JPH08220213A - Search radar device - Google Patents

Abstract

(57) [Summary] [Object] To provide a long-range search radar device capable of searching the entire circumference with a relatively inexpensive structure. In the search radar device according to the present invention, two antennas 11A and 11B are arranged on the same rotary base 13, and the rotary bases 13 are rotated while being rotated while being oriented in different directions. By searching for a long distance, it is possible to avoid the long-range search and the restriction of the data rate (rotation period of the antenna).

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a search radar device which is mainly installed on the ground and monitors the entire circumference.

[0002]

2. Description of the Related Art As a conventional search radar device, a type in which a reflector is rotated to monitor the entire circumference is mainly used. However, in this type, when a long-range radar is attempted, a reflected signal arrives. Since it takes a long time to perform, it is necessary to reduce the rotation speed.

However, if the number of revolutions is slowed down, the time required for one revolution becomes long, so that the time interval for receiving a signal from the same target (same azimuth) becomes large, and the response delay of the monitoring system and automation of tracking cannot be performed. For this reason, radars of the type described above that rotate a reflector are used only up to medium-range radar.

On the other hand, a type of radar called a phased array is mainly used for long-range radar because it can freely control the transmission direction. However,
The phased array system is complicated and expensive as a radar, and it is necessary to arrange three to four phased arrays to search the entire circumference, which inevitably results in an extremely expensive system.

Under these circumstances, there is a device in which the transmission elevation angle is controlled by a phased array and the azimuth direction is controlled by mechanical rotation to reduce the cost. However, this method cannot avoid the above-mentioned drawbacks, and can fix the antenna around a specific azimuth and search only a long distance for a limited angular range.

[0006]

As described above, in the conventional long-distance search radar device, the use of the phased array is unavoidable, and the system becomes complicated and expensive.

The present invention has been made to solve the above problems, and an object thereof is to provide a long-range search radar device capable of searching the entire circumference with a relatively inexpensive structure.

[0008]

In order to achieve the above object, the present invention has a rotary drive mechanism for mechanically rotating in a horizontal plane, and by the above rotation, a search radar capable of searching for a target in all circumferential directions. In the device, while simultaneously performing a search by transmitting pulses of the same time width to a plurality of azimuth directions, each azimuth to be transmitted continuously changes in accordance with the rotation of the rotary drive mechanism, and the entire circumference is sequentially It is characterized by having been searched.

[0009]

In the search radar apparatus having the above-mentioned structure, a plurality of antennas are arranged on the same rotary drive mechanism, and the rotary drive mechanisms are rotated to rotate the antennas with their directing directions being different from each other. By searching, long range search and data rate (antenna rotation period)
I try to escape from the restrictions.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below with reference to FIG.

FIG. 1 shows the structure of an antenna system which is a feature of the long-distance search radar apparatus according to the present invention.
A and 11B are reflector type antennas having the same performance. Both of these antennas 11A and 11B are mounted back to back on the column 12. The column 12 is mounted on the rotary shaft of a rotary table 13 which is rotated at a constant speed in a horizontal plane by a rotary drive mechanism (not shown).

Each of the antennas 11A and 11B has a structure in which a sub-reflector 112 is arranged in front of the main reflector 111 oriented in the horizontal direction, and a primary radiator 113 is arranged in the central portion of the main reflector 111. Send and receive in different directions.

On the upper portion of the column 12, for example, SLC
(Side Canceller) Antenna and IFF (Identification of Friend or For)
Auxiliary antenna 14 such as an SLS (side lobe suppression) antenna for use in the vehicle is attached.

Although not shown in detail, each antenna 11
The signal processing systems of A, 11B, and 14 are independent of each other, and the video signals obtained individually are linked as necessary.

The operation of the above arrangement will be described below.

Two antennas 11A and 11B are arranged back to back on the same turntable 13 that rotates in a horizontal plane,
Transmission is performed in a direction different by 180 degrees. That is, the antennas 11A and 11B are rotated by the rotary drive of the turntable 13 while being oriented in directions different from each other by 180 degrees, and searched for a long distance.

With this operation, the two antennas 11A and 11B sequentially search for signals in the same direction, so that signals can be obtained at time intervals of half the rotation cycle. On the contrary, if the time interval is fixed, the rotation speed may be half that of the conventional one. Therefore, it is possible to easily allocate the time for long-distance search.

As described above, by disposing the two antennas on the same rotary driving mechanism, it is possible to avoid the long-distance search and the restriction of the data rate (rotation period of the antenna) which cannot be realized conventionally.

Two antennas 11A having the same performance,
In order to further exhibit the characteristics of the radar system having 11B, the following can be realized by adopting the configuration shown in the embodiment.

First, by changing the two transmission frequencies, not only the passive effect of avoiding the interference of signals of each other, but also by compensating the blind of MTI with each other and improving the accuracy of the measurement (frequency diversity effect) It can be folded as a system.

Secondly, since the two antennas 11A and 11B can be regarded as a redundant structure, the reliability is dramatically improved.

Third, an SLC (side-vein canceller) antenna and an IFF (identification
Auxiliary antenna 14 such as SLS (sidelobe suppression) antenna for Of Friend or Fore
If only one is required in common, the minimum configuration can be obtained by arranging it on the upper part of the central column 12 as shown in the figure.

Fourthly, in the case of the Cassegrain type in which the reflectors 111 and 112 are combined with each other, the weight is concentrated in the center, which can be expected to suppress the rotational torque.

Fifth, a one-dimensional phased array in which the sub-reflector 112 is provided with a monitor antenna for performing at least one of transmission / reception state monitoring or antenna elements are arranged in a direction perpendicular to a horizontal plane. A combination with a reflector antenna using the antenna as the primary radiator 113 is also possible.

Therefore, the search radar apparatus equipped with the antenna system having the above-described structure can achieve both the data rate and the long-distance search in an inexpensive structure.

In the above embodiment, the two antennas are arranged on the rotary table 13, but the number of antennas is not limited to two. For example, in the case of three antennas, the respective antennas may transmit and receive signals in directions different by 120 degrees.

Various modifications such as arranging a plurality of phased array antennas on the same drive mechanism are also conceivable.

[0028]

As described above, according to the present invention, it is possible to provide a long-distance search radar device capable of searching the entire circumference with a relatively inexpensive structure.

[Brief description of drawings]

FIG. 1 is an external perspective view showing the configuration of an antenna system that is a characteristic part of an embodiment of a search radar device according to the present invention.

[Explanation of symbols]

 11A, 11B ... Antenna 111 ... Main reflector 112 ... Sub-reflector 113 ... Primary radiator 12 ... Pillar 13 ... Rotating table

Claims (9)

[Claims] 1. A search radar apparatus having a rotary drive mechanism for mechanically rotating in a horizontal plane and capable of searching for a target in all circumferential directions by the rotation, wherein the same time width is simultaneously applied to a plurality of azimuth directions. The search radar device is characterized in that while performing the search by transmitting the pulse of 1, the direction to be transmitted continuously changes in accordance with the rotation of the rotary drive mechanism to sequentially search the entire circumference. 2. A plurality of antennas of the same shape are arranged back to back on one rotary drive mechanism, and searching is simultaneously performed in different azimuths by an angle obtained by dividing the entire circumference by the number of antennas. Item 2. The search radar device according to item 1. 3. The antenna according to claim 2, wherein each of the plurality of antennas is composed of a combination of two kinds of main and sub-reflectors, and a primary radiator is arranged on a side close to a rotation axis. Search radar device. 4. The search radar apparatus according to claim 3, wherein a monitor antenna for performing at least one of a transmission state monitoring and a reception state monitoring is attached to the sub reflector. 5. The pulse to be simultaneously transmitted in the plurality of different azimuth directions has different center frequencies, bandwidths, modulated signals, polarized waves, or combinations thereof. Search radar device. 6. The search radar device according to claim 2, wherein the plurality of antennas transmit pulses having frequencies slightly different from each other. 7. The search radar device according to claim 6, wherein the frequencies of the pulses transmitted from the plurality of antennas are switched at the same time according to the elevation angle and the search distance of the transmission. 8. The search radar apparatus according to claim 6, wherein the frequency of the transmission pulse is changed in the azimuths set for each rotation cycle. 9. The search radar according to claim 2, wherein an auxiliary antenna for the purpose of monitoring the use of radio waves and removing an interfering signal is arranged between the plurality of antennas so as to be shared with each other. apparatus.