Horn antenna array and methods for fabrication thereof

• US 7,193,578 B1
• Filed: 10/07/2005
• Issued: 03/20/2007
• Est. Priority Date: 10/07/2005
• Status: Active Grant

• Current Assignee: Lockheed Martin Corporation (Martin Marietta Corporation)
• Original Assignee: Lockheed Martin Corporation (Martin Marietta Corporation)
• Inventors: Harris, Daniel W., Hahn, Joseph W.
• Primary Examiner(s): Dinh; Trinh
• Assistant Examiner(s): MANCUSO, HUEDUNG XUAN CAO
• Application Number:
  US11/245,831
• Time in Patent Office: 529 Days
• Field of Search: 343/767, 343/770, 343/700.MS, 343/768, 343/790
• US Class Current: 343/767
• 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 13/085 Slot-line radiating ends
• CPC Class Codes: H01Q 21/064 using horn or slot aerials slotted waveguides arrays H01Q21/005

Abstract

A method for making a horn antenna array includes the steps of making first and second equal-size printed-circuit half-horn-elements, and offset-juxtaposing element pairs to make horn elements having a dielectric lip or step. A ground plane defining mutually intersecting crossed slot sets is loaded with horn elements with their lips interlocking near the slot crossings, to define the horn antenna array. The horn elements can be fed by pins extending through portions of the ground plane and into an aperture adjacent the feed elements of the horn elements. Electrical connections are made by fusion joining after the array is assembled.

Claims

1. A method for making a horn antenna, said method comprising the steps of:

fabricating a dielectric first board defining first and second broad sides, and also having at least a first transverse dimension adjacent a feed end of said first board, said first board defining a conductive horn on said first broad side thereof and a feed structure on said second broad side thereof adjacent said feed end of said first board, said feed structure including a strip conductor adjacent said feed end of said first board;

fabricating a dielectric second board defining first and second broad sides, and also having at least said first transverse dimension adjacent a feed end of said second board, said second board defining on said first broad side a conductive horn including a feed region adjacent said feed end of said second board, said second board defining an aperture which is registered with said strip conductor when said second broad side of said first board is offset-juxtaposed with said second broad side of said second board;

offset-juxtaposing said second broad side of said first board with said second broad side of said second board, with said strip conductor feed structure adjacent said aperture, and an offset between lateral edges of said first and second boards, to thereby generate a single horn element.

2. A method according to claim 1, wherein:

said dielectric first and second boards have the same thickness, and said offset between lateral edges of said first and second boards is equal in magnitude to the thickness of one of said first and second boards.

3. A method according to claim 2, further comprising the step of affixing said offset-juxtaposed second broad side of said first board to said second broad side of said second board.

4. A method according to claim 3, wherein said step of affixing includes application of fluid adhesive substance to at least one of said second broad side of said first board to said second broad side of said second board.

5. A method according to claim 4, wherein said step of application of fluid adhesive substance includes the step of application of a hardenable fluid adhesive substance.

6. A method according to claim 5, wherein said step of application of a hardenable fluid adhesive substance includes the step of application of a curable resin.

7. A method according to claim 3, wherein said step of step of affixing said offset-juxtaposed second broad side of said first board to said second broad side of said second board comprises the step of fusion-bonding said offset-juxtaposed second broad side of said first board to said second broad side of said second board.

8. A method for making a horn antenna, said method comprising the steps of:

procuring a dielectric first board defining first and second broad sides and a board thickness, and also having at least a first transverse dimension adjacent a feed end of said first board, said first board defining a conductive horn on said first broad side thereof and a feed structure on said second broad side thereof adjacent said feed end of said first board, said feed structure including a strip conductor adjacent said feed end of said first board;

procuring a dielectric second board defining first and second broad sides and a board thickness, and also having at least said first transverse dimension adjacent a feed end of said second board, said second board defining on said first broad side a conductive horn including a feed region adjacent said feed end of said second board, said second board defining an aperture which is registered with said strip conductor when said second broad side of said first board is offset-juxtaposed with said second broad side of said second board;

juxtaposing said second broad side of said first board with said second broad side of said second board, with said strip conductor feed structure adjacent said aperture, to thereby generate a horn element;

procuring a conductive support plate defining first and second broad surfaces, and a plurality of elongated slots depressed below said first broad surface, said plurality of slots including first and second sets of slots, the directions of elongation of which are mutually orthogonal, the individual slots of said first and second sets defining a width accommodating the combined thicknesses of said first and second boards, said individual slots of said first and second sets being mutually parallel and spaced apart by a dimension at least equal to said transverse dimension, said conductive support plate further supporting a plurality of electrically conductive pins, electrically insulated from said support plate, said pins extending at least partially through said plate between said first and second broad sides, and projecting into said slots at locations registered with said strip conductors when said horn elements are mounted in said slots in such a manner that said pins lie adjacent the corresponding strip conductor;

inserting the feed end of said horn element into a corresponding slot of said conductive support plate with said strip conductor registered to be adjacent the corresponding pin; and

electrically connecting said pin to said strip conductor.

9. A method according to claim 8, wherein said step of juxtaposing said second broad side of said first board with said second broad side of said second board, with said strip conductor feed structure adjacent said aperture, to thereby generate a horn element, further comprises the step of bonding said second broad side of said first board with said second broad side of said second board.

10. A method according to claim 9, wherein said step of bonding comprises the step of fusion bonding.

11. A method according to claim 9, wherein said step of bonding comprises the step of application of the liquid state of an adhesive substance.

12. A method according to claim 11, wherein said step of application of the liquid state of an adhesive substance comprises the step of application of the liquid state of a curable resin.

13. A method for making a horn array, said method comprising the steps of:

procuring a dielectric first board defining first and second broad sides, a board thickness, and first and second lateral edges, and also having at least a first transverse dimension adjacent a feed end of said first board, said first board defining a horn on said first broad side thereof and a feed structure on said second broad side thereof adjacent said feed end of said first board, said feed structure including a strip conductor adjacent said feed end of said first board;

procuring a dielectric second board defining first and second broad sides, a board thickness, and first and second lateral edges, and also having at least said first transverse dimension adjacent a feed end of said second board, said second board defining on said first broad side a horn including a feed region adjacent said feed end of said second board, said second board defining an aperture which is registered with said strip conductor when said second broad side of said first board is offset-juxtaposed with said second broad side of said second board;

offset-juxtaposing said second broad side of said first board with said second broad side of said second board, with said strip conductor feed structure adjacent said aperture, and with the lateral edges offset by said thickness, to thereby generate a horn antenna element;

repeating said steps of procuring a dielectric first board, procuring a dielectric second board, and offset-juxtaposing of said boards, until at least four horn antenna elements are available;

procuring a conductive support plate defining first and second broad surfaces, and a plurality of elongated slots depressed below said first broad surface, said plurality of slots including first and second sets of slots, the directions of elongation of which are mutually orthogonal, the individual slots of said first and second sets defining a width accommodating the combined thicknesses of said first and second boards of a horn antenna element, said individual slots of said first and second sets being mutually parallel and spaced apart by a dimension about equal to the sum of said transverse dimension plus said thickness of one of said first and second boards, said conductive support plate further supporting a plurality of electrically conductive pins, electrically insulated from said support plate, said pins extending at least partially through said plate between said first and second broad sides, and projecting into said slots at locations registered with said strip conductors when said horn elements are mounted in said slots in such a manner that said pins lie adjacent the corresponding strip conductor;

inserting the feed end of at least first, second, third, and fourth of said horn antenna elements into a pair of mutually orthogonal corresponding slots of said conductive support plate with said strip conductors registered to be adjacent the corresponding pins and with said offsets of said first, second, third and fourth horn antenna elements mating; and

electrically connecting said pins to said strip conductors.

14. A method for making a horn array, said method comprising the steps of:

procuring a dielectric first board defining first and second broad sides, a board thickness, and first and second lateral edges, and also having at least a first transverse dimension adjacent a feed end of said first board, said first board defining a conductive-slot horn on said first broad side thereof and a feed structure on said second broad side thereof adjacent said feed end of said first board, said feed structure including a strip conductor adjacent said feed end of said first board;

procuring a dielectric second board defining first and second broad sides, a board thickness, and first and second lateral edges, and also having at least said first transverse dimension adjacent a feed end of said second board, said second board defining on said first broad side a conductive-slot horn including a feed region adjacent said feed end of said second board, said second board defining an aperture which is registered with said strip conductor when said second broad side of said first board is offset-juxtaposed with said second broad side of said second board;

offset-juxtaposing said second broad side of said first board with said second broad side of said second board, with said strip conductor feed structure adjacent said aperture, and with the lateral edges offset by said thickness, to thereby generate a conductive-slot horn antenna element defining a radiating end opposite to said feed end;

repeating said steps of procuring a dielectric first board, procuring a dielectric second board, and offset-juxtaposing of said boards, until at least four horn antenna elements are available;

procuring a conductive support plate defining first and second broad surfaces, and a plurality of elongated slots depressed below said first broad surface, said plurality of slots including first and second sets of slots, the directions of elongation of which are mutually orthogonal, the individual slots of said first and second sets defining a width accommodating the combined thicknesses of said first and second boards of a horn antenna element, said individual slots of said first and second sets being mutually parallel and spaced apart by a dimension about equal to the sum of said transverse dimension plus said thickness of one of said first and second boards, said conductive support plate further supporting a plurality of electrically conductive pins, electrically insulated from said support plate, said pins extending at least partially through said plate between said first and second broad sides, and projecting into said slots at locations registered with said strip conductors when said horn elements are mounted in said slots in such a manner that said pins lie adjacent the corresponding strip conductor;

inserting the feed end of at least first, second, third, and fourth of said conductive-slot horn antennas elements into a pair of mutually orthogonal corresponding slots of said conductive support plate with said strip conductors registered to be adjacent the corresponding pins and with said offsets of said first, second, third and fourth horn antenna elements mating; and

electrically connecting said pins to said strip conductors and said conductive portions of said conductive slot horns to adjacent ones of said conductive portions of said conductive slots, to thereby define an array including two pairs of mutually orthogonal conductive horn antenna elements.

15. A method according to claim 14, further comprising, between said steps of inserting the feed end and electrically connecting, the step of:

affixing a jig to said radiating end of said conductive horn antenna elements to hold the radiating ends of said horn antenna elements in the same dimensional relationship as that provided to said feed ends by said slots of said support plate.

16. A method according to claim 14, wherein said jig includes a material which is not wetted by a fusion material, and wherein said step of electrically connecting further comprises the step of heating said two pairs of mutually orthogonal conductive horn antenna elements and said conductive support plate in the presence of fusion material.

17. A method according to claim 16, wherein said fusion material is solder, and said material is graphite.

18. A method according to claim 14, further comprising repeating said steps of (a) procuring a dielectric first board, (b) procuring a dielectric second board, (c) offset-juxtaposing to thereby generate a conductive-slot horn antenna element, (d) repeating, (e) procuring a conductive support plate, and (f) inserting the feed end, until slot locations having said pins are all populated, and only when all slot locations are so populated performing said step of electrically connecting.

19. A method for making a horn antenna comprises the steps of:

procuring a planar horn antenna defining a planar feed conductor located within an aperture adjacent the feed end of said horn antenna;

procuring an electrically conductive support structure defining an elongated slot having sides and a bottom, said sides and bottom being dimensioned to accommodate said feed end of said horn antenna, said support structure further defining an electrically conductive coaxial conductor extending in an electrically insulated manner through said support structure, and having a portion of said coaxial conductor extending outwardly from the bottom of said slot;

mounting said planar horn antenna in said slot with said portion of said coaxial conductor extending into said aperture adjacent said feed conductor; and

making an electrical connection between said portion of said coaxial conductor and said planar feed conductor.