Reflector with attenuating connecting plates

• US 4,585,317 A
• Filed: 11/02/1982
• Issued: 04/29/1986
• Est. Priority Date: 11/05/1981
• Status: Expired due to Fees

• Current Assignee: Pico-Savac Incorporated
• Original Assignee: Marvin Hodges
• Inventors: Hodges, Marvin P., Hodges, Gilbert P.
• Primary Examiner(s): Corbin, John K.
• Assistant Examiner(s): Lewis, David
• Application Number:
  US06/438,489
• Time in Patent Office: 1,274 Days
• Field of Search: 350/292, 350/293, 350/299, 350/303, 126/417, 126/424, 126/438, 126/450, 343/840, 343/832-834, 362/341
• US Class Current: 359/852
• CPC Class Codes: F24S 2023/833 dish-shaped
• CPC Class Codes: F24S 2023/86 in the form of reflective coatings
• CPC Class Codes: F24S 23/71 with parabolic reflective surfaces with cylindro-parabolic reflective surfaces F24S23/74
• CPC Class Codes: F24S 23/82 characterised by the material or the construction of the reflector
• CPC Class Codes: H01Q 15/142 using insulating material for supporting the reflecting surface
• CPC Class Codes: H01Q 15/162 composed of a plurality of rigid panels
• CPC Class Codes: Y02E 10/40 Solar thermal energy, e.g. solar towers

Abstract

A reflector and method for making the same involves joining a set of curved reflective segments together to form a concave reflector having a focal point common to all of the segments. Each segment is conveniently a quarter section of the overall reflector, for example, and includes a pair of connecting plates arranged generally perpendicularly with respect to one another along its peripheral edges. The plates of adjacent segments may be joined together such that each segment and its associated plates are directed generally towards the common focal point. The various segments may be made by conventional plastic forming techniques and coated on one side thereof with reflective material.

Claims

1. An antenna including a segmented reflector for receiving radio frequency electromagnetic energy within a defined field of view and for substantially rejecting energy outside the field of view comprising:

at least two curved reflective segments joined together so that said segments have a common focal point, said segments defining a concave surface;

at least one radio frequency reflecting or attenuating connecting plate arranged between and connected to each of said segments, said plate directed toward said common focal point, said plate being disposed on said concave surface of said segments; and

means for receiving radio frequency energy reflected from said surface and not reflected or attenuated by said connecting plate, said receiving means disposed substantially only at said common focal point.

2. The antenna of claim 1 wherein four segments are joined together, each segment forming a quarter section of the reflector, said plates forming a pair of perpendicular walls intersecting along the focal line of said reflector.

3. The antenna of claim 1 wherein said segments are thermoformed plastic.

4. The antenna of claim 3 wherein said segments are vacuum thermoformed.

5. The antenna of claim 1 wherein said plates are formed integrally with said segments.

6. The antenna of claim 1 having a concave reflective surface.

7. The antenna of claim 1 wherein said segments are formed of metal coated plastic.

8. The antenna of claim 7 wherein said metal is vacuum deposited on said plastic to form a reflective surface thereon.

9. The antenna of claim 7 wherein a metal foil is deposited on said segment.

10. The antenna of claim 9 wherein a plastic film carrier is deposited on said metal foil, with said plastic film carrier facing outwardly of the segment.

11. The antenna of claim 10 wherein said carrier film is ultraviolet stabilized.

12. The antenna of claim 9 wherein a metal foil is bonded to said segment by a preapplied layer of pressure sensitive adhesive.

13. The antenna of claim 1 wherein said plate extends from the reflective surface of said segments a distance of less than about 70% of the focal length of said reflector.

14. The antenna of claim 13 wherein said plate extends beyond both sides of said segment.

15. The antenna of claim 1 including a central opening for reducing wind loading.

16. The antenna of claim 1 wherein said segments are formed of flexible sheet material.

17. The antenna of claim 1 wherein said plate is made of electrically insulative material, said plates electrically isolating said segments from one another.

18. The antenna of claim 17 wherein a portion of said plate extends over said reflective segments said portion of said plate including a reflective surface.

19. The antenna of claim 1 wherein electromagnetic energy received by said reflector substantially parallel to a line between said connecting plate and said focal point is reflected to said focal point by said reflective segments and at least some electromagnetic energy which is received substantially non-parallel with said line is reflected by said connecting plate away from said focal point or attenuated by said connecting plate.

20. A segmented reflector comprising:

at least two curved, flexible segments;

at least one electrically insulating connecting plate arranged between and connected to each of said segments;

a reflective surface, including a layer of metal foil laminated to one side of each of said segments, said segments connected to have a common focus, said connecting plate having an edge directed toward said common focal point and extending from said reflective surface a distance of less than about 70% of the focal length of said reflector.

21. The reflector of claim 20 wherein said reflective surface includes a transparent plastic film laminated on the outside of said reflective surface.

22. The reflector of claim 21 wherein said segments form a concave dish shape.

23. The reflector of claim 20 wherein the portion of said plate extending over said reflective surface is itself reflective.

24. The antenna of claim 22 wherein electromagnetic energy received by said reflector substantially parallel to a line between said connecting plate and said focal point is reflected to said focal point by said reflective segments and at least some electromagnetic energy which is received substantially non-parallel with said line is reflected by said connecting plate away from said focal point or attenuated by said connecting plate.

25. An antenna including a reflector for receiving radio frequency electromagnetic energy within a defined field of view and for substantially rejecting energy outside the field of view comprising:

a concave energy reflective surface, defining a focus, focal length and a focal line;

a pair of generally perpendicular, flat plates extending outwardly of said concave surface and intersecting one another generally on the focal line of said surface, each of said plates having a pair of opposed reflective side surfaces for reflecting radio frequency energy and a pair of opposed edges, one of said edges adjacent said concave reflective surface and the other of said edges directed generally toward said focus; and

means for receiving radio frequency energy reflected from said surface and not reflected or attenuated by said connecting plate, said receiving means disposed substantially only at said focus.

26. The antenna of claim 25 wherein said plates extend above the reflective surface a distance of less than 70% of the focal length.

27. The antenna of claim 25 wherein said reflective surface is made up of a plurality of electrically isolated reflective portions attached to said plates.

28. The antenna of claim 25 wherein said reflective surface is dish-shaped.

29. The reflector of claim 28 wherein said plate extends beyond both sides of said segment.

30. The antenna of claim 25 wherein electromagnetic energy received by said reflector substantially parallel to a line between said connecting plate and said focal point is reflected to said focal point by said reflective segments and at least some electromagnetic energy which is received substantially non-parallel with said line is reflected by said connecting plate away from said focal point.

31. A segmented reflector for electromagnetic energy comprising:

at least two curved reflective segments joined together so that said segments have a common focal point; and

at least one connecting plate arranged between and connected to each of said segments, said plate directed towards said common focal point and extending from the reflective surface of said segments a distance of less than about 70% of the focal length of said reflector.

32. The reflector of claim 31 wherein four segments are joined together, each segment forming a quarter section of the reflector, said plates forming a pair of perpendicular walls intersecting along the focal line of said reflector.

33. The reflector of claim 31 wherein said segments are thermoformed plastic.

34. The reflector of claim 33 wherein said segments are vacuum thermoformed.

35. The reflector of claim 31 wherein said plates are formed integrally with said segments.

36. The reflector of claim 31 having a concave reflective surface.

37. The reflector of claim 31 wherein said segments are formed of metal coated plastic.

38. The reflector of claim 37 wherein said metal is vacuum deposited on said plastic to form a reflective surface thereon.

39. The reflector of claim 37 wherein a metal foil is deposited on said segment.

40. The reflector of claim 39 wherein a plastic film carrier is deposited on said metal foil, with said plastic film carrier facing outwardly of the segment.

41. The reflector of claim 40 wherein said carrier film is ultraviolet stabilized.

42. The reflector of claim 39 wherein a metal foil is bonded to said segment by a preapplied layer of pressure sensitive adhesive.

43. The reflector of claim 31 including a central opening for reducing wind loading.

44. The reflector of claim 31 wherein said segments are formed of flexible sheet material.

45. The reflector of claim 31 wherein said plate is made of electrically insulative material, said plates electrically isolating said segments from one another.

46. The reflector of claim 45 wherein a portion of said plate extends over said reflective segments, said portion of said plate including a reflective surface.

47. The reflector of claim 31 wherein electromagnetic energy received by said reflector substantially parallel to a line between said connecting plate and said focal point is reflected to said focal point by said reflective segments and at least some electromagnetic energy which is received substantially non-parallel with said line is reflected by said connecting plate away from said focal point or attenuated by said connecting plate.

48. An energy reflector comprising:

a curved energy reflective surface, defining a focus, focal length and a focal line; and

a pair of generally perpendicular, flat plates extending outwardly of said surface and intersecting one another generally on the focal line of said surface, each of said plates having a pair of opposed reflective side surfaces and a pair of opposed edges, one of said edges adjacent said reflective surface and the other of said edges directed generally towards said focus, said flat plates extending above the reflective surface a distance of less than 70% of the focal length.

50. The reflector of claim 48 wherein said reflective surface is concave dish-shaped.

51. The reflector of claim 48 wherein electromagnetic energy received by said reflector substantially parallel to a line between said connecting plate and said focal point is reflected to said focal point by said reflective segments and at least some electromagnetic energy which is received substantially non-parallel with said line is reflected by said connecting plate away from said focal point or attenuated by said connecting plate.

52. An antenna including a reflector for receiving a radio frequency electromagnetic energy within a defined field of view and for substantially rejecting energy outside the field of view comprising:

a concave energy reflective surface defining a focus and a focal line;

a generally flat plate extending outwardly of said concave surface passing through the focal line of said surface, said plate having a pair of opposed radio frequency reflecting or attenuating side surfaces and a pair of opposed edges, one of said edges adjacent said concave reflective surface and the other of said edges directed generally towards said focus; and

means for receiving said radio frequency energy reflected from said surface and not reflected or attenuated by said connecting plate, said receiving means disposed substantially only at said focus.

49. The reflector of claim 54 wherein said reflective surface is made up of a plurality of electrically isolated reflective portions attached to said plates.

53. The antenna of claim 52 wherein said concave energy reflective surface comprises at least two curved reflective segments joined together so that said segments have said focus as a common focal point, and wherein said plate is arranged between and connected to each of said segments, said plate directed towards said common focal point.

54. The antenna of claim 53 wherein energy received by said reflector substantially parallel to a line between said connecting plate and said focal point is reflected to said focal point by said reflective segments and at least some electromagnetic energy which is received substantially non-parallel with said line is reflected by said connecting plate away from said focal point or attenuated by said connecting plate.