JP2015184016A - Radar device and method of time-modulating radar device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve the problem of a radar device equipped with a conventional time-modulation array antenna that a frequency range for detecting a target is limited in accordance with the number of amplitude-phase distribution setting means and the repetition frequency of a transmitted or a received signal, thereby making it possible to identify the virtual image of the repetition frequency and the target signal, but presenting a drawback in that the frequency range for detecting the target is narrower than a radar device that does not have the time-modulation array antenna.SOLUTION: A radar device equipped with a time-modulation array antenna according to the present invention is designed to perform time modulation successively within a transmitted pulse signal, and to demodulate a received pulse signal reflected at a target by sampling it at time intervals of sub-pulse signals derived by dividing the transmitted pulse signal into a plurality and integrating the sampled signals. It is thereby made possible, without extending the repetition cycle of modulation, to detect the target in the same frequency range as that of a radar device that does not have the time-modulation array antenna.

Description

  The present invention relates to a radar apparatus that detects a target by changing excitation amplitudes and phases of a plurality of element antennas according to a target frequency and a repetition frequency of a transmission signal or a reception signal. Specifically, the present invention relates to a radar apparatus using a time modulation array antenna that can reduce the side lobe level of the antenna.

Radar devices are required to have low side lobes in order to eliminate the influence of clutter incident from the side lobe region of the antenna. Amplitude control is required to realize a low sidelobe with an antenna, but it is not easy to realize such as an increase in amplitude resolution and amplitude ratio.
Thus, there is a time-modulated array antenna that does not require amplitude control and can realize low side lobe. The time modulation array antenna changes the aperture distribution in a time-sharing manner and realizes low side lobe by time integration.
A radar apparatus using a time-modulated array antenna has a problem that a virtual image is generated due to a long modulation repetition period. As a method for solving this problem, conventionally, a method for identifying a target signal and a virtual image by limiting a frequency range in which a target is detected has been proposed (for example, see Patent Document 1).

Japanese Patent Application No. 2013-049269

In a conventional radar device using a time-modulated array antenna, the virtual image of the aliasing frequency and the target signal are limited by limiting the frequency range in which the target is detected according to the number of amplitude phase distribution setting means, the transmission signal, and the repetition frequency of the reception signal. Can be identified.
On the other hand, the frequency range for detecting a target according to the number of amplitude phase distribution setting means, the repetition frequency of the transmission signal, and the reception signal is narrower than that of a radar device that does not have a time-modulated array antenna, thus reducing the radar performance. There was a problem of making it happen.

Further, in the conventional radar apparatus, the frequency range in which the target is detected is limited even in a situation where the target is facing and approaching, so the frequency region in which the influence of clutter is small (also referred to as clutter-free) in target detection. (See FIG. 12), the radar performance deteriorates.

The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a radar apparatus using a time-modulated array antenna that can detect a target without limiting the frequency range in which the target is detected. .

  A radar apparatus according to the present invention includes a signal generator that generates a timing signal, a transmitter that generates a transmission pulse signal based on the timing signal, and the transmission pulse signal that is output to a power distribution synthesizer. A transmission / reception signal separator that outputs a received pulse signal reflected and received to a receiver, and a power distribution unit that distributes the transmission pulse signal to N transmission pulse signals and outputs the transmission pulse signals to each of the distributed N phase shifters. A combiner; a phase shifter that changes the phase of the transmission pulse signal; an amplitude adjuster that adjusts the amplitude of the transmission pulse signal output from the phase shifter; and the transmission pulse signal output from the amplitude adjuster. An element antenna that radiates to the space, an amplitude phase setting unit that includes a plurality of sets of amplitude phases composed of phases and amplitudes set for the phase shifter and the amplitude adjuster, and the amplitude phase A switching device 8 for switching the amplitude phase set for the phase shifter and the amplitude adjuster in a time division manner in the transmission pulse signal, and a time in the transmission pulse signal. A receiver for receiving a reception pulse signal in which a transmission pulse signal modulated by division is reflected by a target; a demodulator for demodulating the reception pulse signal; and converting the received pulse signal after demodulation to a signal in the frequency domain A frequency conversion device and a target detector for detecting a target signal from the signal converted into the frequency domain are provided.

According to the radar apparatus of the present invention, since time modulation is continuously performed in the transmission pulse signal, the same frequency range as that of the radar apparatus having no time modulation array antenna is obtained without increasing the modulation repetition period. Thus, the target can be detected.
In addition, a demodulator that demodulates a signal that has been subjected to time modulation can also be used as a demodulator that mainly performs demodulation of code modulation in a pulse compression radar. Therefore, it is necessary to newly provide a demodulator dedicated to time modulation. Therefore, a radar apparatus using a time modulation array antenna can be easily provided.

It is a block diagram of the radar apparatus which concerns on Embodiment 1 of this invention. In Embodiment 1 of this invention, it is a partial block diagram in case the number of time modulation is two. It is an aspect figure which shows distribution of the 1st amplitude setting value and distribution of a phase setting value in Embodiment 1 of this invention. It is a mode figure which shows the distribution of the 2nd amplitude setting value in Embodiment 1 of this invention, and distribution of a phase setting value. It is explanatory drawing explaining the transmission pulse signal in Embodiment 1 of this invention. It is explanatory drawing explaining the sampling rate of a demodulator in Embodiment 1 of this invention. It is a figure which shows the characteristic converted into the frequency domain in Embodiment 1 of this invention. It is an aspect figure explaining the aspect of the time modulation at the time of the transmission pulse signal and reception in Embodiment 2 of this invention. It is a block diagram of the radar apparatus which concerns on Embodiment 3 of this invention. It is explanatory drawing explaining the return example of the clutter when the time modulation operation commander in Embodiment 3 of this invention stops time modulation. It is an example when the time modulation operation command device according to the third embodiment of the present invention executes time modulation, and is an explanatory diagram illustrating an example of clutter folding when the number of time modulations is two. It is explanatory drawing explaining a clutter free area | region becoming narrow when a time modulation | alteration array antenna is performed in the conventional radar apparatus.

Embodiment 1 FIG.
A radar apparatus and a time modulation method for the radar apparatus according to Embodiment 1 of the present invention will be described below. 1 to 7 are diagrams for explaining a radar device and a time modulation method of the radar device according to the first embodiment.

FIG. 1 is a configuration diagram of a radar apparatus 100 according to Embodiment 1 of the present invention. 1, a radar apparatus 100 according to Embodiment 1 includes a signal generator 1, a transmitter 2, a transmission / reception signal separator 3, a power distribution synthesizer 4, phase shifters 5-1 to 5-N, Amplitude adjusters 6-1 to 6-N, element antennas 7-1 to 7-N, switch 8, and first amplitude phase setting device to Nth amplitude phase setting device 9-1 to 9-N And an arithmetic unit 10, a receiver 14, a demodulator 15, a frequency converter 16, and a target detector 17.
The radar apparatus 100 according to the first embodiment is characterized in that a demodulator 15 is provided between the receiver 14 and the frequency conversion apparatus 16.

Next, the signal flow of the radar apparatus according to the first embodiment will be described.
Here, the transmission will be described first.
First, the signal generator 1 generates a timing signal necessary for the transmission pulse and outputs it to the transmitter 2.
The transmitter 2 generates a transmission pulse signal according to the timing signal and outputs the transmission pulse signal to the transmission / reception signal separator 3.
The first transmission / reception signal separator 3 outputs the transmission pulse signal to the power distribution synthesizer 4.
The power distribution synthesizer 4 distributes the transmission pulse signal into N transmission pulse signals and outputs the transmission pulse signals to N phase shifters 5-1 to 5-N, and then the N phase shifters. Transmission pulse signals are output to N amplitude adjusters 6-1 to 6-N connected to 5-1 to 5-N.
Further, the N transmission pulse signals are output to the space from the element antennas 7-1 to 7-N via the N amplitude adjusters 6-1 to 6-N.

Here, a time modulation method for a transmission pulse signal will be described with reference to FIGS. The means of the time modulation array antenna switches the phase shift set values of the phase shifters 5-1 to 5-N and the amplitude adjustment set values of the amplitude adjusters 6-1 to 6-N in time, A transmission pulse signal transmitted from 7-1 to 7-N to space is modulated. Actually, in addition to the phase shift set value, the beam scan phase set value is added to the phase shifters 5-1 to 5 -N.

  The number of time modulations is determined by the number of first amplitude phase setting devices to Mth amplitude phase setting devices 9-1 to 9-M in FIG.

FIG. 2 is a block diagram showing a part of the radar apparatus 100 when the number of time modulations is two. The switch 8, the first amplitude phase setting apparatus 9-1, and the second amplitude phase setting apparatus 9- 2 and the arithmetic unit 10 are shown.
FIG. 3 is a diagram showing the distribution of the first amplitude setting value and the distribution of the phase setting value.
FIG. 4 is an aspect diagram showing the distribution of the second amplitude setting value and the distribution of the phase setting value.
For example, when the number of element antennas is N = 4 and the number of time modulations is M = 2, as shown in FIG. 2, two of the first amplitude phase setting device 9-1 and the second amplitude phase setting device 9-2 are used. There are provided two amplitude phase setting devices, a first set combining the amplitude set value distribution 18-1 and the phase set value distribution 19-1 shown in FIG. 3, and the amplitude set value distribution 18-2 shown in FIG. And the second set obtained by combining the distributions 19-2 of the phase setting values are calculated by the calculation device 10 and are held in the first amplitude phase setting device 9-1 and the second amplitude phase setting device 9-2, respectively.

The amplitude set value distribution 18-1 shown in FIG. 3 and the amplitude set value distribution 18-2 shown in FIG. 4 indicate the intensity of the transmission pulse signal radiated from the element antennas 7-1 to 7-4. is there. The intensity of the transmission pulse signal radiated from the element antennas 7-1 to 7-4 is realized by the amplitude adjusters 6-1 to 6-4 shown in FIG.
On the other hand, the phase setting value distribution 19-1 shown in FIG. 3 and the phase setting value distribution 19-2 shown in FIG. 4 indicate the phases of the transmission pulse signals radiated from the element antennas 7-1 to 7-4. The phase shift of the transmission pulse signal radiated from the element antennas 7-1 to 7-4 is realized by the phase shifters 5-1 to 5-4 shown in FIG.

  Next, a first set (see FIG. 3) in which the amplitude set value distribution 18-1 and the phase set value distribution 19-1 held in the first amplitude phase setting device 19-1 are combined, and the second The second set (see FIG. 4) in which the amplitude setting value distribution 18-2 and the phase setting value distribution 19-2 held in the amplitude phase setting device 19-2 are switched by the switch 8, The timing when the amplitude phase set values are transmitted to the phase shifters 5-1 to 5-4 and the amplitude adjusters 6-1 to 6-4 will be described with reference to FIG.

  FIG. 5 is a diagram illustrating an aspect of a transmission pulse signal of the radar apparatus in the transmission according to the first embodiment. In FIG. 5, 11 is the pulse repetition period (PRI) of the transmission pulse signal, 12 is the amplitude phase setting value of the first amplitude phase setting device set in the amplitude adjuster and the phase shifter, and radiated from the element antenna 13 is a transmission pulse signal when the amplitude phase setting value of the second amplitude phase setting device is set in the amplitude adjuster and the phase shifter and is radiated from the element antenna, and 20 is a receivable time range. It is.

  As shown in FIG. 5, the amplitude phase setting values of the first amplitude phase setting device 9-1 are set in the amplitude adjusters 6-1 to 6-4 and the phase shifters 5-1 to 5-4. The transmission pulse signal 12 when radiated and the amplitude phase setting value of the second amplitude phase setting device 9-1 are set in the amplitude adjusters 6-1 to 6-4 and the phase shifters 5-1 to 5-4. Then, the transmission pulse signal 13 when radiated from the element antenna is continuously radiated from the element antennas 7-1 to 7-4 to the space within one transmission pulse signal.

  The transmission pulse signal radiated to the space is reflected by the target, returns to the element antennas 7-1 to 7-4 again, and is received as a reception pulse signal in the receivable time range 20.

After that, the amplitude adjusters 6-1 to 6-N (N = 4 in the first embodiment), the phase shifters 5-1 to 5-N (N = 4 in the first embodiment) and the power distribution and combination in FIG. The signal is input to the receiver 14 from the transmission / reception signal separator 3 via the receiver 4.

At this time, the phase shifters 5-1 to 5-N (N = 4 in the first embodiment) and the amplitude adjusters 6-1 to 6-N (N = 4 in the first embodiment) at the time of reception are An amplitude phase setting value corresponding to the time modulation from the switch 8 is not necessary, and a time phase fixed amplitude phase setting value is set.
Note that a beam scanning phase setting value is set as the fixed amplitude phase setting value set in the phase shifters 5-1 to 5-N (N = 4 in the first embodiment).

The received pulse signal input to the receiver 14 is input to the demodulator 15.
The demodulator 15 is a demodulator mainly responsible for the demodulation of the code modulation in the pulse compression radar as shown in FIG. Do.

  In the demodulator 15, the amplitude phase setting values are set in the amplitude adjusters 6-1 to 6 -N and the phase shifters 5-1 to 5 -N by the first amplitude phase setting device 9-1, and are radiated from the element antenna. The received pulse signal from which the transmitted pulse 12 is reflected by the target, and the amplitude phase setting values by the second amplitude phase setting device 9.2 are amplitude adjusters 6-1 to 6-N and phase shifters 5-1 to 5-1. The reception pulse signal which is set to 5-N and the transmission pulse 13 radiated from the element antenna is reflected at the target is sampled and integrated at intervals of the sub-pulse signal 30. In this manner, the demodulator 15 demodulates the received pulse signal necessary as a radar signal from the two received pulse signals modulated in time.

  At this time, the demodulator 15 has a performance capable of sampling at intervals of the sub-pulse signal 30 (sub-pulse width 30t) obtained by dividing the transmission pulse signal shown in FIG. A transmission pulse 12 to be modulated (a transmission pulse 12 radiated from the element antenna with the amplitude phase setting value set in the amplitude adjuster and the phase shifter by the first amplitude phase setting device 9-1) and the transmission pulse 13 (second Sampling the transmission pulse 13) radiated from the element antenna with the amplitude phase setting value set in the amplitude adjuster and the phase shifter by the amplitude phase setting device 9-2 is not a special problem and can be easily performed.

Next, the received pulse signal sampled and integrated by the demodulator 15 is input to the frequency converter 16.
The frequency converter 16 converts the received pulse signal input from the demodulator 15 into a frequency domain signal.
The target detector 17 detects a target signal from the converted frequency domain signal.

FIG. 7 is a diagram showing characteristics after the received pulse signal from the demodulator 15 is converted into a frequency domain signal in the frequency converter 16. In FIG. 7, 22 is a target signal, and 21 is a virtual image signal of clutter folding generated at a frequency that is the inverse of the pulse repetition period (PRI) 11 of the transmission pulse signal (FIG. 5).

The clutter folding virtual image 21 having the longest repetition period in the first embodiment and the clutter folding virtual image signal 21 generated at a frequency that is the inverse of the pulse repetition period (PRI) 11 of the transmission pulse signal (see FIG. 5) are: , The same cycle. For this reason, as shown in FIG. 7, the clutter-turned virtual image signal overlaps the clutter-turned virtual image signal 21 generated at a frequency that is the inverse of the pulse repetition period (PRI) 11 of the transmission pulse signal.

As described above, the radar apparatus according to the present embodiment includes the demodulator 15 between the receiver 14 and the frequency converter 16, and the demodulator 15 has the amplitude by the first amplitude phase setting apparatus 9-1. A reception pulse signal in which a transmission pulse 12 radiated in space with a phase setting value set is reflected by a target, and a transmission pulse in which an amplitude phase setting value is set by the second amplitude phase setting device 9-2 and radiated into space The reception pulse signal 13 reflected by the target 13 is sampled and integrated at the time interval of the sub-pulse signal 30 obtained by dividing the transmission pulse signal into a plurality. In this way, the demodulator 15 demodulates the received pulse signal necessary as a radar signal from the two received pulse signals modulated in time.
The radar apparatus according to the present embodiment solves the problem that the frequency range for target detection becomes narrow and the radar performance deteriorates, which has been a problem in a radar apparatus using a conventional time-modulated array antenna. It is possible to detect the target without limiting the area.

Embodiment 2. FIG.
In the radar apparatus according to the first embodiment, time modulation is performed at the time of transmission. In the second embodiment, time modulation is performed at the time of reception.

The configuration of the radar apparatus according to the second embodiment is the same as that of the radar apparatus described in the first embodiment, as shown in FIG.
FIG. 8 is a diagram showing the relationship between the transmission pulse signal of the radar apparatus according to Embodiment 2 and time modulation during reception. In FIG. 8, 22 is a transmission pulse signal that is not time-modulated, 23 is a first modulation of time modulation at the time of reception, and 24 is a second modulation of time modulation at the time of reception. In the present embodiment, the number of time modulations at the time of reception is described as two. However, the number of time modulations is not limited to two and may be two or more.

Next, the operation will be described.
In FIG. 8, unlike the first embodiment, the radar apparatus according to the second embodiment does not perform time modulation during transmission. For this reason, the transmission pulse signal 22 which is not time-modulated is radiated into the space from the element antennas 7-1 to 7-N (see FIG. 1).

  The non-time-modulated transmission pulse signal 22 radiated to the space is reflected by the target, is returned to the element antennas 7-1 to 7-N again, and is time-modulated at the time of reception.

Here, a method of time modulation at the time of reception in the radar apparatus according to Embodiment 2 will be described.
This is a modulation method for performing time modulation at the time of reception. The phase shift set values of the phase shifters 5-1 to 5-N and the amplitude adjustment set values of the amplitude adjusters 6-1 to 6-N in FIG. Since the switching is the same as the time modulation at the time of transmission described in the first embodiment, the description is omitted.
Here, in the time modulation at the time of reception, the timing when the amplitude phase set value is transmitted to the phase shifters 5-1 to 5-N and the amplitude adjusters 6-1 to 6-N by switching with the switch 8 is as follows. This will be described with reference to FIG.

  In FIG. 8, the first time modulation 23 of time modulation at the time of reception and the second time modulation 24 of time modulation at the time of reception have the same time width in the modulation, and each time width is a transmission pulse. Set to be half of signal 22. Thereby, the reception time of the first modulation 23 of time modulation at the time of reception is the same as the reception time of the second modulation 24 of time modulation at the time of reception.

As described above, in the radar apparatus according to the second embodiment, the reception time of the first modulation 23 of the time modulation at the time of reception is the same as the reception time of the second modulation 24 of the time modulation at the time of reception. When demodulating the time modulation at 15, the demodulation process can be performed with the same weight.
Thereby, the radar apparatus according to Embodiment 2 can operate as a time modulation array antenna.

  The number of time modulations at the time of reception may be two or more, but the time width of one modulation in that case needs to be set to a time width obtained by dividing the time width of the transmission pulse signal by the number of time modulations. is there.

Embodiment 3 FIG.
FIG. 9 is a configuration diagram of the radar apparatus according to the third embodiment.
The radar apparatus according to Embodiment 3 conventionally has a narrow frequency range that becomes clutter-free by limiting the frequency range of target detection under the situation where the targets are facing each other and the radar performance is deteriorated. It solves the problem.
In FIG. 9, a target detector 51 with an identification signal output outputs an identification signal as to whether or not the target is facing and approaching based on the output signal of the frequency converter. In addition, the time modulation operation command unit 52 receives the identification signal from the target detector 51 with an identification signal output and determines whether or not to operate the time modulation on the array antenna. In addition, 1-10 of FIG. 9 and 14-16 are the same components as Embodiment 1, and description is abbreviate | omitted here.

The target detector 51 with output of an identification signal according to the third embodiment can determine whether or not the target is facing and approaching based on the target Doppler frequency.
When the target is facing opposite, the target detector with identification signal output 21 outputs an identification signal 51 s with a facing approach target and outputs it to the time modulation operation command unit 52.
On the other hand, when the target is not facing the opposite approach, the target detector with identification signal output 21 outputs the identification signal 51s without the facing approach target and outputs it to the time modulation operation command unit 22.

  The time modulation operation commander 52 receives an identification signal 51s indicating whether or not there is a facing approach target from the target detector 51 with an identification signal output.

In the time modulation operation command device 52, when the targets are facing each other based on the identification signal 51s, the amplitude phase setting values output from the switch 8 are the phase shifters 5-1 to 5-N and the amplitude adjuster. The transmission is cut off so as not to be transmitted to 6-1 to 6-N, and the execution of time modulation of the array antenna is stopped.
FIG. 10 is a diagram illustrating an example of clutter folding when the time modulation operation command unit 52 stops time modulation, that is, when it is determined that the target is approaching and facing. As a result of stopping execution of time modulation of the array antenna when the target is facing and facing the radar, the radar apparatus according to the third embodiment becomes a normal pulse Doppler radar apparatus.
In this case, target detection is possible in a clutter-free region as shown in FIG.

FIG. 11 shows a case where it is determined that the target is approaching and approaching based on the identification signal 51s. As described above, the time modulation operation command unit 52 does not stop execution of time modulation at the array antenna, and the switching unit 8 It is the figure which showed the return example of the clutter when the amplitude phase setting value output is transmitted toward the phase shifters 5-1 to 5-N and the amplitude adjusters 6-1 to 6-N.
In this case, as shown in FIG. 11, the clutter-free region is narrowed, and the performance of the radar apparatus is degraded.
As described above, when the target is close to the target, the time modulation operation command unit 52 of the present embodiment stops the time modulation, so that the clutter-free region can be suppressed from being narrowed, and the target in the clutter-free region can be suppressed. Detection can be performed.

On the other hand, when the target is not opposite approach based on the identification signal 51s, that is, when there is no target in the clutter-free region, the time modulation operation command unit 52 permits time modulation and the amplitude phase setting value output from the switch 8 Is transmitted toward the phase shifters 5-1 to 5-N and the amplitude adjusters 6-1 to 6-N, and the time modulation of the array antenna is performed.
As described above, when the target is not facing opposite, the time modulation operation command unit 52 of the present embodiment permits time modulation, and thus time modulation is executed. As a result, the radar apparatus according to the present embodiment becomes a low sidelobe radar apparatus and can suppress clutter.

DESCRIPTION OF SYMBOLS 1 Signal generator, 2 Transmitter, 3 Transmission / reception signal separator, 4 Power distribution synthesizer, 5-1-5-N Phase shifter, 6-1-6-N Amplitude adjuster, 7-1-7-N Element antenna, 8 switch, 9-1 to 9-N 1st amplitude phase setting device to Nth amplitude phase setting device, 10 arithmetic device, 14 receiver, 15 demodulator, 16 frequency conversion device, 17 target detection 18-1 Amplitude setting value distribution of the first amplitude phase setting device, 18-2 Distribution of amplitude setting value of the second amplitude phase setting device, 19-1 Phase setting value of the first amplitude phase setting device 19-2 Distribution of phase setting value of second amplitude phase setting device, 20 Receivable time range, 21 Clutter-turned virtual image signal, 22 Target signal, 30 sub-pulse signal, 30t sub-pulse width, 51s identification signal 51 Target detector with identification signal output, 52 During modulation operation command unit, 100 a radar device.

Claims (5)

A signal generator for generating a timing signal;
A transmitter that generates a transmission pulse signal based on the timing signal; and
A transmission / reception signal separator for outputting the transmission pulse signal to a power distribution synthesizer, and outputting a reception pulse signal reflected and received by the transmission pulse signal to a receiver;
A power distribution synthesizer that distributes the transmission pulse signal into N transmission pulse signals and outputs to each of the distributed N phase shifters;
A phase shifter for changing the phase of the transmission pulse signal;
An amplitude adjuster for adjusting the amplitude of the transmission pulse signal output from the phase shifter;
An element antenna that radiates a transmission pulse signal output from the amplitude adjuster to space;
An amplitude phase setting unit comprising a plurality of sets of amplitude phases composed of phases and amplitudes set for the phase shifter and the amplitude adjuster;
A computing device for computing the set of amplitude phases;
A switcher 8 for switching the set of amplitude phases to be set for the phase shifter and the amplitude adjuster in a transmission pulse signal in a time-sharing manner;
A receiver for receiving a reception pulse signal in which a transmission pulse signal modulated in a time division manner in the transmission pulse signal is reflected by a target; and
A demodulator that demodulates the received pulse signal;
A frequency converter for converting the demodulated received pulse signal into a frequency domain signal;
A target detector for detecting a target signal from the signal converted into the frequency domain;
A radar apparatus comprising: 2. The radar apparatus according to claim 1, wherein the demodulator samples the received pulse signal at a time interval of a sub-pulse signal obtained by dividing the transmission pulse signal into a plurality of signals, integrates and demodulates the received pulse signal. Generating a timing signal;
Generating a transmission pulse signal based on the timing signal;
Outputting the transmission pulse signal to a power distribution synthesizer, and outputting the reception pulse signal reflected by the transmission pulse signal to a receiver;
Distributing the transmission pulse signal into N transmission pulse signals and outputting each of the N transmission pulse signals to each of the N phase shifters;
Calculating a plurality of sets of amplitude phases for setting the phase and amplitude of the transmission pulse signal;
Within the transmission pulse signal, switching the set of the calculated amplitude phase in a time division manner, and adjusting the amplitude and phase of the transmission pulse signal;
Radiating the transmission pulse signal, the amplitude and phase of which are adjusted in a time division manner, into space;
Receiving a received pulse signal in which the transmitted pulse signal is reflected by a target;
Demodulating the received pulse signal;
Converting the demodulated received pulse signal into a frequency domain signal;
Detecting a target signal from the signal converted into the frequency domain;
A time modulation method for a radar apparatus, comprising: Time modulation operation that indicates whether or not the set of amplitude and phase to be set for the phase shifter and the amplitude adjuster is switched in a time-sharing manner in the transmission pulse signal based on whether or not the target approaches and approaches The radar apparatus according to claim 1, further comprising a command unit. 5. The radar apparatus according to claim 4, wherein whether or not the target is facing and approaching is determined based on a Doppler frequency of the target signal.

Images