JPH06242215A - Radar apparatus - Google Patents

Abstract

PURPOSE:To restrict clutters in the direction of a side lobe with a simple and inexpensive mechanism by adding the random change of the phase to the beam scanning phase in synchronization with a transmission timing signal. CONSTITUTION:A random phase generating part 3b generates the random changing amount of the phase synchronously with a transmission timing signal and sends the amount to a controlling part 3a. The controlling part 3a adds the random changing amount to the beam operating phase, and transfers the phase data in a time sharing manner to each module within a main antenna 1a. When the beam operating phase is set in each module, an antenna pattern of the same main beam wherein only the level of the side lobe is changed is obtained. Therefore, the antenna pattern changes every transmission pulse and the reflection level due to the clutter from the direction of the side lobe is changed. As a result, even when the digital video signals received by the antenna 1a are integrated, the clutter from the direction of the side lobe is not accumulated, thereby preventing that the clutter is detected with all the processing timing of signals.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention utilizes the feature that the antenna pattern can be changed in a time division manner by changing the beam scanning phase of each module of a phased array antenna. The present invention relates to a radar device that suppresses clutter from directions.

[0002]

2. Description of the Related Art FIG. 5 is a diagram showing a conventional radar device, in which 1a is a main antenna which radiates a transmitted wave in a space in a specific direction and receives a reflected wave, and 1b is a guard antenna which receives the reflected wave. Antenna 1 is a phased array antenna composed of the main antenna 1a and the guard antenna 1b, and 2a is a phased array antenna 1 for transmitting a transmission signal of a medium pulse repetition period or a low pulse repetition period. The transmitter 2b is a main channel for converting the reflected signal received by the main antenna 1a of the phased array antenna 1 into a digital video signal, and 2c is received by the guard antenna 1b of the phased array antenna 1. Guard channel for converting the reflected signal to a digital video signal, 2
Is a transmitter / receiver 3a composed of the transmitter 2a, the main channel 2b and the guard channel 2c.
Is a control unit for calculating the beam scanning phase of each module in the phased array antenna 1 and transferring phase data, 3 is a beam controller composed of the control unit 3a,
A signal processor 4 sends a transmission timing signal and a signal processing timing signal to the transceiver 2 and the beam controller 3 and further detects a target from a digital video signal sent from the transceiver 2. The signal processor 4
It is an indicator for displaying target data from.

The operation of the conventional radar device will be described. First, in order to radiate the transmitted wave in the space of a specific direction,
The control unit 3a in the beam controller 3 calculates the beam scanning phase of each module in the phased array antenna 1 and transfers the phase data based on the beam directivity angle data sent from the signal processor 4. . Next, a transmission wave having a medium pulse repetition period or a low pulse repetition period, which is transmitted from the transmitter 2a in the transceiver 2 in synchronization with the transmission timing signal generated by the signal processor 4, is transmitted from the phased array antenna 1 to space. The reflected waves from the target 6 and the ground 7 are emitted as shown in FIG.
The main antenna 1a having the reception pattern of the beam 8 and the side lobe 9 and the guard antenna 1b having the reception pattern of the guard pattern 10 receive. Next, the reflected waves received by these two antennas are sent to the transceiver 2 and converted into digital video signals by the main channel 2b and the guard channel 2c.

The signal processor 4 detects a target from the digital video signal sent from the transceiver 2.
Here, when performing target detection by transmitting a medium pulse repetition period, the signal processor 4 repeats m kinds of pulse repetitions in synchronization with m kinds of signal processing timing signals (FIG. 7B) as shown in FIG. Transmission timing signal with a cycle (Fig. 7
(A)) is generated. Then, in order to suppress the clutter from the side lobe direction by integrating the digital video signals of the main channel 2b and the guard channel 2c obtained within one signal processing timing, the main channel 2b and the guard channel 2c are integrated. The amplitudes of 2c are compared, and the amplitude ratio is compared with that of the main antenna 1a and the guard antenna.
When the value is equal to or larger than the value determined by the gain difference of the antenna 1b, the data is held internally as a temporary target. further,
The above-described processing is performed at every m kinds of signal processing timings, and the target finally detected at the signal processing timing of n / m or more is set as a true target, and the target data is displayed on the display unit 5.

When performing target detection by transmitting a low pulse repetition period, the signal processor 4 synchronizes with one type of signal processing timing signal (FIG. 8 (b)) as shown in FIG. The transmission timing signal (FIG. 8 (a)) having the pulse repetition period of is generated. Then, the main channel 2b and the guard channel 2c are integrated in order to integrate the digital video signals of the main channel 2b and the guard channel 2c obtained within the signal processing timing and suppress clutter from the side lobe direction.
Of the main antenna 1a.
If the value is greater than or equal to the gain difference of the guard antenna 1b, the target data is displayed on the display 5 as a target.

[0006]

In the radar apparatus as described above, in order to suppress clutter in the side lobe direction, the phased array antenna 1 has a main antenna 1a, a guard antenna 1b, and a transceiver. Since 2 requires two receiving channels corresponding to the main antenna 1a and the guard antenna 1b, there is a problem that the hardware becomes complicated and expensive.

Further, the pattern characteristics of the conventional guard antenna 1b are broad downward so as to suppress clutter in the side lobe direction due to reflection from the ground. Therefore, ECM (Electronic)
When the interference wave was radiated from the upper side lobe direction by the Counter Measure machine, the interference wave could not be suppressed.

The present invention has been made to solve the above problems, and it is possible to change the antenna pattern by changing the beam scanning phase set in each module of the phased array antenna. It is an object of the present invention to obtain an apparatus that can suppress clutter from the side lobe direction by forming an antenna pattern in which the main beam is the same and only the side lobe level changes by utilizing the characteristic

It is another object of the present invention to obtain a device capable of improving the target detection performance by utilizing the guard antenna for suppressing the interfering wave by the ECM machine from the upper side lobe direction.

[0010]

In a radar apparatus according to the present invention, a random phase change generated in a beam controller is added to a beam scanning phase in synchronization with a transmission timing signal or a signal processing timing signal. , The phase data is transferred to each module in a time division manner.

Further, the present invention uses a guard antenna having a pattern characteristic that is broad toward the top.

[0012]

In the present invention, the antenna pattern can be changed in a time division manner by changing the beam scanning phase in a time division manner.

Further, according to the present invention, by using a guard antenna having a pattern characteristic that is broad toward the upper side, it is possible to suppress an interfering wave from the ECM machine from the upper side lobe direction.

[0014]

【Example】

Example 1. FIG. 1 is a diagram showing an embodiment of the present invention. Reference numerals 4 and 5 are exactly the same as those of the conventional device. 1a is a main antenna that radiates a transmitted wave in a space in a specific direction and receives a reflected wave, 1 is a phased array antenna configured by the main antenna 1a, and 2a
Is a transmitter for transmitting a transmission signal having a medium pulse repetition period or a low pulse repetition period to the phased array antenna 1 and 2b is a digital signal for the reflection signal received by the main antenna 1a of the phased array antenna 1. Main channel to convert to video signal,
Reference numeral 2 is a transmitter / receiver including the transmitter 2a and the main channel 2b, 3b is a random phase generator for generating a random phase change amount in synchronization with a transmission timing signal or a signal processing timing signal, and 3a is a beam scanning phase. Is added to the random phase change amount generated by the random phase generator 3b in synchronization with the transmission timing signal or the signal processing timing signal, and the phase data is time-divided into each module in the phased array antenna 1. The control unit 3 for transferring to the beam controller is a beam controller including the control unit 3a and the random phase generation unit 3b.

In the radar apparatus configured as described above, the beam scanning phase represented by the following equation is calculated in synchronization with the transmission timing signal in the control unit 3a in the beam controller 3, and the time is calculated for each module. Transferred in divisions. Pn ^' = Pn + Pr ……………… (1)

Here, Pn is a conventional beam scanning phase, Pn
r is the random phase change amount of the average value 0 generated by the random phase generator 3b in the beam controller 3. When such a beam scanning phase Pn ^' is set in each module, an antenna pattern as shown in FIG. 2 is obtained in which the main beam is the same and only the side lobe level changes. Therefore, when the target detection is performed by transmitting the medium pulse repetition period, if the beam scanning phase Pn ^′ is transferred to each module in synchronization with the transmission timing signal, the antenna pattern changes for each transmission pulse and the side The reflection level from the clutter coming from the lobe direction also changes. As a result, clutter from the sidelobe direction does not build up even if the digital video signal received by the main antenna is integrated,
Clutter is not detected at all signal processing timings.

Example 2. In the first embodiment, when the target detection is performed by transmitting the medium pulse repetition period, the beam scanning phase Pn ^′ is transferred to each module in synchronization with the transmission timing signal, and the antenna pattern is changed for each transmission pulse. Although the clutter from the side lobe direction is suppressed by the above, the beam scanning phase Pn ^′ is transferred to each module in synchronization with the signal processing timing signal in the present embodiment, and the antenna pattern is generated at each signal processing timing. It is intended to change the reflection level from the clutter by changing it. As a result, the digital signals received by the main antenna in the m kinds of signal processing timings are received.
Even if the video signal is integrated, the clutter from the side lobe direction does not pile up. The signal processing timing increases, and n /
The clutter from the side lobe direction is not detected at a signal processing timing of m or more, and eventually the clutter is not detected as a true target.

Example 3. In the first embodiment, when the target detection is performed by transmitting the medium pulse repetition period, the beam scanning phase Pn ^′ is transferred to each module in synchronization with the transmission timing signal, and the antenna pattern is changed for each transmission pulse. Although the clutter from the side lobe direction is suppressed by the above, the beam scanning phase Pn ^′ can be transferred to each module in synchronization with the transmission timing signal even when the target detection is performed by the transmission of the low pulse repetition period. For example, clutter from the side lobe direction cannot be detected by the same principle as in the first embodiment.

Example 4. FIG. 3 is a diagram showing an embodiment of the present invention. 1, 2, 4, 5 are exactly the same as the above-mentioned conventional device. Reference numeral 3b denotes a random phase generator for generating a random phase change amount in synchronization with the transmission timing signal or signal processing timing signal, and reference numeral 3a denotes the random phase generator for synchronizing the beam scanning phase with the transmission timing signal or the signal processing timing signal. The controller 3 for adding the random phase change amount generated in 3b and transferring the phase data to each module in the phased array antenna 1 in time division is composed of the controller 3a and the random phase generator 3b. It is a beam controller configured.

Even in the radar apparatus configured as described above, when the target detection is performed by transmitting the medium pulse repetition period, the clutter can be suppressed from the side lobe direction according to the same principle as the first embodiment. Nor. Further, in the present embodiment, the guard antenna 1b, which is conventionally used to suppress the clutter from the side lobe direction, is changed to the one having the broader guard pattern 10 as shown in FIG. By doing
The interference wave 13 from the ECM machine 12 from above is suppressed by comparing the amplitude ratios of the main channel 1a and the guard channel 1b in the same manner as clutter suppression from the side lobe direction in the related art, thereby preventing the occurrence of false alarms. It aims to improve the target detection performance.

Example 5. In the fourth embodiment, when the target detection is performed by transmitting the medium pulse repetition period, the clutter in the side lobe direction is suppressed by the same principle as in the first embodiment, and the guard channel 1b is used in the ECM machine in the side lobe direction. This is used for suppressing the interference wave due to the above, but in the present embodiment, the clutter from the side lobe direction is suppressed by the same principle as that of the second embodiment, and further, the guard antenna 1 is used.
b is used for the same purpose as in the fourth embodiment.

Embodiment 6. In the fourth embodiment, when the target detection is performed by transmitting the medium pulse repetition period, the beam scanning phase Pn ^′ is transferred to each module in synchronization with the transmission timing signal, and the antenna pattern is changed for each transmission pulse. Although the clutter from the side lobe direction is suppressed by this, in the present embodiment, when the target detection is performed by the transmission of the low pulse repetition period, the clutter from the side lobe direction is suppressed by the same principle as in the third embodiment. Further, the guard antenna 1b is used for the same purpose as in the fourth embodiment.

[0023]

Since the present invention is constructed as described above, it has the following effects.

When the target detection is performed by transmitting the medium pulse repetition period, the clutter in the side lobe direction can be suppressed by changing the antenna pattern in synchronization with the transmission timing signal. Therefore, the guard antenna for clutter suppression is used. Since the reception channel for the guard antenna is not required, the hardware can be simple and inexpensive.

Further, when the target is detected by transmitting the medium pulse repetition period, the clutter in the side lobe direction can be suppressed by changing the antenna pattern in synchronization with the signal processing timing signal. Since the guard antenna and the reception channel for the guard antenna are not required, the hardware can be simple and inexpensive.

Further, when the target detection is performed by the transmission of the low pulse repetition period, the clutter in the side lobe direction can be suppressed by changing the antenna pattern in synchronization with the transmission timing signal. -Since the reception channel for the antenna and the guard antenna is not required, the hardware can be simple and inexpensive.

Further, when the target detection is performed by transmitting the medium pulse repetition period, the clutter suppressing effect can be improved by changing the antenna pattern in synchronization with the transmission timing signal. The guard antenna used for the above can be used for suppressing the interfering wave by the ECM machine from the upper side lobe direction, and the target detection performance can be improved.

Further, when the target is detected by transmitting the medium pulse repetition period, the clutter suppressing effect can be improved by changing the antenna pattern in synchronization with the signal processing timing signal, and the clutter suppressing effect can be further improved. The guard antenna used for this purpose can be used for suppressing the interfering wave by the ECM machine from the upper side lobe direction, and the target detection performance can be improved. .

Further, when the target detection is performed by the transmission of the low pulse repetition period, the clutter suppressing effect can be improved by changing the antenna pattern in synchronization with the transmission timing signal. The guard antenna used for the above can be used for suppressing the interfering wave by the ECM machine from the side lobe direction, and the target detection performance can be improved.

[Brief description of drawings]

FIG. 1 is a diagram showing a radar device according to a first embodiment of the present invention.

FIG. 2 is a diagram in which antenna patterns are overwritten when the beam scanning phase is changed.

FIG. 3 is a diagram showing a radar device according to a fourth embodiment of the present invention.

FIG. 4 is a diagram in which a guard antenna is used for suppressing an interfering wave by an ECM machine from above.

FIG. 5 is a diagram showing a conventional radar device.

FIG. 6 is a diagram showing reception patterns of a main antenna and a guard antenna.

FIG. 7 is a diagram showing a transmission timing signal and a signal processing timing signal when a target is detected by transmitting a medium pulse repetition period.

FIG. 8 is a diagram showing a transmission timing signal and a signal processing timing signal in the case of performing target detection by transmitting a low pulse repetition period.

[Explanation of symbols]

 1 Phased Array Antenna 1a Main Antenna 1b Guard Antenna 2 Transceiver 2a Transmitter 2b Main Channel 2c Guard Channel 3 Beam Controller 3a Controller 3b Random Phase Generator 4 Signal Processor 5 Indicator 6 Target Device 7 Ground 8 Main beam 9 Sidelobe 10 Guard pattern 11 Mother machine 12 ECM 13 Interfering wave

Claims (6)

[Claims] 1. A phased array which radiates a transmitted wave in a space of a specific direction and receives a reflected wave by a main antenna.
An antenna, a transmitter / receiver for transmitting a transmission signal with a medium pulse repetition period to the phased array antenna, and a reflected signal received by the phased array antenna to a digital video signal, and the phased
The beam scanning phase of each module in the array antenna is calculated, and the random phase change generated internally in synchronization with the transmission timing signal is added to this beam scanning phase, and the phased array is time-divided.・ Beam controller for transferring to each module in the antenna, sending / receiving the transmitting timing signal and the signal processing timing signal to the transceiver and the beam controller, and further targeting from the digital video signal sent from the transceiver. A radar device comprising: a signal processor for detecting the above-mentioned condition; and a display device for displaying target data sent from the signal processor. 2. A phased array which radiates a transmitted wave in a space of a specific direction and receives a reflected wave by a main antenna.
An antenna, a transmitter / receiver for transmitting a transmission signal with a medium pulse repetition period to the phased array antenna, and a reflected signal received by the phased array antenna to a digital video signal, and the phased
The beam scanning phase of each module in the array antenna is calculated, and the random phase change amount internally generated in synchronization with the signal processing timing signal is added to this beam scanning phase, and the phased A beam controller for transferring to each module in the array antenna, sending a transmission timing signal and a signal processing timing signal to the transceiver and the beam controller, and further from a digital video signal sent from the transceiver. A radar device comprising a signal processor for detecting a target and a display for displaying target data sent from the signal processor. 3. A phased array which radiates a transmitted wave in a space of a specific direction and receives a reflected wave by a main antenna.
An antenna, a transmitter / receiver for transmitting a transmission signal having a low pulse repetition period to the phased array antenna, and converting a reflected signal received by the phased array antenna into a digital video signal, and the phased
The beam scanning phase of each module in the array antenna is calculated, and the random phase change generated internally in synchronization with the transmission timing signal is added to this beam scanning phase, and the phased array is time-divided.・ Beam controller for transferring to each module in the antenna, sending / receiving the transmitting timing signal and the signal processing timing signal to the transceiver and the beam controller, and further targeting from the digital video signal sent from the transceiver. A radar device comprising: a signal processor for detecting the above-mentioned condition; and a display device for displaying target data sent from the signal processor. 4. A phased array antenna that radiates a transmitted wave in a space in a specific direction and receives a reflected wave by a main antenna and a guard antenna, and a transmitted signal with a medium pulse repetition period in the phased array antenna. For transmitting and receiving, and converting the reflected signals received by the main antenna and guard antenna of the phased array antenna into digital video signals, and the beam scanning phase of each module in the phased array antenna. Then, the beam control is performed by adding the random phase change amount internally generated in synchronization with the transmission timing signal to this beam scanning phase and transferring it to each module in the phased array antenna in time division. To the transmitter, the transceiver, and the beam controller. A signal processor for detecting a target from the digital video signal transmitted from the transceiver, and a display for displaying target data transmitted from the signal processor. A characteristic radar device. 5. A phased array antenna that radiates a transmitted wave in a space of a specific direction and receives a reflected wave by a main antenna and a guard antenna, and a transmitted signal with a medium pulse repetition period in the phased array antenna. For transmitting and receiving, and converting the reflected signals received by the main antenna and guard antenna of the phased array antenna into digital video signals, and the beam scanning phase of each module in the phased array antenna. Then, the random phase change amount generated internally in synchronization with the signal processing timing signal is added to this beam scanning phase, and the phased array
Beam controller to transfer to each module in the antenna,
A signal processor for transmitting a transmission timing signal and a signal processing timing signal to the transceiver and the beam controller, and further for detecting a target from a digital video signal transmitted from the transceiver, and the signal processor. A radar device comprising: a display for displaying target data to be transmitted. 6. A phased array antenna that radiates a transmitted wave in a space of a specific direction and receives a reflected wave by a main antenna and a guard antenna, and a transmitted signal with a low pulse repetition period in the phased array antenna. For transmitting and receiving, and converting the reflected signals received by the main antenna and guard antenna of the phased array antenna into digital video signals, and the beam scanning phase of each module in the phased array antenna. Then, the beam control is performed by adding the random phase change amount internally generated in synchronization with the transmission timing signal to this beam scanning phase and transferring it to each module in the phased array antenna in time division. To the transmitter, the transceiver, and the beam controller. A signal processor for detecting a target from the digital video signal transmitted from the transceiver, and a display for displaying target data transmitted from the signal processor. A characteristic radar device.