Amplitude monopulse slotted array

• US 4,958,166 A
• Filed: 08/22/1988
• Issued: 09/18/1990
• Est. Priority Date: 08/22/1988
• Status: Expired due to Term

• Current Assignee: Raytheon Company (Rtx Corporation)
• Original Assignee: General Dynamics Corporation
• Inventors: Wronski, Michael W., Branigan, John T.
• Primary Examiner(s): Hille, Rolf
• Assistant Examiner(s): Le, Hoanganh
• Application Number:
  US07/196,696
• Time in Patent Office: 757 Days
• Field of Search: 343/771, 343/768, 343/858, 343/767, 343/850, 343/770
• US Class Current: 343/771
• CPC Class Codes: H01Q 13/10 Resonant slot antennas
• CPC Class Codes: H01Q 21/064 using horn or slot aerials slotted waveguides arrays H01Q21/005
• CPC Class Codes: H01Q 25/02 providing sum and difference patterns H01Q25/04 takes precedence

Abstract

An antenna system having first and second arrays of radiating members, first and second sets of corresponding bifurcated members and two pairs of feed members. The radiating members of the first and second arrays each have a near end and a far end and a linear portion therebetween with radiating slots formed therein. The linear portions of the radiating members are interleaved in a planar spaced parallel relationship. Each bifurcated member has a unitary portion and a bifurcated portion with the bifurcated portion having a pair of coupling ends. Each bifurcated member is coupled at its unitary portion to the near end of a different radiating member of its corresponding array and also coupled at its coupling ends to a different feed member of its corresponding pair of feed members. The antenna system further includes a monopulse comparator coupled to the input ends of the first and second pairs of feed members for operation as an amplitude comparison monopulse antenna.

Claims

1. A traveling have antenna having a far field antenna of pattern substantially four separate beams, comprising:

a first array of radiating waveguides, each of said first array radiating waveguides having a near end and a far end, with radiating slots formed therebetween;

a second array of radiating waveguides, each of said second array radiating waveguides having a near end and a far end with radiating slots formed therebetween, said first and second array radiating slots interleaved in a planar spaced parallel relationship, the near end of said first array and the near end of said second array lying substantially in a common plane orthogonal to a plane defined by said first and second arrays;

first and second pairs of feed waveguides corresponding to said first and second arrays of radiating waveguides, each of said feed waveguides having an input end and a load end, and coupled therebetween to the near end of each of said corresponding array of radiating waveguides, each radiating waveguide coupled to a certain one of said feed waveguides being identically coupled to said certain feed waveguide, wherein the energy coupled through each one of said feed waveguides is generally associated with a different one of said separate beans.

2. The antenna of claim 1 further comprising:

a first plurality of pieces of RF absorbing material each mounted at the far end of each radiating waveguide; and

a second plurality of pieces of RF absorbing material each mounted at the load end of each feed waveguide.

3. The antenna of claim 1 further comprising a monopulse comparator to the input ends of said first and said second pairs of feed waveguides.

4. The antenna of claim 3 wherein said monopulse comparator comprises first, second, third, and fourth hybrid tees, each of said hybrid tees having a pair of symmetry arms, a sum arm and a difference arm, said first hybrid tee symmetry arms each respectively coupled to the input end of said first pair of feed waveguides, said second hybrid tee symmetry arms each selectively coupled to the input end of said second pair of feed waveguides, wherein the energy coupled through each one of said symmetry arms of said first and second hybrid tees is generally associated with a different one of said separate beams, said third hybrid tee symmetry arms respectively coupled to said first and second hybrid tees difference arms, and said fourth hybrid tee symmetry arms respectively coupled to said first and second hybrid tees sum arms.

5. The antenna of claim 1 wherein said radiating slots are formed in a linear portion along the longitudinal axis of each of said radiating waveguides with said linear portions defining a planar array.

6. The antenna of claim 5 further comprising a monopulse comparator having first, second, third and fourth hybrid tees, each of said hybrid tees having a pair of symmetry arms, a sum arm and a difference arm, said first hybrid tee symmetry arms each respectively coupled to the input end of said first pair of feed waveguides, said second hybrid tee symmetry arms each respectively coupled to the input end of said second pair of feed waveguides, wherein the energy coupled through each one of said symmetry arms of said first and second hybrid tees is generally associated with a different one of said separate beams, said third hybrid tee symmetry arms respectively coupled to said first and second hybrid tees difference arms, and said fourth hybrid tee symmetry arms respectively coupled to said first and second hybrid tees sum arms.

7. A tracking system antenna having a far field antenna pattern substantially comprising four separate beams comprising:

a first array of radiating members, each of said first array radiating members having a near end, a far end and a linear portion with radiating slots formed therein;

a second array of radiating members, each of said second array radiating members having a near end, a far end and a linear portion with radiating slots formed therein, said linear portions of said first and said second array radiating members interleaves in a planar spaced parallel relationship, the near end of said first array and the near end of said second array lying substantially in a common plane orthogonal to a plane defined by said first and second arrays;

two sets of bifurcated members, each member having a unitary portion and a bifurcated portion with a pair of coupling ends, each of said first set of bifurcated members being coupled at a corresponding unitary portion to the near end of a different radiating member of said first array and each of said second set of bifurcated members being coupled at a corresponding unitary portion to the near end of a different radiating member of said second array; and

first and second pairs of feed members, each feed member of said first pair of feed members being respectively coupled to a different coupling end of each of said first set of said bifurcated members and each feed member of said second pair of feed members being respectively coupled to a different coupling end of each of said second set of said bifurcated members each bifurcated member coupled to a certain one of said feed members being identically coupled to said certain feed member, wherein the energy coupled through each one of said feed members is generally associated a different one of said separate beams.

8. The antenna of claim 7 further comprising:

a first plurality of edges of RF absorbing material each mounted at the far end of each radiating member; and

a second plurality of wedges of RF absorbing material each mounted at the load end of each feed member.

9. The antenna of claim 7 further comprising a monopulse comparator having first, second, third and fourth hybrid tees, each of said hybrid tees having a pair of symmetry arm members, a sum arm member and a difference arm member, said first hybrid tee symmetry arm members each respectively coupled to one end of a different feed member of said first pair of feed members with said second hybrid tee symmetry arm members each respectively coupled to one end of a different feed member of said second pair of feed members wherein the energy coupled through each one of said symmetry arms of said first and second hybrid tees is generally associated with a different one of said beams, said third hybrid tee symmetry arm members respectively coupled to said first and second hybrid tees difference arm members, said fourth hybrid tee symmetry arm members respectively coupled to said first and second hybrid tees sum arm members.

10. A tracking system antenna having a far field antenna pattern of substantially four separate beams, comprising:

a first array of rectangular radiating waveguides, each of said first array radiating waveguides having a near end, a far end and a linear portion with edge radiating slots formed therebetween;

a second array of rectangular radiating waveguides, each of said second array radiating waveguides having a near end, a far end and linear portion with radiating slots formed therebetween, said linear portions of said first and said second array radiating waveguides interleaved in a planar spaced parallel relationship, the near end of said first array and the near end of said second array lying substantially in a common plane orthogonal to a plane defined by said first and second arrays;

two sets of rectangular bifurcated waveguides, each of said bifurcated waveguides having a unitary portion and a bifurcated portion with a pair of coupling ends, each of said first set of said bifurcated waveguides being coupled at a corresponding unitary portion to the near end of a different radiating waveguide of said first array and each of said second set of said bifurcated waveguides being coupled at a corresponding unitary portion to the near end of a different radiating waveguide of said second array; and

first and second pairs of rectangular feed waveguides, each feed waveguide of said first pair of feed waveguides being respectively coupled to a different coupling end of each one of said first set of said bifurcated waveguides, and each feed waveguide of said second pair of feed waveguides being coupled to a different coupling end of each one of said second set of said bifurcated waveguides, each bifurcated waveguide coupled to a certain one of said feed waveguides being identically coupled to said certain feed waveguide, wherein the energy coupled through each one of said feed waveguides is generally associated a different one of said separate beams.

11. The antenna of claim 10 further comprising:

a first plurality of edges of RF absorbing material each mounted at the far end of each radiating member; and

a second plurality of edges of RF absorbing material each mounted at the load end of each feed member.

12. The antenna of claim 10 further comprising a monopulse comparator having first, second, third and fourth hybrid tees, each of said hybrid tees having a pair of waveguide symmetry arms, a waveguide sum arm and a waveguide difference arm, said first hybrid tee symmetry arms each respectively coupled to the input end of said first pair of rectangular feed waveguides, said second hybrid tee symmetry arms each respectively coupled to the input end of said second pair of rectangular feed waveguides, wherein the energy coupled through each one of said symmetry arms of said first and second hybrid tees is generally associated with a different one of said separate beams, said third hybrid tee symmetry arms respectively coupled to said first and second hybrid tees difference arms, and said fourth hybrid tee symmetry arms respectively coupled to said first and second hybrid tees sum arms.