Radar-filtered projectile

• US 7,079,070 B2
• Filed: 04/15/2002
• Issued: 07/18/2006
• Est. Priority Date: 04/16/2001
• Status: Active Grant

• Current Assignee: Northrop Grumman Systems Corporation (Northrop Grumman Corporation)
• Original Assignee: Alliant Techsystems Incorporated (Northrop Grumman Corporation)
• Inventors: Kongelbeck, Knut, Mendelovicz, Ada
• Primary Examiner(s): Gregory, Bernarr E.
• Application Number:
  US10/215,475
• Publication Number:
  US 20050253017A1
• Time in Patent Office: 1,555 Days
• Field of Search: 244 31- 33, 342 61- 68, 342/175, 342/195, 343/705
• US Class Current: 342/62
• CPC Class Codes: F41G 7/2266 Systems comparing signals received from a base station and reflected from the target
• CPC Class Codes: F41G 7/2286 using radio waves
• CPC Class Codes: G01S 13/003 Bistatic radar systems; Multistatic radar systems
• CPC Class Codes: G01S 13/422 sequential lobing, e.g. conical scan
• CPC Class Codes: G01S 13/883 for missile homing, autodirectors missile guidance systems F41G7/22
• CPC Class Codes: G01S 7/032 Constructional details for solid-state radar subsystems

Abstract

Disclosed is an autonomous radar guidance of an otherwise radar-directed projectile (RDP). The preferred embodiment uses an inexpensive radar receiver with an inexpensive slow wave antenna, placed internally in a gun projectile, and on the surface of the projectile, respectively. The receiver detects the angle and range of the target relative to the body coordinates of the projectile. The radar receiver operates as a bistatic radar apparatus with the primary illumination emanating from the fire control radar directing the fire of the gun. When integrated with an on-board trajectory correcting system, such as divert thrusters of miniature proportions, the projectile autonomously refines its otherwise ballistic trajectory to the target. The trajectory refinements produce improved kills per round, with the potential for reducing the ammunition expended and time-loading on the fire control system and its guns. An alternative embodiment, in addition to receiving the target-reflected fire control emissions, receives and processes the fire control radar emissions directly in order to enhance homing accuracy.

Claims

1. A radar-directed projectile guidance system comprising:

(a) a first slow wave, end-fire antenna;

(b) a noncoherent RF receiver; and

(c) computing means for processing signals from the RF receiver.

2. The radar-directed projectile guidance system as claimed in claim 1 wherein the noncoherent RF receiver is integrated into a single GaAs chip.

3. The radar-directed projectile guidance system as claimed in claim 1 wherein the noncoherent RF receiver is a crystal video receiver.

4. The radar-directed projectile guidance system as claimed in claim 1 further comprising a second slow wave, end-fire antenna.

5. The radar-directed projectile guidance system as claimed in claim 1 further comprising a low noise amplifier preceding said noncoherent RF receiver.

6. The radar-directed projectile guidance system as claimed in claim 1 further comprising a power subsystem.

7. The radar-directed projectile guidance system as claimed in claim 1 wherein the computing means is a microcomputer.

8. The radar-directed projectile guidance system as claimed in claim 7 wherein the microcomputer is a single chip microcomputer.

9. The radar-directed projectile guidance system as claimed in claim 1 wherein the first slow wave, end-fire antenna comprises a dielectric rod comprising a conductor coated by a dielectric.

10. The radar-directed projectile guidance system as claimed in claim 1 wherein the first slow wave, end-fire antenna comprises a corrugated metallic conductor.

11. A radar-directed projectile comprising:

(a) a first slow wave, end-fire antenna;

(b) a noncoherent RF receiver; and

(c) computing means for processing signals from the RF receiver;

(d) a means for trajectory correction; and

(e) a power system.

12. The radar-directed projectile as claimed in claim 11 wherein the means for trajectory correction is a divert mechanism comprised of one or more divert charges.

13. The radar-directed projectile as claimed in claim 11 wherein the means for trajectory correction is comprised of one or more piezoelectrically actuated aerodynamic surfaces.

14. The radar-directed projectile as claimed in claim 11 wherein the noncoherent RF receiver is integrated into a single GaAs chip.

15. The radar-directed projectile as claimed in claim 11 wherein the noncoherent RF receiver is a crystal video receiver.

16. The radar-directed projectile as claimed in claim 11 further comprising a second slow wave, end-fire antenna.

17. The radar-directed projectile as claimed in claim 11 further comprising a low noise amplifier preceding said noncoherent RF receiver.

18. The radar-directed projectile as claimed in claim 11 further comprising a power subsystem.

19. The radar-directed projectile as claimed in claim 11 wherein the computing means is a microcomputer.

20. The radar-directed projectile as claimed in claim 19 wherein the microcomputer is a single chip microcomputer.

21. The radar-directed projectile as claimed in claim 11 wherein the first slow wave, end-fire antenna comprises a dielectric rod comprising a conductor coated by a dielectric.

22. The radar-directed projectile as claimed in claim 11 wherein the first slow wave, end-fire antenna comprises a corrugated metallic conductor.

23. A projectile comprising:

a guidance system wherein the guidance systems comprises;

at least one end-fire antenna, wherein each of the at least one end-fire antenna comprises a radio frequency (RF) slow wave structure;

an RF receiver operably connected to each of the at least one end-fire antenna; and

an RF receiver signal processor for processing signals received via the RF receiver.

24. The projectile of claim 23 further comprising:

a trajectory correction system operably responsive to one or more output signals from the RF receiver signal processor.

25. The projectile of claim 23 further comprising a power system.