Magnetic beam deflection devices

• US 6,429,803 B1
• Filed: 07/31/2000
• Issued: 08/06/2002
• Est. Priority Date: 12/17/1997
• Status: Expired due to Fees

• Current Assignee: BAE Systems Plc
• Original Assignee: BAE Systems Electronics Limited (BAE Systems Plc)
• Inventors: Kumar, Balbir
• Primary Examiner(s): Gregory, Bernarr E.
• Application Number:
  US09/581,598
• Time in Patent Office: 736 Days
• Field of Search: 342/70, 342/71, 342/72, 342/368-377, 342/73-81, 342/147, 342/149, 342/155-158, 343/700.MS, 343/711, 343/713, 343/715, 343/745, 343/746, 343/787, 333/24.1, 333/24.2, 333/24.3, 333/156, 333/157-164
• US Class Current: 342/70
• CPC Class Codes: H01Q 3/44 varying the electric or magnetic characteristics of reflecting, refracting, or diffracting devices associated with the radiating element

Abstract

A device for changing the divergence of a beam of microwave radiation comprises a ferrite body having an aperture through which the beam passes. Magnetic wires pass both through the body and across the aperture, or a magnetic coil on either side of the aperture, causes a differential phase delay as the beam passes through the aperture which broadens or narrows the beam.

Claims

1. A device for changing the divergence of a beam of electromagnetic radiation, comprising:

a structure having an internal opening that extends through the structure, and an electromagnetic aperture through which the beam passes; and

magnetic means extending through the internal opening in the structure, for controlling a width of the beam by generating a magnetic gradient across the electromagnetic aperture and producing a differential phase delay across different regions of the electromagnetic aperture.

2. The device according to claim 1, wherein the phase delay at a central region of the electromagnetic aperture has a magnitude which is greater than a magnitude of a phase delay at a periphery region of the electromagnetic aperture.

3. The device according to claim 1, wherein the phase delay at a central region of the electromagnetic aperture has a magnitude which is less than a magnitude of a phase delay at a periphery region of the electromagnetic aperture.

4. The device according to claim 1, wherein the structure is a ferrite body having additional openings extending through the structure, and wherein the magnetic means includes electrical current—

carrying wires located within the openings.

5. The device according to claim 1, wherein the structure includes a body and end parts at opposite ends of the body, and wherein the internal opening extends through one of the end parts, and further comprising another internal opening extending through the other of the end parts, and wherein the magnetic means includes electrical current—

carrying coils extending through the internal openings.

6. A device for changing the divergence of a beam of electromagnetic radiation, comprising:

a structure having an internal opening that extends through the structure, and an electromagnetic aperture having a plurality of sub-apertures through which the beam passes; and

magnetic means including a plurality of elements respectively associated with the sub-apertures, each element defining a boundary of its associated sub-aperture, at least one element extending through the internal opening in the structure, for controlling a width of the beam by generating a magnetic gradient across the electromagnetic aperture and producing a differential phase delay across different regions of the electromagnetic aperture.

7. The device according to claim 6, wherein the magnetic means is operative for inducing variations in a magnitude of magnetization present across the electromagnetic aperture.

8. The device according to claim 6, wherein the magnetic means is operative for inducing variations in a value of magnetization present across each sub-aperture.

9. The device according to claim 6, wherein said at least one element comprises at least one elongate source of a magnetic field.

10. The device according to claim 6, wherein the plurality of elements comprise elongate sources of magnetic fields disposed parallel to one another.

11. The device according to claim 6, wherein each element includes at least one path for carrying electric current.

12. The device according to claim 11, wherein the magnetic means is operative for altering the current carried by said at least one path to change a magnitude of a magnetic field generated by the magnetic means and thus a magnetization induced in the structure.

13. The device according to claim 6, wherein the magnetic means is in a form of a grid comprising a first set of an elongate source of magnetic field and a second set of an elongate source of magnetic field, and wherein the first set is oriented at an angle of greater than 0°

relative to the second set.

14. The device according to claim 13, wherein the magnetic means is operative for independently controlling a magnitude of a magnetic field of each of the first and second sets in order to broaden the beam width independently in azimuth and elevation directions.

15. The device according to claim 6, wherein said at least one element is located adjacent at least one side of the electromagnetic aperture.

16. The device according to claim 15, wherein there are two elements.

17. The device according to claim 16, wherein the two elements are provided in at least one pair on opposite sides of the electromagnetic aperture.

18. The device according to claim 6, wherein the beam of radiation is microwave radiation.

19. The device according to claim 6, wherein the beam of radiation is of millimeter wavelength radiation.

20. A control system, comprising a radar system incorporating a device for changing the divergence of a beam of electromagnetic radiation, comprising:

a structure having an internal opening that extends through the structure, and an electromagnetic aperture through which the beam passes; and

magnetic means extending through the internal opening in the structure, for controlling a width of the beam by generating a magnetic gradient across the electromagnetic aperture and producing a differential phase delay across different regions of the electromagnetic aperture.

21. A vehicle incorporating a control system comprising a radar system incorporating a device for changing the divergence of a beam of electromagnetic radiation, comprising:

a structure having an internal opening that extends through the structure, and an electromagnetic aperture through which the beam passes; and

magnetic means extending through the internal opening in the structure, for controlling a width of the beam by generating a magnetic gradient across the electromagnetic aperture and producing a differential phase delay across different regions of the electromagnetic aperture.

22. The vehicle according to claim 21, wherein the vehicle is a land vehicle.

23. The vehicle according to claim 21, wherein the vehicle is waterborne.

24. The vehicle according to claim 21, wherein the vehicle is airborne.