Cylindrical monopulse

• US 6,195,035 B1
• Filed: 10/12/1984
• Issued: 02/27/2001
• Est. Priority Date: 10/12/1984
• Status: Expired due to Term

• Current Assignee: Textron IPMP L.P
• Original Assignee: Textron Systems Corporation (Textron Inc)
• Inventors: Wood, Joseph R.
• Primary Examiner(s): Sotomayor, John B.
• Application Number:
  US06/660,199
• Time in Patent Office: 5,982 Days
• Field of Search: 343/76, 343/16 M, 343/700 MS, 343/729, 343/908, 343/777, 342/67, 342/153, 342/62, 342/80, 342/90, 342/96, 342/97, 342/149, 342/151, 342/152, 342/194
• US Class Current: 342/80
• CPC Class Codes: G01S 13/4409 HF sub-systems particularly adapted therefor, e.g. circuits for signal combination multi-lobing aerials or aerial systems H01Q25/00
• CPC Class Codes: G01S 13/4445 amplitude comparisons monopulse, i.e. comparing the echo signals received by an antenna arrangement with overlapping squinted beams
• CPC Class Codes: G01S 13/86 Combinations of radar systems with non-radar systems, e.g. sonar, direction finder
• CPC Class Codes: G01S 7/032 Constructional details for solid-state radar subsystems
• CPC Class Codes: G01S 7/034 Duplexers switching devices for waveguides H01P1/10; transmit-receive switching in transceivers H04B1/44
• 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 21/29 Combinations of different interacting antenna units for giving a desired directional characteristic H01Q25/00 takes precedence
• CPC Class Codes: H01Q 25/02 providing sum and difference patterns H01Q25/04 takes precedence

Abstract

A monopulse antenna system comprising an inner antenna and an outer antenna disposed symmetrically about a central axis of symmetry. A central aperture is located at the axis of symmetry through which a weapon system may fire or an additional sensor may be located. The inner antenna is preferably annular in shape and produces a relatively broad antenna pattern. The outer antenna is also preferably annular and produces a beam pattern with many lobes. The received signals A and B, from each beam pattern, are combined in a hybrid to produce sum signals (A+B) and difference signals (A−B), which are then processed to produce a target off-axis radius relative to the antenna main beam axis, i.e., the axis of symmetry.

Claims

1. A monopulse radar system comprising:

a) an inner antenna and

b) an outer antenna

c) each antenna being symmetrically disposed about a line of symmetry extending through the center of said inner antenna;

d) said inner and outer antennas adapted to receive respective signals A and B from targets which are off the line of symmetry, said inner antenna further having a central opening at the line of symmetry;

e) hybrid means coupled to said antennas for providing sum and difference signals from said received signals;

f) means for determining the target angle off the line of symmetry from said sum and difference signals; and

g) a weapon system is positioned on one side of the opening in the inner antenna along the line of symmetry.

2. The system of claim 1 in which a transmitter is coupled to said hybrid means, said transmitter generating a sum signal which is divided in said hybrid to an A signal which is coupled to said outer antenna and a B signal which is coupled to said inner antenna.

3. The system of claim 1 in which the antennas are circular in shape.

4. The system of claim 1 in which the antennas are circular in shape.

5. A monopulse radar system comprising:

a) an inner antenna and

b) an outer antenna

c) each antenna being symmetrically disposed about a line of symmetry extending through the center of said inner antenna;

d) a transmitter means for generating a train of CW pulses which are simultaneously coupled to said inner and outer antenna and radiated therefrom;

e) said inner and outer antennas adapted to receive respective return signals A and B reflected from targets which are off the line of symmetry, said inner antenna further having a central opening at the line of symmetry;

f) hybrid means coupled to said antennas for providing sum and difference signals from said received signals;

g) receiver means for determining the angle of the target off the line of symmetry from said sum and difference signals; and

h) a weapon system is positioned on one side of the opening in the inner antenna along the line of symmetry.

6. The radar of claim 5 further including means in said receiver for modulating the difference signal with a sinusoidal scanning frequency signal to produce a suppressed carrier amplitude modulated signal with an alternating phase at the half cycles of the scan frequency signal.

7. The radar of claim 5 further including in said receiver range gating means for selecting for further processing certain return signals located within a predetermined range from the antennas.

8. The antenna system of claim 5 wherein the inner and outer antennas comprise a plurality of radiating elements.

9. The antenna system of claim 5 wherein the antenna radiating elements are formed in four quadrants per inner and outer antenna which are coupled at one point per antenna.

10. The antenna system of claim 5 wherein the antennas are coupled to an RF power transmitter and to a receiver.

11. The system of claim 10 wherein RF power from the transmitter is propagated through space to the receiver.

12. The system of claim 10 wherein the receiver is a homodyne receiver.