-25. -25. (canceled)

29-52. -52. (canceled)

53. A method, comprising:

propagating a first guided wave to deliver a first plurality of relative phases to a respective plurality of locations;

coupling to the first guided wave at a first set of locations selected from the respective plurality of locations to radiate a first plurality of elliptically-polarized waves from the first set of locations, the first plurality of elliptically-polarized waves producing a first radiation field;

propagating a second guided wave to deliver a second plurality of relative phases to the respective plurality of locations, where the second plurality of relative phases is substantially equal to the first plurality of relative phases; and

coupling to the second guided wave at a second set of locations selected from the respective plurality of locations to radiate a second plurality of elliptically-polarized waves from the second set of locations, the second plurality of elliptically-polarized waves producing a second radiation field different from the first radiation field.

54. The method of claim 53, wherein:

the first guided wave and the first radiation field define a first interference pattern, and the first set of locations selected from the respective plurality of locations corresponds to a set of locations within constructive interference regions of the first interference pattern; and

the second guided wave and the second radiation field define a second interference pattern different from the first interference pattern, and the second set of locations selected from the respective plurality of locations corresponds to a set of locations within constructive interference regions of the second interference pattern.

55. The method of claim 53, wherein the first plurality of elliptically-polarized waves is a first plurality of circularly-polarized waves.

56. The method of claim 53, wherein the first plurality of elliptically-polarized waves is a first plurality of left-hand elliptically polarized waves.

57. The method of claim 53, wherein the first plurality of elliptically-polarized waves is a first plurality of right-hand elliptically polarized waves.

58. The method of claim 57, further comprising:

propagating a third guided wave to deliver a third plurality of relative phases to the respective plurality of locations, a propagation direction of the third guided wave being opposite to a propagation direction of the first guided wave; and

coupling to the third guided wave at a third set of locations selected from the respective plurality of locations to radiate a plurality of left-hand elliptically-polarized waves from the third set of locations.

59. The method of claim 58, wherein the third set of locations is equal to the first set of locations.

60. A method, comprising:

receiving a first elliptically-polarized free-space wave at a plurality of locations;

coupling to the first elliptically-polarized free-space wave at a first set of locations selected from the plurality of locations to produce a first plurality of electromagnetic oscillations at the first set of locations, the first plurality of electromagnetic oscillations producing a first guided wave having a first plurality of relative phases at the plurality of locations;

receiving a second elliptically-polarized free-space wave different from the first elliptically-polarized free-space wave at the plurality of locations;

coupling to the second elliptically-polarized free-space wave at a second set of locations selected from the plurality of locations to produce a second plurality of electromagnetic oscillations at the second set of locations, the second plurality of electromagnetic oscillations producing a second guided wave having a second plurality of relative phases at the plurality of locations, where the second plurality of relative phases is substantially equal to the first plurality of relative phases.

61. The method of claim 60, wherein:

the first guided wave and the first elliptically-polarized free-space wave define a first interference pattern, and the first set of locations selected from the respective plurality of locations corresponds to a set of locations within constructive interference regions of the first interference pattern; and

the second guided wave and the second elliptically-polarized free-space wave define a second interference pattern different from the first interference pattern, and the second set of locations selected from the respective plurality of locations corresponds to a set of locations within constructive interference regions of the second interference pattern.

62. The method of claim 60, wherein the first elliptically-polarized free-space wave is a circularly-polarized free-space wave.

63. The method of claim 60, wherein the first elliptically-polarized free-space wave is a left-hand elliptically-polarized free-space wave.

64. The method of claim 60, wherein the first elliptically-polarized free-space wave is a right-hand elliptically-polarized free-space wave.

65. The method of claim 64, further comprising:

receiving a left-hand elliptically-polarized free-space wave at the plurality of locations;

coupling to the right-hand elliptically-polarized free-space wave at a third set of locations selected from the plurality of locations to produce a third plurality of electromagnetic oscillations at the third set of locations, the third plurality of electromagnetic oscillations producing a third guided wave, a propagation direction of the third guided wave being opposite to a propagation direction of the first guided wave.

66. The method of claim 65, wherein the third set of locations is equal to the first set of locations.

67-117. -117. (canceled)