Antenna system having at least two apertures facilitating reduction of interfering signals

• US 9,923,271 B2
• Filed: 10/21/2013
• Issued: 03/20/2018
• Est. Priority Date: 10/21/2013
• Status: Active Grant

• Current Assignee: Elwha LLC (Intellectual Ventures LLC)
• Original Assignee: Elwha LLC (Intellectual Ventures LLC)
• Inventors: Hyde, Roderick A., Kare, Jordin T., Wood, Jr., Lowell L.
• Primary Examiner(s): Smith, Graham
• Assistant Examiner(s): Bouizza, Michael
• Application Number:
  US14/059,188
• Publication Number:
  US 20150109178A1
• Time in Patent Office: 1,611 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 3/44 varying the electric or magnetic characteristics of reflecting, refracting, or diffracting devices associated with the radiating element

Abstract

Described embodiments include an antenna system and method. The antenna system includes at least two surface scattering antenna segments. Each segment includes a respective electromagnetic waveguide structure, and a respective plurality of electromagnetic wave scattering elements. The wave scattering elements are distributed along the waveguide structure, have an inter-element spacing substantially less than a free-space wavelength of a highest operating frequency of the antenna segment, have a respective activatable electromagnetic response to a propagating guided wave, and are operable in combination to produce a controllable radiation pattern. A gain definition circuit defines a series of at least two radiation patterns selected to facilitate a convergence on an antenna radiation pattern that maximizes a radiation performance metric. An antenna controller sequentially establishes each radiation pattern. A receiver receives the desired field of view signal and the undesired field of view signal.

Claims

1. An antenna system comprising:

an antenna assembly including at least two surface scattering antenna segments, each segment of the at least two surface scattering antenna segments including;

a respective electromagnetic waveguide structure; and

a respective plurality of electromagnetic wave scattering elements distributed along the waveguide structure and operable in combination to produce a controllable radiation pattern;

a gain definition circuit configured to define a series of at least two radiation patterns implementable by the at least two surface scattering antenna segments, the series of at least two respective radiation patterns selected to facilitate a convergence on an antenna radiation pattern that maximizes a radiation performance metric that includes reception of a signal from a desired field of view or rejection of a signal from an undesired field of view, wherein maximizing the radiation performance metric includes optimizing a combined signal strength received from the desired field of view and minimizing a combined signal strength from an undesired field of view, wherein the radiation performance metric includes a weighted combination of one or more antenna reception performance factors, subject to at least one constraint;

an antenna controller configured to sequentially establish each radiation pattern of the series of at least two radiation patterns by activating the respective electromagnetic response of selected electromagnetic wave scattering elements of the plurality of electromagnetic wave scattering elements of the at least two surface scattering antenna segments; and

a receiver configured to receive signals from the desired field of view and signals from the undesired field of view.

2. The antenna system of claim 1, wherein the respective plurality of electromagnetic wave scattering elements have an inter-element spacing substantially less than a free-space wavelength of a highest operating frequency of the antenna segment, and each electromagnetic wave scattering element of the plurality of electromagnetic wave scattering elements has a respective activatable electromagnetic response to a guided wave propagating in their respective waveguide structure.

3. The antenna system of claim 1, wherein the antenna assembly includes an at least substantially planar arrangement having the at least two antenna segments.

4. The antenna system of claim 1, wherein the antenna assembly includes a conformal arrangement of the at least two antenna segments.

5. The antenna system of claim 1, wherein the antenna assembly includes a first antenna segment optimized in area, orientation, or mounting to transmit or receive signals from a specific set or distribution of objects.

6. The antenna system of claim 1, wherein a first segment of the at least two segments includes a receiving aperture that is larger than a receiving aperture of a second segment of the at least two segments.

7. The antenna system of claim 1, wherein a receiving aperture of a first segment of the at least two segments and a receiving aperture of a second segment of the at least two segments are substantially equal.

8. The antenna system of claim 1, wherein the undesired field of view signal includes a possible interfering signal.

9. The antenna system of claim 1, wherein the desired field of view signal includes a possible target or desired signal.

10. The antenna system of claim 1, wherein the series of at least two radiation patterns is defined in advance.

11. The antenna system of claim 1, wherein the series of at least two radiation patterns is defined on the fly.

12. The antenna system of claim 1, wherein the series of the at least two radiation patterns is selected randomly from radiation patterns implementable by the at least two antenna segments.

13. The antenna system of claim 1, wherein the series of at least two radiation patterns are estimated or projected to facilitate the convergence.

14. The antenna system of claim 1, wherein the radiation performance metric includes maximizing a combined signal strength received from a desired field of view and minimizing a combined signal strength received from an undesired field of view.

15. The antenna system of claim 1, wherein an antenna reception radiation performance factor includes an amplitude of the signal received from the desired field of view, or an amplitude of the signal received from the undesired field of view.

16. The antenna system of claim 1, wherein an antenna reception radiation performance factor includes antenna gain for one or more desired directions or angular regions, or antenna gain for one or more undesired directions or angular regions.

17. The antenna system of claim 1, wherein the constraint of the antenna radiation performance metric includes a constraint on amplitude of the signal received from the desired field of view, or on an amplitude of the signal received from the undesired field of view.

18. The antenna system of claim 1, wherein the constraint of the antenna radiation performance metric includes a constraint on signal to noise ratio, signal to interference ratio, signal to clutter ratio, channel capacity, data rate, or error rate.

19. The antenna system of claim 1, wherein the optimized combined signal strength received from a desired field of view includes a maximum combined signal strength received from a desired field of view.

20. The antenna system of claim 1, wherein the gain definition circuit includes an adaptive gain definition circuit configured to define a second radiation pattern of the at least two radiation patterns responsive to a combined signal received from a desired field of view and a combined signal received from a undesired field of view with the at least two antenna segments configured in a first radiation pattern of the at least two radiation patterns.

21. The antenna system of claim 20, wherein the adaptive gain definition circuit is configured to define the a second radiation pattern of the series of at least two radiation patterns by modifying a previously implemented first radiation pattern of the series of at least two radiation patterns.

22. The antenna system of claim 20, wherein the adaptive gain definition circuit is configured to define the series of at least two radiation patterns in response to a selection algorithm.

23. The antenna system of claim 20, wherein the adaptive gain definition circuit is configured to define a second radiation pattern of the series of at least two radiation patterns in response to an amplitude or phase of a received desired field of view signal with the antenna segments configured in a first radiation pattern of the series of at least two radiation patterns.

24. The antenna system of claim 20, wherein the adaptive gain definition circuit is configured to define a second radiation pattern of the series of at least two radiation patterns in response to an amplitude or phase of a received undesired field of view signal with the antenna segments configured in a first radiation pattern of the series of at least two radiation patterns.

25. The antenna system of claim 20, wherein the adaptive gain definition circuit is configured to define the series of at least two respective radiation patterns in response to a library of at least three potential radiation patterns.

26. The antenna system of claim 20, wherein the adaptive gain definition circuit is configured to make at least two successive iterations of defining the set of at least two respective radiation patterns during a course of facilitating a convergence on an optimized combined signal strength received from the desired field of view and a minimized combined signal strength received from the undesired field of view.

27. The antenna system of claim 20, wherein the adaptive gain definition circuit is configured to define a second radiation pattern of the series of at least two radiation patterns in response to an amplitude or phase of a received desired field of view signal, and an amplitude or phase of a received undesired field of view signal, both received with the antenna segments configured in a first radiation pattern of the series of at least two radiation patterns.

28. The antenna system of claim 1, wherein the series of at least two radiation patterns are defined to adjust an amplitude or phase of the undesired field of view signal received by a first antenna segment relative to an amplitude or phase of the undesired field of view signal received by a second antenna segment of the at least two segments of the antenna assembly in a manner predicted to minimize the combined signal received from the undesired field of view by the first segment and the second segment.

29. The antenna system of claim 1, wherein the series of at least two radiation patterns are defined to:

a. adjust an amplitude or phase of the undesired field of view signal received by the first antenna segment relative to an amplitude or phase of the undesired field of view signal received by the second antenna segment of the of the at least two segments of the antenna assembly in a manner predicted to increase a degradation in the combined signals received from the undesired field of view by the first segment and the second segment; and

b. adjust an amplitude or phase of the desired field of view signal received by a first antenna segment relative to an amplitude or phase of the desired field of view signal received by a second antenna segment of the of the at least two segments of the antenna assembly in a manner predicted to minimize any degradation in the combined signals received from the desired field of view by the first segment and the second segment.

30. The antenna system of claim 1, wherein the series of at least two radiation patterns are defined to respectively adjust an amplitude or phase the desired field of view and of the undesired field of view signals received by the at least two segments of the antenna assembly in a manner predicted to minimize the combined signal received from the undesired field of view while substantially maintaining the combined signal received from the desired field of view.

31. The antenna system of claim 1, wherein the antenna assembly includes at least one respective electromagnetic waveguide structure for each segment of the at least two segments.

32. The antenna system of claim 31, wherein the electromagnetic waveguide structure is configured to generate at least one beam.

33. The antenna system of claim 1, further comprising:

a signal processing circuit configured to combine signals received from the at least two antenna segments and provide a cancellation of the signal from the undesired field of view.

34. The antenna system of claim 1, wherein the receiver includes a space-based satellite navigation system receiver.

35. The antenna system of claim 1, wherein the antenna assembly includes a first substantially planar antenna segment physically joined with a second substantially planar antenna segment.

36. The antenna system of claim 1, wherein the antenna assembly includes a first substantially planar antenna segment physically abutting or contiguous with a second substantially planar antenna segment.

37. The antenna system of claim 1, wherein the series of at least two radiation patterns is incrementally defined based on trial and error.

38. The antenna system of claim 1, wherein the series of the at least two radiation patterns is selected from a library of potential radiation patterns.

39. The antenna system of claim 1, wherein an antenna reception radiation performance factor includes signal to noise ratio, signal to interference ratio, signal to clutter ratio, channel capacity, data rate, or error rate.

40. The antenna system of claim 1, wherein the constraint of the antenna radiation performance metric includes a constraint on antenna gain for one or more desired directions or angular regions, or antenna gain for one or more undesired directions or angular regions.

41. The antenna system of claim 1, wherein the optimized combined signal strength received from a desired field of view includes a combined desired field of view signal optimized for processing by the receiver circuit.

42. The antenna system of claim 1, wherein the at least two surface scattering antenna segments may be physically contiguous or non-contiguous.