JPS5926085A - Radar device - Google Patents

Abstract

PURPOSE:To shorten a search and an acquisition time by detecting a target by using the wide beam of a phased array antenna, and then directing the narrow beam in the target direction indicated by the output ratio of a sum and a difference channel receiver and performing monopulse tracking. CONSTITUTION:A high-frequency pulse signal generated by a transmitter 6 is radiated into the external air through a transmission/reception switch 7 and the phased array antenna 8. The received signal SIGMA of the sum channel of the antenna 8, on the other hand, is inputted to a sum channel receiver 9 through the switch 7 and its output is supplied to a signal processor 10 and a divider 11. The received signal DELTA of the difference channel of the antenna 8 is inputted to a difference channel receiver 12, whose output is supplied to the divider 11. The output of the divider 11 is inputted to the processor 10. The processor 10 scans the wide beam on the antenna 8 through a beam scanning controller 15 and switched to the narrow beam after the target is detected to perform the monopulse tracking in the target direction based upon the output signal of the divider 11. Thus, the search time and the acquistion time are shortened.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention forms an antenna beam with a wide beam width and an antenna beam with a narrow beam width by controlling a large number of antenna elements forming a phased array antenna. MMek is a radar device that automatically captures and tracks targets using a monopulse phased array antenna. Relating to a radar device that aims to shorten the grafting time and acquisition time of a target by scanning function, beam shape switching function, and target angular error detection function possessed by monopulse tracking radar. It is.

First, a method for acquiring and tracking a target in this type of radar device using a conventional mechanically driven monopulse antenna will be explained using diagrams.

FIG. 1 is a diagram showing an antenna scanning method in a conventional radar device of this type.

During a search, a pencil beam with a narrow antenna beam width of θB is used (11 = search area + 21
Antenna scanning pattern during search that covers all of +31
The entire antenna scan is performed along the . Now, the antenna is at azimuth θ
When a target is detected by scanning the vicinity of the target direction (4) with n and elevation angle θBL, the area where the existence of the target is probabilistically predicted (
Hereinafter, this will be referred to as the "target existence area." ) Antenna scanning is performed along the antenna scanning pattern (5) at the time of acquisition, which is memorized, and the process shifts to monopulse tracking. Therefore, in order to acquire the target and shift to monopulse tracking, it is necessary to increase the search time for scanning with a narrow pencil beam (1) having a width of 21 mm; After detecting the target, an acquisition time is required to scan the target area with the pencil beam fil.

By the way, in a tracking radar, it is essential to shorten the search time and acquisition time mentioned above in order to quickly capture all targets. However, it would be possible to further narrow the target area by increasing the target indication degree during the search.

In this type of radar system using a conventional mechanically driven monopulse antenna, the hardware required to switch the shape of the antenna beam becomes more complex, and target detection and antenna scanning become independent. Therefore, there is usually a drawback that the target presence/head position cannot be narrowed down to about 2 to 4 times the antenna beam width at the time of search.

This invention aims to improve the following two or more drawbacks.
By controlling the large number of antenna elements 'i 0N10FF that make up the entire phased array antenna, a wide beam antenna beam (hereinafter referred to as "first antenna beam") is created to quickly traverse a predetermined search area. It is called.

) and a monopulse type azed array that has the function of forming a narrow beam width antenna beam (hereinafter referred to as the "second antenna beam") for tracking.
When a target is detected during a search using the first antenna beam, the second antenna beam is scanned in the direction of the target obtained using the monopulse principle. It is an object of the present invention to provide a radar apparatus which aims to shorten the search time and acquisition time by shifting to monopulse tracking with omnidirectional antenna beams.

Here, by limiting the number of antenna elements constituting the 2-aided array antenna to 0N10FF,
The function of shaping the first antenna beam and the second antenna beam will be briefly described.

Assuming that the phased play antenna is a circular aperture antenna with an effective diameter of 600 mm and one frequency of 59.5 GH, the beam width of the second antenna beam is approximately 3.
．． 5 degrees, the antenna gain at this time is approximately 33 dB.

Now, in this phased array antenna, if the effective diameter of the antenna is set to about 220 mm by turning off the antenna element located on the outer periphery, the beam width of the first antenna beam will expand to about 10 degrees. , the antenna gain at this time is approximately 24 dB. As described above, by distributing the antenna element '1ON10FF1', it is possible to make the antenna beam oscillate to '=4'. Also, by widening the antenna beam 1, the antenna gain decreases.

Since rapid acquisition and tracking are generally performed for short-range targets, the deterioration in radar range performance caused by this level of antenna gain reduction is not a problem.

Hereinafter, this invention will be explained in detail using FIG. 2 and FIG. 3.

FIG. 2 is a block diagram showing an embodiment of the present invention, and FIG. 3 is a diagram showing the antenna beam scanning method of the present invention. In Figures 2 and 3.

The high frequency pulse signal generated by the transmitter [61] is sent to the transmitting/receiving 9J converter (7) and phased array antenna
radiates into the external space through the

On the other hand, the received signal Σ on the sum channel of the phased array antenna (8) is input to the sum channel receiver [91K] via the transmitter/receiver switch (7), is amplified, and is sent to the signal processor (10) and the divider. is input into the device Uυ. The received signal Δ on the difference channel of the phased array antenna (81) is input to the difference channel receiver (121).

It is amplified and input to the divider (11). divider ul)
calculates the ratio of the output of the sum channel receiver (9) and the output of the difference channel receiver (9) and inputs it to the signal processor (llil).The received signal Δ of the difference channel has azimuth angle and height It is assumed that the angle signal is included in a time-division manner.

Now, when the radar device (13) of the present invention is in a search state, the signal processor α0) processes the output signal of the sum channel receiver (9) and determines that there is no target;
0N10FF 11 Commands the JJI unit u4I and the beam scanning controller (15) to continue the search state. At this time, the 0N10FF controller axis is set to the predetermined antenna element i.
The first antenna beam (16) 'e has a beam width OB1 obtained by turning OFF so that it is continuously shaped.

Also, the beam scanning control enclosure (I5) sets the beam directivity angle to 0.
8 to change the phased array antenna (
8) Full control. By repeating this operation and C, the first antenna beam (I6) is converted to 'J?'. :'+iM
area (beam scanning pattern 0'l that covers all 21)
Beam scanning is performed along the

Now, the lth antenna beam (16) has an azimuth of 08A.
and height angle θswk, the signal processor (IUi
The output signal of the receiver (9) of the sum channel is completely processed and detected, and the output signal of the divider 01 at that time is used to calculate the target angle error ΔO and Δθ according to the monopulse principle.
When EL is detected, 0N10F'F controller C14
1 and beam scanning controller 05) in the acquisition state (
Commands to perform dtl. This directive is 0
The N10FF controller 041 turns on all the antenna elements so that the beam shape can be cut into the second antenna beam (181) with a beam width of θB2.The beam scanning controller (15) The target direction (4
), the second aided play antenna f8+ is fully controlled so as to direct the second antenna beam a'a+w to monopulse tracking.

As described above, according to the present invention, when a target is detected by searching with the first antenna beam having a wide beam width, a tracking beam is set in the target direction given by the beam directivity angle and the angular error of the target at that time. Target search and acquisition time can be reduced by directing the second antenna beam with a narrow beam width.

As an embodiment of this invention, a configuration example is shown in FIG. 2, and a configuration example in FIG.
The figure shows the antenna beam scanning method.

Various modifications may be made without departing from the spirit of the invention.

[Brief explanation of the drawing]

Fig. 1 is a diagram showing an antenna scanning method in a conventional radar device, Fig. 2 is a block diagram showing an embodiment of the present invention, and Fig. 3 is a diagram showing an antenna beam scanning method of the present invention. In the figure, (11 is the Vensil beam, (21 is the projection area, (31 is the antenna scanning pattern during search, (
4) is the target direction, (51 is the antenna scanning pattern of 11 acquisitions, (61 is the transmitter, (71 is the transmitter/receiver switch, (8 is
1 is a phased array antenna, (131 is an O-day channel receiver, (kawa) is a (G-processor,
l&i harm 1 calculator, 0Z is the receiver of the running channel, 03j
is the radar device of this invention, and the circle is 0N10FF・fil
1 distributor, 151 is the beam scanning controller, 06) is the first antenna beam, 07) is the beam scanning pattern, (
IIU is the second antenna beam. In Figure 1, the same or corresponding parts are indicated by the same numbers. Agent Kuzu yr Detective - The False Price IX

Claims (1)

[Claims] By controlling a large number of antenna elements i0N10FF constituting a phased array antenna. It uses a monopulse phased array antenna that has the function of shaping a wide antenna beam for quickly scanning a predetermined search area and a narrow antenna beam for full tracking. , in a radar device configured to automatically capture and track a target, perform antenna beam scanning in synchronization with target detection and switch between the wide antenna beam and the narrow antenna beam. The membrane for controlling the antenna element 20N10FF, the receiver provided corresponding to the sum channel and the difference channel of the monopulse type 2 aided array antenna, and the ratio of the output of each of the receivers. Equipped with calculator and all equipment,
When searching for a target using the antenna beam with a wide beam width, the beam shape is automatically switched and the antenna beam with the narrow beam width is directed in the direction of the target given by the output signal of the divider. A radar device characterized by C, which is horizontally bent so as to shift to monopulse tracking.