Antenna system with spatial filtering surface

• US 6,900,763 B2
• Filed: 07/11/2002
• Issued: 05/31/2005
• Est. Priority Date: 07/11/2002
• Status: Active Grant

• Current Assignee: North South Holdings Incorporated (Spherix Incorporated)
• Original Assignee: Harris Corporation (L3Harris Technologies, Inc.)
• Inventors: Killen, William D., Delgado, Heriberto
• Primary Examiner(s): Ho, Tan
• Application Number:
  US10/193,338
• Publication Number:
  US 20040008147A1
• Time in Patent Office: 1,055 Days
• Field of Search: 343/700.MS, 343/756, 343/909, 343/853, 333/134, 333/202
• US Class Current: 343/700.0MS
• CPC Class Codes: H01Q 15/0053 Selective devices used as spatial filter or angular sidelobe filter

Abstract

An antenna system includes a ground plane and/or antenna elements forming an antenna array. A spatial filtering surface is positioned adjacent the antenna array through which electromagnetic radiation to or from the antenna array passes. The spatial filtering surface includes a dielectric substrate and a plurality of spaced, geometric configured, resonant elements printed on the dielectric substrate and configured and spaced from each other to have a resonant frequency to filter an electromagnetic field at a selected frequency with respect to an angle of incidence to the dielectric substrate. A dielectric filler is positioned between, above and below each resonant element printed on the dielectric substrate. A spatial filter taper transform is imparted when electromagnetic radiation passes therethrough. A standing wave is created between the ground plane and spatial filtering surface.

Claims

1. An antenna system comprising:

a ground plane;

a plurality of antenna elements forming an antenna array; and

a substantially planar 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 substantially planar dielectric substrate, a plurality of spaced, geometric configured, resonant elements printed on the dielectric substrate and configured and spaced from each other to have a resonant frequency to filter an electromagnetic field at a selected frequency with respect to an angle of incidence to the dielectric substrate, and a dielectric filler positioned between, above and below each resonant element printed on the dielectric substrate and forming a substantially planar spatial filtering surface, wherein a spatial filter taper transform is imparted when electromagnetic radiation passes therethrough and a standing wave is created between the ground plane and/or antenna and spatial filtering surface.

2. An antenna system according to claim 1, wherein said resonant elements are formed by a plurality of wire elements printed on the dielectric substrate.

3. An antenna system according to claim 2, wherein said wire elements are configured as hexagons.

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

5. An antenna system according to claim 4, wherein said geometric configured slots are formed as hexagons.

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

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

8. An antenna system according to claim 7, wherein said dielectric layer overlying said resonant elements comprises a plurality of dielectric layers.

9. An antenna system according to claim 1, wherein said filler comprises an adhesive film.

10. An antenna system according to claim 1, wherein said filler is formed from an air gap between, above and below resonant elements.

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

12. An antenna system according to claim 11, wherein an air gap is formed between said spatial filtering surface layers.

13. An antenna system according to claim 11, and further comprising a dielectric layer positioned between said spatial filtering surface layers.

14. An antenna system according to claim 11, wherein the distance between spatial filtering surface layers, the dielectric constant of dielectric substrates and permeability of dielectric substrates are chosen to impart a desired spatial filter surface taper transform.

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

a substantially planar dielectric substrate forming a spatial filtering surface layer and having a plurality of spaced, geometric configured, resonant elements printed on the substantially planar dielectric substrate and configured and spaced from each other to have a resonant frequency to filter an electromagnetic field at a selected frequency with respect to an angle of incidence to the dielectric substrate, and a dielectric filler positioned between, above and below each resonant element printed on the dielectric substrate to form a substantially planar spatial filtering surface, wherein a spatial filter surface taper transform is imparted thereto when electromagnetic radiation passes therethrough.

16. A multilayer spatial filtering surface according to claim 15, wherein an air gap is formed between said spatial filtering surface layers.

17. A multilayer spatial filtering surface according to claim 15, and further comprising a dielectric layer positioned between said spatial filtering surface layers.

18. A multilayer spatial filtering surface according to claim 15, 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.

19. A multilayer spatial filtering surface according to claim 15, wherein said resonant elements are formed by a plurality of wire elements printed on the dielectric substrate.

20. A multilayer spatial filtering surface according to claim 19, wherein said wire elements are configured as hexagons.

21. A multilayer spatial filtering surface according to claim 15, and further comprising a metallic layer disposed on the dielectric layer, and wherein said resonant elements are formed as geometric configured slots within the metallic layer.

22. A multilayer spatial filtering surface according to claim 21, wherein said geometric configured slots are formed as hexagons.

23. A multilayer spatial filtering surface according to claim 15, wherein said dielectric substrate comprises a plurality of dielectric layers.

24. A multilayer spatial filtering surface according to claim 15, and further comprising a dielectric layer overlying said resonant elements.

25. A multilayer spatial filtering surface according to claim 24, wherein said dielectric layer overlying said resonant elements comprises a plurality of dielectric layers.

26. A multilayer spatial filtering surface according to claim 15, wherein said filler comprises an adhesive film.

27. A multilayer spatial filtering surface according to claim 15, wherein said filler is formed from an air gap between, above and below resonant elements.

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

a substantially planar dielectric substrate;

a plurality of spaced, geometric configured, resonant elements printed on the dielectric substrate and configured and spaced from each other to have a resonant frequency to filter an electromagnetic field at a selected frequency with respect to an angle of incidence to the dielectric substrate; and

a dielectric filler positioned between each resonant element printed on dielectric substrate and forming a substantially planar spatial filtering surface, wherein a spatial filter taper transform is imparted when electromagnetic radiation passes therethrough.

29. A spatial filtering surface according to claim 28, wherein said resonant elements are formed by a plurality of wire elements printed on the dielectric substrate.

30. A spatial filtering surface according to claim 29, wherein said wire elements are configured as hexagons.

31. A spatial filtering surface according to claim 28, and further comprising a metallic layer disposed on the dielectric layer, and wherein said resonant elements are formed as geometric configured slots within the metallic layer.

32. A spatial filtering surface according to claim 31, wherein said geometric configured slots are formed as hexagons.

33. A spatial filtering surface according to claim 28, wherein said dielectric substrate comprises a plurality of dielectric layers.

34. A spatial filtering surface according to claim 28, and further comprising a dielectric layer overlying said resonant elements.

35. A spatial filtering surface according to claim 34, wherein said dielectric layer overlying said resonant elements comprises a plurality of dielectric layers.

36. A spatial filtering surface according to claim 28, wherein said filler comprises an adhesive film.

37. A spatial filtering surface according to claim 28, wherein said filler is formed from an air gap between resonant elements.