ANTENNA ARRAY AT FOCAL PLANE OF REFLECTOR WITH COUPLING NETWORK FOR BEAM SWITCHING

• US 3,569,976 A
• Filed: 08/29/1968
• Issued: 03/09/1971
• Est. Priority Date: 08/29/1968
• Status: Expired due to Term

• Current Assignee: Milton K. Mills, William Korvin
• Original Assignee: Milton K. Mills, William Korvin
• Inventors: Korvin, William, Mills, Milton K.
• Application Number:
  US04/759,256
• Time in Patent Office: 922 Days
• US Class Current: 343/777
• CPC Class Codes: H01Q 3/245 in the focal plane of a focussing device
• CPC Class Codes: H01Q 3/2658 Phased-array fed focussing structure

Abstract

An antenna system for steering plural beams from a secondary reflector is formed from a primary array of linear feed elements, which can be arranged in either a one- or two-dimensional configuration. By controlling which of the radiators are simultaneously excited with a switching matrix, the position of the primary beam is varied as a function of the axis of the reflector forming the secondary beam.

Claims

1. A system for controlling the position of a secondary radiation beam derived by reflection from a parabolic reflector having a bore sight axis comprising an array including several radiating elements arranged in the best fit focal plane of the reflector, means for simultaneously in phase exciting a plurality of adjacent ones of said elements so that the axis of the pattern is substantially at the center of the excited elements, said exciting means including means for maintaining said plurality of elements excited in phase throughout the interval while the pattern axis is at the center of the excited elements, said plurality being less than said several, said exciting means including switch means for selectively switching the excitation of different ones of said several elements to translate the pattern axis to a plurality of positions.

2. The system of claim 1 wherein said exciting means includes N-terminals, one for each of the pattern positions, N-power dividers, each of said dividers equally coupling power between a different one of said N-terminals and a plurality of ports, and means for connecting the plurality of ports of each divider in power-coupling relationship to adjacent ones of said elements, said switching means including means for connecting a load or source to each of said N-terminals.

3. The system of claim 1 wherein the elements are arranged in a single direction.

4. The system of claim 3 further including means for mechanically scanning said array about the center of the elements and on the boresight axis of a reflector forming the secondary beam.

5. The system of claim 3 wherein the switching means includes means for energizing only a pair of said elements simultaneously.

6. The system of claim 1 wherein each of said elements comprises a horn, said horns having increasing tapers as the separation thereof from the boresight axis of a reflector forming the secondary beam increases.

7. The system of claim 6 wherein said horns have increasing tapers along and at right angles to a longitudinal axis of the array.

8. The system of claim 6 wherein said horns have increasing tapers along a longitudinal axis of the array.

9. A system for controlling the position of a secondary radiation beam derived by reflection from a parabolic reflector having a boresight axis comprising an array including several radiating elements arranged to illuminate the reflector, means for simultaneously in phase exciting a plurality of adjacent ones of said elements so that the axis of the pattern is substantially at the center of the excited elements, said exciting means including means for maintaining said plurality of elements excited in phase throughout the interval while the pattern axis is at the center of the excited elements, said plurality being less than said several, said exciting means including switch means for selectively switching the excitation of different ones of said several elements to translate the pattern axis to a plurality of positions, said exciting means including several circulators, a different one of said circulators coupling energy with a different one of each of said elements via a first port of the circulator, each of said circulators including a plurality of other ports in energy exchange relationship with the respective elements via the first port, first and second networks, each of said networks including N-terminals, one for each of the pattern positions, N-power dividers, each of said dividers equally coupling power between a different one of said N-terminals and a plurality of ports;

means for connecting the plurality of ports of each divider of the first network in power-coupling relationship to one of the other ports of adjacent ones of said circulators, means for connecting the plurality of ports of each divider of the second network in power-coupling relationship to another of the other ports of adjacent ones of said circulators, said switching means including a first switching matrix for coupling power between a load and each of the N-terminals of the first network and a second switching matrix for coupling power between a source and each of the N-terminals of the second network.

10. The system of claim 9 wherein said first matrix includes means for coupling power between a plurality of loads and each of the N-terminals of the first network, and said second matrix includes means for coupling power between a plurality of sources and each of the N-terminals of the second network.

11. The system of claim 9 wherein said first matrix includes means for coupling power between a plurality of loads and each of the N-terminals of the first network.

12. The system of claim 9 wherein said second matrix includes means for coupling power between a plUrality of sources and each of the N-terminals of the second network.

13. The system of claim 9 wherein each of said matrices includes a plurality of ordered single-pole, double-throw switches, different orders of said switches being connected in series to provide a unique path to each of said terminals from the source and load.

14. The system of claim 9 wherein each of said second connecting means includes a single-pole, double-throw switch between a pair of said power dividers and one port of circulators coupling energy to adjacent pairs of said elements.

15. The system of claim 9 wherein the elements are arranged in a pair of directions at right angles to each other, and said means for exciting includes means for simultaneously exciting said elements in both said directions.

16. The system of claim 15 wherein said elements are approximately equispaced in N-columns of M-rows, where N and M are integers.

17. The system of claim 13 wherein said switches are frequency selective for coupling different frequencies between different ones of said sources and loads with said circulator ports.

18. The system of claim 13 wherein said switches are phase selective for coupling different phases between different ones of said sources and loads with said circulator ports.

19. The system of claim 9 wherein said first matrix includes means for coupling power between a plurality of loads and each of the N-terminals of the first network simultaneously with said second matrix coupling power between a plurality of sources and each of the N-terminals of the second network.

20. A system for electrically scanning a secondary radiation beam derived by reflection from a parabolic reflector having a boresight axis comprising an array including several radiating elements arranged in the best fit focal plane of the reflector, means for simultaneously in phase exciting a plurality of adjacent ones of said elements so that the axis of the pattern is substantially at the center of the excited elements, said exciting means including means for maintaining said plurality of elements excited in phase throughout the interval while the pattern axis is at the center of the excited elements, said exciting means including means for translating the pattern axis, said translating means including switch means for switching the excitation of said elements so that at least one element of said plurality remains excited while at least another element of said plurality is deactivated and at least one previously deactivated element is excited, said at least one previously deactivated element being adjacent to an element remaining excited.

21. The system of claim 20 wherein the elements are arranged in a single direction.

22. The system of claim 21 further including means for mechanically scanning said array about the center of the arranged elements and on the boresight axis of a reflector forming the secondary beam.

23. The system of claim 21 wherein the switching means includes means for energizing only a pair of said elements simultaneously.

24. The system of claim 20 wherein each of said elements comprise a horn, said horns having increasing tapers as the separation thereof from the boresight axis of a reflector forming the secondary beam increases.

25. The system of claim 24 wherein said horns have increasing tapers along and at right angles to a longitudinal axis of the array.

26. The system of claim 24 wherein said horns have increasing tapers along a longitudinal axis of the array.