Antenna system with active spatial filtering surface

• US 20040008149A1
• Filed: 07/11/2002
• Published: 01/15/2004
• Est. Priority Date: 07/11/2002
• Status: Active Grant

• Current Assignee: Harris Corporation (L3Harris Technologies, Inc.)
• Original Assignee: Harris Corporation (L3Harris Technologies, Inc.)
• Inventors: Delgado, Heriberto, Killen, William D.
• Granted Patent: US 6,806,843 B2
• Time in Patent Office: Days
• US Class Current: 343/795
• CPC Class Codes: H01Q 15/0053 Selective devices used as spatial filter or angular sidelobe filter
• CPC Class Codes: H01Q 21/061 Two dimensional planar arrays
• CPC Class Codes: H01Q 3/46 Active lenses or reflecting arrays

Abstract

A spatial filtering surface includes a dielectric substrate and a plurality of spaced, resonant dipole elements positioned on the dielectric substrate. Each dipole element has dipole ends and an associated diode for controlling amplitude taper and a reflection phase of an electromagnetic field at a selected frequency with respect to an angle of incidence to the dielectric substrate. Bias lines interconnect the dipole elements for conducting a bias current to a dipole element.

Claims

1. An antenna system comprising:

a ground plane;

a plurality of antenna elements forming an antenna array; and

a spatial filtering surface positioned adjacent the antenna array through which electromagnetic radiation to or from the antenna array passes, said spatial filtering surface comprising a dielectric substrate and a plurality of spaced, resonant dipole elements positioned on the dielectric substrate, each dipole element having dipole ends and an associated diode for controlling any amplitude taper and reflection phase relative to the ground plane and antenna elements of electromagnetic radiation at a selected frequency with respect to an angle of incidence to the dielectric substrate.

2. A spatial filtering surface according to claim 1, wherein said dipole elements are arranged in a plurality of rows and equally spaced from each other within each row.

3. A spatial filtering surface according to claim 1, wherein an associated diode comprises a varactor diode having a capacitance for any associated dipole element.

4. A spatial filtering surface according to claim 1, and further comprising bias lines interconnecting said dipole elements for conducting a bias current to a dipole element and any associated diode.

5. A spatial filtering surface according to claim 4, wherein said bias lines are formed of metal to aid in controlling voltage of any associated diode.

6. A spatial filtering surface according to claim 4, wherein said bias lines are optical control lines.

7. A spatial filtering surface according to claim 1, wherein said antenna elements form a planar array, and said spatial filtering surface is substantially parallel to said planar array.

8. A spatial filtering surface according to claim 1, and further comprising a dielectric filler positioned between each dipole element positioned on the dielectric substrate.

9. An antenna system according to claim 1, and further comprising a metallic layer disposed on the dielectric layer, and wherein said resonant dipole elements are formed as geometric configured slots within the metallic layer.

10. An antenna system according to claim 1, wherein said dielectric layer comprises a plurality of dielectric layers.

11. An antenna system according to claim 1, and further comprising a dielectric layer overlying said resonant dipole elements.

12. An antenna system according to claim 11, wherein said dielectric layer overlying said resonant elements comprises a plurality of dielectric layers.

13. An antenna system according to claim 1, wherein said spatial filtering surface is formed as a multilayer spatial filtering surface comprising a plurality of spaced dielectric substrates each forming a spatial filtering surface layer having the resonant dipole elements positioned thereon.

20. A spatial filtering surface according to claim 1, wherein each spatial filtering surface layer is planar configured.

14. A multilayer spatial filtering surface used with an antenna system comprising:

a plurality of spaced dielectric substrates each forming a spatial filtering surface layer, each spatial filtering surface layer comprising;

a dielectric substrate;

a plurality of spaced, resonant dipole elements positioned on the dielectric substrate, each dipole element having dipole ends and an associated diode for controlling amplitude taper and a reflection phase of electromagnetic radiation at a selected frequency with respect to an angle of incidence to the dielectric substrate.

15. A spatial filtering surface according to claim 14, wherein said dipole elements are arranged in a plurality of rows and equally spaced from each other within each row.

16. A spatial filtering surface according to claim 14, wherein an associated diode comprises a varactor diode having a capacitance for the dipole elements.

17. A spatial filtering surface according to claim 16, and further comprising bias lines interconnecting said dipole elements for conducting a bias current to a dipole element and associated diode.

18. A spatial filtering surface according to claim 17, wherein said bias lines are formed of metal to aid in controlling voltage of an associated diode.

19. A spatial filtering surface according to claim 17, wherein said bias lines are optical control lines.

21. A spatial filtering surface according to claim 14, and further comprising a dielectric filler positioned between, above and below each resonant element positioned on a dielectric substrate, wherein a spatial filter taper transform is imparted when electromagnetic radiation passes therethrough.

22. A multilayer spatial filtering surface according to claim 14, wherein an air gap is formed between said spatial filtering surface layers.

23. A multilayer spatial filtering surface according to claim 14, and further comprising a dielectric layer positioned between spatial filtering surface layers.

24. A multilayer spatial filtering surface according to claim 14, wherein the distance between spatial filtering surface layers, the dielectric constant of dielectric substrates, and permeability of dielectric substrates are chosen to aid in imparting a desired spatial filter surface taper transform.

25. A multilayer spatial filtering surface according to claim 14, and further comprising a metallic layer disposed on the dielectric layer, and wherein said resonant dipole elements are formed as geometric configured slots within the metallic layer.

26. A multilayer spatial filtering surface according to claim 14, wherein said dielectric layer comprises a plurality of dielectric layers.

27. A multilayer spatial filtering surface according to claim 14, and further comprising a dielectric layer overlying said resonant dipole elements.

28. A multilayer spatial filtering surface according to claim 27, wherein said dielectric layer overlying said resonant dipole elements comprises a plurality of dielectric layers.

29. A spatial filtering surface used with an antenna system comprising:

a dielectric substrate;

a plurality of spaced, resonant dipole elements positioned on the dielectric substrate, each dipole element having dipole ends and an associated diode for controlling amplitude taper and a reflection phase of an electromagnetic field at a selected frequency with respect to an angle of incidence to the dielectric substrate.

30. A spatial filtering surface according to claim 29, wherein said dipole elements are arranged in a plurality of rows and equally spaced from each other within each row.

31. A spatial filtering surface according to claim 29, wherein an associated diode comprises varactor diodes having a capacitance for the dipole elements.

32. A spatial filtering surface according to claim 29, and further comprising bias lines interconnecting said dipole elements for conducting a bias current to a dipole element.

33. A spatial filtering surface according to claim 32, wherein said bias lines are formed of metal to aid in controlling voltage of said diodes.

34. A spatial filtering surface according to claim 32, wherein said bias lines are optical control lines.

35. A spatial filtering surface according to claim 29, and further comprising a dielectric filler positioned between, above and below each resonant element positioned on the dielectric substrate, wherein a spatial filter taper transform is imparted when electromagnetic radiation passes therethrough.

36. A spatial filtering surface according to claim 29, wherein said dipole elements are printed on said dielectric substrate.