Impulse radar antenna array and method

• US 6,922,177 B2
• Filed: 02/26/2002
• Issued: 07/26/2005
• Est. Priority Date: 02/26/2001
• Status: Active Grant

• Current Assignee: Humatics Corporation
• Original Assignee: Time Domain Corporation (Humatics Corporation)
• Inventors: Nag, Soumya K., Gilbert, Charles G., Barnes, Mark A., Dickson, David M., Fluhler, Herbert U., Schantz, Hans G.
• Primary Examiner(s): Vannucci, James
• Application Number:
  US10/083,689
• Publication Number:
  US 20020190915A1
• Time in Patent Office: 1,246 Days
• Field of Search: 343/893, 343/700.MS, 343/778, 343/770, 343/745
• US Class Current: 343/893
• CPC Class Codes: G01S 13/0209 Systems with very large relative bandwidth, i.e. larger than 10 %, e.g. baseband, pulse, carrier-free, ultrawideband
• CPC Class Codes: G01S 13/888 through wall detection
• CPC Class Codes: H01Q 1/38 formed by a conductive layer on an insulating support patch antennas H01Q9/0407; microstrip dipole antennas H01Q9/065; microstrip slot antennas H01Q13/106; transmission line microstrip antennas H01Q13/206; manufacturing reflecting surfaces using insulating material for supporting the reflecting surface H01Q15/142
• CPC Class Codes: H01Q 1/525 between emitting and receiving antennas
• CPC Class Codes: H01Q 21/08 the units being spaced along or adjacent to a rectilinear path waveguide fed H01Q21/0037

Abstract

An antenna array comprising a ground plane and a plurality of elements mounted thereon, said elements being capable of emitting and receiving ultra wideband emissions. Elements are arrayed on the ground plane in two parallel rows, a transmitting row, and a receiving row, such that a given element in the receiving row is aligned in at least one direction with a corresponding element in the transmitting row. Additionally, the elements are configured on the ground plane to elicit a symmetrical product response in the azimuthal plane, and to produce horizontally polarized signals. An alternative embodiment places the elements with unique inter-element spacing within the rows. An embodiment comprises a fence structure between rows. A method for use comprises the step of transmitting a signal via an element in the transmitting row and receiving said signal through an element in the receiving row, not aligned with the transmitting element.

Claims

1. An impulse radar antenna array comprising:

a. a ground plane, comprising a first surface and a second surface; and

b. a plurality of antenna elements affixed to said first surface, each of said plurality of antenna elements being adapted to emit and receive ultra wideband signals;

said plurality of antenna elements being disposed in parallel rows upon said first surface, said parallel rows comprising a transmitting row of transmitting elements adapted to emit ultra wideband signals and a receiving row of receiving elements adapted to receive ultra wideband signals impingent thereon;

said receiving elements being equal in number to said transmitting elements and disposed in said receiving row such that each of said receiving elements is aligned with respect to a corresponding transmitting element disposed in said transmitting row;

each of said receiving elements being oriented upon said first surface with respect to said corresponding transmitting element so as to create a symmetric product response with respect to aspect angle.

2. The impulse radar antenna array of claim 1, further comprising a radome, said radome comprising a surface having a departure;

said departure describing a hollow such that when said radome overlays said transmitting row, radiated energy from said transmitting row is normal to said hollow.

3. The impulse radar antenna array of claim 2, wherein said radome is comprised of a low density, low dielectric, thermo/vacuum-formable material.

4. The impulse radar antenna array of claim 2, wherein said radome further comprises an acoustic damping means.

5. The impulse radar antenna array of claim 2, wherein said radome further comprises at least one stand-off.

6. The impulse radar antenna array of claim 5, wherein said stand-off is comprised of acoustic damping material.

7. The impulse radar antenna array of claim 2, wherein said radome further comprises at least one stand-off.

8. An impulse radar antenna array comprising:

a. a ground plane, comprising a first surface and a second surface; and

b. a plurality of antenna elements affixed to said first surface, each of said plurality of antenna elements being adapted to emit and receive ultra wideband signals;

said plurality of antenna elements being disposed in parallel rows upon said first surface, said parallel rows comprising a transmitting row of transmitting elements adapted to emit ultra wideband signals and a receiving row of receiving elements adapted to receive ultra wideband signals impingent thereon;

said transmitting row being disposed along a line parallel to a longitudinal axis of said first surface such that said each transmitting element comprising said transmitting row is alternatingly displaced laterally from said line.

9. The impulse radar antenna array of claim 8, wherein said receiving row is disposed along a line parallel to a longitudinal axis of said first surface such that said each receiving element comprising said receiving row is alternatingly displaced laterally from said line.

10. The impulse radar antenna array of claim 9, wherein said antenna elements are affixed to said first surface such that each of said elements in each of said rows is obliquely oriented with respect to a neighboring element within said row.

11. An impulse radar antenna array comprising:

a. a ground plane, comprising a first surface and a second surface;

b. a plurality of antenna elements affixed to said first surface, each of said plurality of antenna elements being adapted to emit and receive ultra wideband signals;

said plurality of antenna elements being disposed in parallel rows upon said first surface, said parallel rows comprising a transmitting row of transmitting elements adapted to emit ultra wideband signals and a receiving row of receiving elements adapted to receive ultra wideband signals impingent thereon;

each of said plurality of antenna elements including a tab; and

c. a plurality of wave guides disposed upon and co-planar with said second surface coupled to each of said plurality of antenna elements through said ground plane via said tabs;

said plurality of wave guides being comprised of transmission wave guides coupled to each of said transmitting elements, and receiving wave guides coupled to each of said receiving elements;

each of said transmitting wave guides being of substantially unique length.

12. The impulse radar antenna array of claim 11, wherein any of said receiving wave guides coupled to any of said receiving elements is equal in length to the transmitting wave guide coupled to the corresponding transmitting element.

13. The impulse radar antenna array of claim 11, wherein each of said wave guides coupled to said receiving antenna elements is equal in length to a wave guide coupled to said transmitting antenna elements.

14. The impulse radar antenna array of claim 13, further comprising a fence structure between said transmitting row and said receiving row.

15. The impulse radar antenna array of claim 14, wherein said fence structure describes a curvi-linear surface.

16. The impulse radar antenna array of claim 14, wherein said ground plane comprises at least one means to reduce backlobe radiation.

17. The impulse radar antenna array of claim 16, wherein said means of reducing backlobe radiation is rolled edges of said ground plane.

18. The impulse radar antenna array of claim 17 wherein said radome further comprises a cylindrical departure, said cylindrical departure adapted to receive said transmitting row in a hollow formed by said first cylindrical departure such that signals radiating therefrom strike said departure at a normal angle.

19. The impulse radar antenna array of claim 18, wherein said transmitting antenna elements are oriented upon said ground plane with respect to said receiving antenna elements such as to create a symmetric product response in the azimuthal plane.

20. The impulse radar antenna array of claim 19, further comprising a dummy element affixed to said ground plane at each end said transmitting row and said receiving row.

21. The impulse radar antenna array of claim 20, wherein said transmitting antenna elements and said receiving antenna elements are affixed to said ground plane such as to effect a horizontally polarized response.

22. The impulse radar antenna array of claim 16, wherein said means of reducing backlobe radiation is non-linear edges of said ground plane.

23. The impulse radar antenna array of claim 16, wherein said means of reducing backlobe radiation is fence structures mounted to the edges of said ground plane.

24. The radar antenna array of claim 16 wherein said means of reducing backlobe radiation is a ground plane comprising serrations of the edges of said ground plane.

25. A method for using an antenna array, said antenna array being comprised of a row of transmitting antenna elements and a row of receiving antenna elements parallel to said row of transmitting antenna elements, said receiving antenna elements being arrayed such that any receiving antenna element comprising said row of receiving antenna elements is aligned with a corresponding transmitting antenna element in a plane perpendicular to said transmitting and receiving rows and a means for controlling signal emission from each transmitting antenna element and signal reception to each receiving antenna element, comprising the step of receiving via any of said receiving antenna elements a signal emitted from any non-corresponding transmitting antenna element.

26. The method according to claim 25, further comprising the step of receiving via a receiving antenna element a signal emitted from said corresponding transmitting antenna element.

27. A method for using an antenna array, said antenna array being comprised of a row of transmitting antenna elements and a row of receiving antenna elements parallel to said row of transmitting antenna elements, said receiving antenna elements being arrayed such that any receiving antenna element comprising said row of receiving antenna elements is aligned with a corresponding transmitting antenna element in a plane perpendicular to said transmitting and receiving rows and a means for controlling signal emission from each transmitting antenna element and signal reception to each receiving antenna element, comprising the steps of:

a. emitting a signal from at least one transmitting antenna element; and

b. receiving said signal by at least one non-corresponding receiving antenna element.

28. The method according to claim 27, further comprising the steps of:

a. emitting a signal from at least one transmitting antenna element; and

b. receiving said signal by a corresponding receiving antenna element.

29. A radar antenna array comprising:

a. a ground plane, said ground plane having an axis, a first surface and a second surface;

b. a transmitting row comprised of transmitting antenna elements affixed to said first surface parallel to said axis;

c. a receiving row comprised of receiving antenna elements affixed to said first surface parallel to said axis;

said transmitting elements and said receiving elements being disposed within said transmitting row and said receiving row, respectively, such that inter-element spacing is substantially unique; and

d. a plurality of co-planar wave guides affixed with said second surface, each of said plurality of wave guides being coupled to each transmitting antenna element and to each receiving antenna element through said ground plane and wherein each of said antenna elements includes a feed tab for coupling to said wave guides;

said wave guides coupled to said transmitting antenna elements being of substantially unique lengths.

30. The radar antenna array of claim 29, wherein each of said wave guides coupled to said receiving antenna elements is equal in length to a wave guide coupled to said transmitting antenna elements.

31. The radar antenna array of claim 30, further comprising a fence structure between said transmitting row and said receiving row.

32. The radar antenna array of claim 31, wherein said fence structure describes a curvi-linear surface.

33. The radar antenna array of claim 30, wherein the radar antenna array further comprising a radome, said radome comprising a surface having a departure;

said departure describing a hollow such that when said radome overlays said transmitting row, radiated energy from said transmitting row is substantially normal to said hollow;

said radome further comprising at least one stand-off.

34. The radar antenna array of claim 30, wherein said ground plane comprises at least one means to reduce backlobe radiation.

35. The radar antenna array of claim 34, wherein said means of reducing backlobe radiation is rolled edges of said ground plane.

36. The radar antenna array of claim 34, wherein said radome further comprises a cylindrical departure, said cylindrical departure adapted to receive said transmitting row in a hollow formed by said first cylindrical departure such that signals radiating therefrom are incident said hollow at a normal angle.

37. The radar antenna array of claim 36, wherein said transmitting antenna elements are oriented upon said ground plane with respect to said receiving antenna elements such as to create a symmetric product response in the azimuthal plane.

38. The radar antenna array of claim 37, further comprising a dummy element affixed to said ground plane at each end said transmitting row and said receiving row.

39. The radar antenna array of claim 38, wherein said transmitting antenna elements and said receiving antenna elements are affixed to said ground plane such as to effect a horizontally polarized response.

40. The radar antenna array of claim 34, wherein said means of reducing backlobe radiation is non-linear edges of said ground plane.

41. The radar antenna array of claim 34, wherein said means of reducing backlobe radiation is fence structures mounted to the edges of said ground plan.

42. The radar antenna array of claim 34, wherein said means of reducing backlobe radiation is a ground plane comprising serrations of the edges of said ground plane.