JP3366615B2 - Pulse radar equipment - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pulse radar device which improves range resolution by synthetic band processing.

[0002]

2. Description of the Related Art In a pulse radar device using synthetic band processing, at the time of transmission, as shown in FIG. 9, for N pulses, the transmission frequency is stepped from f ₀ to f _{N -1} for each pulse. Transmission is performed by changing the interval Δf. The transmission signal S _n (t) at that time is expressed by Equation 1. However, here, each signal is expressed as a complex signal in order to simplify the expression by a mathematical expression.

[0003]

[Equation 1]

Where A is the amplitude of the transmission signal, φ _n is the initial phase of each transmission frequency, T _p is the pulse width, and T _pri is the pulse repetition period. When this transmission signal is reflected by a target located at a distance R from the pulse radar device and received by the pulse radar device, the received signal is U _n (t),
It is expressed by Equation 2.

[0005]

[Equation 2]

However, A'represents the amplitude of the received signal, and c represents the speed of light. When the received signal is frequency-converted using the reference signal V _n (t) whose initial phase of each frequency is the same as that of the transmitted signal as shown in Formula 3, the frequency-converted signal W is obtained.
_n (t) is represented by the equation 4.

[0007]

[Equation 3]

[0008]

[Equation 4]

When inverse Fourier transform is performed using the signal of the pulse-modulated portion of W _n (t) expressed by equation 4, the signal P (k) after the inverse Fourier transform is expressed by equation 5. It

[0010]

[Equation 5]

When linear detection is used as the envelope detection method, the signal | P (k) | after the envelope detection is P
The absolute value of (k) is expressed by Equation 6.

[0012]

[Equation 6]

From Equation 6, it is understood that | P (k) | has a peak value when k becomes equal to 2RNΔf / c.
| P (k) | a k which is the peak value when the k _p, as shown in Equation 7 from k _p, it is possible to determine the relative distance R between the pulse radar apparatus and the target.

[0014]

[Equation 7]

Further, the distance resolution ΔR is expressed by equation 8.

[0016]

[Equation 8]

From Equation 8, it is understood that the distance resolution ΔR can be improved by increasing NΔf.

FIG. 10 shows, for example, D.I. R. Wehner
Written by "High-Resolution Rada
r ", Artech House, pp. 197-23.
7, 1955 to improve the distance resolution ΔR and obtain the distance resolution ΔR equal to or smaller than the target dimension.
13 is a conventional pulse radar device that obtains a target range profile as shown in FIG. In FIG. 10, 1 is a timing generator, 2 is a fixed initial phase frequency synthesizer, 3a and 3b are distributors, 4 is a reference intermediate frequency signal generator, 5a and 5b are frequency converters, 6 is a pulse modulator, and 7 is a pulse modulator.
Is a power amplifier, 8 is a transmission / reception switch, 9 is an antenna, 10 is a target, 11 is an intermediate frequency amplifier, 12 is a 90-degree hybrid device, 13a and 13b are phase detectors, and 14a and 14b.
Is an A / D converter, 15 is a synthesis bander, 16 is an envelope detector, and 17 is a display.

Regarding the operation of the above-mentioned conventional pulse radar device,
The description will be made with reference to FIG. With timing generator 1
Is the pulse repetition period T_priFrequency switching signal at intervals
Signal to fixed initial phase frequency synthesizer 2
Control signal to the pulse modulator 6 and transmission / reception switching signal to the transmission / reception switching device
Output to 8. With fixed initial phase frequency synthesizer 2
Is generated by the frequency switching signal from the timing generator 1.
, N types of signals whose frequencies and initial phases are predetermined
One type of signal in a predetermined order, for example,
Pulse repetition period T in order from the lowest frequency_priRaw each time
Output to the distributor 3a. In the distributor 3a, fixed first
The input signal from the phase frequency synthesizer 2 is divided into 2 minutes.
Then, one of them is locally generated by the frequency converter 5a for transmitting signal generation.
As a vibration signal (local oscillation signal for transmission), the frequency converter 5
a, the other is a frequency converter for generating an intermediate frequency signal
Output as 5b local oscillation signal (reception local oscillation signal)
To do. In the frequency converter 5a, for transmission from the distributor 3a
The frequency of the local oscillation signal and the reference intermediate frequency signal generator 4
The frequency of the sum with the frequency of the reference intermediate frequency signal generated in
To generate a transmission carrier signal and output it to the pulse modulator 6.
It In the pulse modulator 6, the input from the frequency converter 5a
For the signal, the pulse modulation signal from the timing generator 1
Pulse repetition period T_priEach time
Pulse width T_pPulse modulation. Pulse modulation
The output signal of the amplifier 6 is input to the power amplifier 7 to increase the power.
The width is calculated and output to the duplexer 8. Transmission / reception switch 8
Then, depending on the transmission / reception switching signal from the timing generator 1,
Pulse repetition period T_priPredetermined for each
The input signal from the power amplifier 7 at time intervals is sent to the antenna 9.
Output. In the antenna 9, the input signal from the duplexer 8
No. is emitted to space as a transmission signal. Transmission signal is the target
10 and antenna reflected by the background and reflected signal
It is received at 9 and output to the transmission / reception switch 8. Transmission / reception switch
In 8, the transmission / reception switching signal from the timing generator 1
Pulse repetition period T_priPredetermined for each
The frequency converter 5 converts the input signal from the antenna 9 at time intervals.
output to b. Further, the frequency converter 5b includes a distributor 3
The local oscillation signal for reception is also input from a. Frequency converter
5b shows the difference between the frequency of the received signal and the local oscillation signal for reception.
An intermediate frequency amplifier that produces an intermediate frequency signal at a frequency of
Output to 11. In the intermediate frequency amplifier 11, the intermediate frequency
Amplifies the power of several signals and outputs the result to the distributor 3b.
Force In the distributor 3b, input from the intermediate frequency amplifier 11
The force signal is divided into two, and phase detectors 13a and 13b are used for each.
Output to. On the other hand, generated by the reference intermediate frequency signal generator 4
The reference intermediate frequency signal is
Is separated into two signals with a phase difference of 90 degrees,
It is output to the detectors 13a and 13b. Phase detector 13
a and 13b, the input signal from the distributor 3b and 9
From the input signal from the 0 degree hybrid device 12, the intermediate frequency
The frequency difference between the frequency of the number signal and the frequency of the reference intermediate frequency signal.
I component, Q component with wave number and 90 degree phase difference from each other
Minute video signal. Generated I and Q video signals
No. has a sampling frequency of 1 / T _pA / D converter 1
4a, 14b, pulse width T_pAt the same interval as
Converted into digital I, Q video signals for each
Output to the synthesis band unit 15. In the synthesis band unit 15, the transmission
Same range view for N transmitted pulses with different frequencies
Inverse Fourier transform of digital I, Q video signals
The pulse width T_pObtain the following distance resolution ΔR
The synthesized band processing is performed, and the result is sent to the envelope detector 16.
Output. In the envelope detector 16, from the synthesis band unit 15
Calculate the amplitude values of all the complex signals that are input and
Output to the display unit 17. In the display unit 17, the envelope detector
The input signal from 16 is displayed.

[0020]

In the synthesis band processing, the relative distance R to the target is at all frequencies of the transmission signal.
In order to obtain the phase information corresponding to, it is necessary to use the reference signal of the same initial phase as the initial phase of the transmission signal of the corresponding frequency for each reception signal of each frequency, as shown in Equations 1 to 4. There is. However, actually, as shown in the conventional pulse radar device using the synthetic band processing of FIG. 10, the transmission signal is generated using the reference intermediate frequency signal and the local oscillation signal for transmission, and the reception signal is used as the reference signal. The local oscillation signal and the reference intermediate frequency signal are used. The frequency and the initial phase of the reference intermediate frequency signal do not change at all, whereas the local oscillation signal for transmission has a pulse repetition period T _pri.
The frequency and the initial phase change every time. Therefore, with respect to the reception signal of each frequency, by using the initial phase φ _{Ln of} the transmission local oscillation signal used when the transmission signal of the corresponding frequency is generated, and the reception local oscillation signal of the same initial phase, It is possible to obtain the phase information corresponding to the relative distance R to the target required for the synthesis band processing. Figure 11
FIG. 4 shows the relationship among a transmission pulse, a reception pulse, a local oscillation signal for transmission, and a local oscillation signal for reception of a pulse radar device using conventional synthesis band processing. In the figure,
St is a transmission pulse, Sr is a reception pulse, Lt is a local oscillation signal for transmission, and Lr is a local oscillation signal for reception. However, here, for the sake of simplicity, the number N of pulses used in the synthesis band processing is set to 3. As shown in FIG. 11, in the pulse radar device using the conventional synthetic band processing, the local oscillation signal for transmission Lt and the local oscillation signal for reception Lr are received.
Since the signal generated by one frequency synthesizer is used by being divided into two by the distributor, the initial phase of both is always the same at all frequencies, and the synthetic band processing can be realized. However, since the signals generated by one fixed initial phase frequency synthesizer are used as the local oscillation signal for transmission Lt and the local oscillation signal for reception Lr, the next transmission frequency is received until the reflection signal from the target for a certain transmission pulse is received. Pulse cannot be transmitted. That is, it can be used only when the relative distance R between the pulse radar device and the target and the pulse repetition period T _pri have the relationship of the _equation 9.

[0021]

[Equation 9]

Therefore, when the relative distance R between the pulse radar device and the target is long, a long pulse repetition period T
_pri is needed. As described above, in the synthesis band processing, since the digital I and Q video signals generated from the reception pulses for the N transmission pulses having different transmission frequencies are subjected to the inverse Fourier transform, the transmission signals of N pulses are required. Is. Therefore, a signal transmission time N times the pulse repetition period T _pri is required to obtain the result of one synthesis band process. Therefore, in the conventional pulse radar device using the synthetic band processing, the pulse repetition period T _pri is long, so that there is a problem that the signal transmission time for obtaining one result is long.

The present invention has been made to solve the above problems, and in a pulse radar device that improves the range resolution ΔR by a synthetic band process, the relative distance R between the pulse radar device and the target and the pulse repetition period. T
_{Even if pri} is in the relation of several 10, the synthetic band processing can be performed, and the relative distance R between the pulse radar device and the target is R.
It is an object of the present invention to obtain a pulse radar device in which the signal transmission time required for one synthesis band process is short even if the pulse radar is long.

[0024]

[Equation 10]

[0025]

A pulse radar device according to a first aspect of the present invention includes a fixed initial phase frequency synthesizer for generating a local oscillation signal for transmission having a predetermined frequency and an initial phase for each predetermined pulse repetition period. , A transmitter that generates a transmission signal pulse-modulated with a predetermined pulse repetition period and pulse width using the local oscillation signal for transmission generated by the fixed initial phase frequency synthesizer, and a pulse repetition period for the transmission signal. Through the transmission / reception switch that switches the transmission / reception signal at the timing of, the antenna that radiates as a transmission wave to the target including the background and receives the transmission wave reflected by the target and the background as the reception wave, and the target obtained in advance A frequency calculator for obtaining frequency information of the received wave using relative distance information; A phase calculator for obtaining the same initial phase become phase and the transmission local oscillation signal from the frequency information and the pulse repetition period of the received wave obtained by the wave number calculator,
Using the frequency information of the received wave obtained by the frequency calculator, an initial phase variable frequency synthesizer that generates a local oscillation signal for reception having a frequency corresponding to the frequency of the received wave at the initial phase obtained by the phase calculator And a receiver for generating digital I, Q video signals from the received waves by using the local oscillation signal for reception, and a synthesis bander for inverse Fourier transforming the digital I, Q video signals. To do.

The pulse radar device according to the second invention is a fixed initial phase frequency synthesizer for generating a local oscillation signal for transmission having a predetermined frequency and an initial phase for each predetermined pulse repetition period, and the fixed initial phase frequency synthesizer. Using the local oscillation signal for transmission generated by the phase frequency synthesizer, a transmitter that generates a transmission signal that is pulse-modulated with a predetermined pulse repetition period and pulse width, and transmits and receives the transmission signal at the timing of the pulse repetition period. The signal is radiated as a transmitted wave to the target including the background through the transmission / reception switch that switches the signal of
And an antenna that receives the transmitted wave reflected by the background as a received wave, a frequency calculator that obtains frequency information of the received wave using relative distance information with a target that is obtained in advance, and the reception that is obtained by the frequency calculator The frequency of the received wave using a phase calculator that obtains the same initial phase as the local oscillation signal for transmission from the frequency information of the wave and the pulse repetition period, and the frequency information of the received wave obtained by the frequency calculator. A fixed initial phase frequency synthesizer for generating a local oscillation signal for reception having a frequency corresponding to the above with a predetermined initial phase, and a receiver for generating digital I, Q video signals from the received wave using the local oscillation signal for reception. A phase corrector for correcting the phase of the digital I and Q video signals using the initial phase obtained by the phase calculator; The digital I whose phase is corrected by the corrector, characterized by comprising a composite band unit for inverse Fourier transform Q video signal.

The pulse radar device according to the third invention is a fixed initial phase frequency synthesizer for generating a local oscillation signal for transmission having a predetermined frequency and an initial phase for each predetermined pulse repetition period, and the fixed initial frequency synthesizer. Using the local oscillation signal for transmission generated by the phase frequency synthesizer, a transmitter that generates a transmission signal that is pulse-modulated with a predetermined pulse repetition period and pulse width, and transmits and receives the transmission signal at the timing of the pulse repetition period. The signal is radiated as a transmitted wave to the target including the background through the transmission / reception switch that switches the signal of
And an antenna that receives the transmitted wave reflected by the background as a received wave, a frequency calculator that obtains frequency information of the received wave using relative distance information with a target that is obtained in advance, and the reception that is obtained by the frequency calculator Using a fixed initial phase frequency synthesizer that generates a reception local oscillation signal of a frequency corresponding to the frequency of the reception wave at a predetermined initial phase using the frequency information of the wave, and using the reception local oscillation signal from the reception wave. A receiver for generating digital I, Q video signals, a synthesis bander for inverse Fourier transforming the digital I, Q video signals, and an output signal of the synthesis bander obtained by the frequency calculator. It is characterized by comprising a distance corrector for correcting the distance by using the frequency information of the received wave.

Further, the pulse radar device according to the fourth aspect of the present invention comprises a plurality of stabilizing oscillators for generating signals having a predetermined frequency and an initial phase, and a predetermined sequence for each predetermined pulse repetition period. A transmission frequency selector that selects a transmission local oscillation signal used for transmission signal generation from signals generated by the plurality of stabilized oscillators, and the transmission local oscillation signal selected by the transmission frequency selector is used. The background is included via a transmitter that generates a transmission signal that is pulse-modulated with a predetermined pulse repetition period and a pulse width, and a transmission / reception switch that switches the transmission / reception signal at the timing of the pulse repetition period of the transmission signal. An antenna that radiates to the target as a transmitted wave and receives the transmitted wave reflected by the target and the background as a received wave, and Of the frequency corresponding to the frequency of the received wave by using the frequency information of the received wave obtained by the frequency calculator and the frequency calculator of the received wave using the relative distance information with the target A receiving frequency selector for selecting a receiving local oscillation signal from the output signals of the plurality of stabilizing oscillators, and a receiving for generating a digital I, Q video signal from the received wave using the receiving local oscillation signal. And a synthesis band device for inverse Fourier transforming the digital I and Q video signals.

[0029]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiment 1. Figure 1 shows the invention
FIG. 1 is a configuration diagram of a pulse radar device showing the first embodiment,
In FIG. 1, 1 to 17 are as described above with reference to FIG.
Is. 18 is a frequency calculator, 19 is a phase calculator
20 is a variable initial phase frequency synthesizer.
This operation is different from the conventional pulse radar device.
The process up to and including the inter-frequency amplifier 11 will be described with reference to FIG.
In the timing generator 1, the pulse repetition period T _priof
Fixed frequency switching signal with fixed initial phase frequency synthesizer
And a variable initial phase frequency synthesizer 20
To the pulse modulator 6, the transmission / reception switching signal
To the duplexer 8. Fixed initial phase frequency synth
The sizer 2 switches the frequency from the timing generator 1.
N, whose frequency and initial phase have been determined beforehand by the signal
A predetermined order of one type of signal among the types of signals
Introduction, for example, pulse repetition period from low frequency
T_priIt is generated for each frequency and used as a local oscillation signal for transmission.
Output to the converter 5a. In the frequency converter 5a, fixed first
Local oscillator for transmission generated by the phase-frequency synthesizer 2
Generated by the reference intermediate frequency signal generator 4 with the frequency of the vibration signal
Transmission of the sum of the frequencies of the reference intermediate frequency signal
A carrier signal is generated and output to the pulse modulator 6. Pa
In the loose modulator 6, the input signal from the frequency converter 5a
On the other hand, by the pulse modulation signal from the timing generator 1,
Therefore, the pulse repetition period T_priPredetermined for each
Pulse width T_pPulse modulation. Of the pulse modulator 6
The output signal is input to the power amplifier 7 to amplify the power.
Output to the transmission / reception switch 8. In the duplexer 8,
The transmission / reception switching signal from the timing generator 1 causes the pulse
Repeat period T_priA predetermined time interval for each
Output the input signal from the power amplifier 7 to the antenna 9.
It At the antenna 9, the input signal from the duplexer 8
It radiates to space as a transmission signal. The transmitted signal is target 10,
And reflected on the background and reflected signals are received by the antenna 9.
It is received and output to the transmission / reception switch 8. With the duplexer 8
Is a transmission / reception switching signal from the timing generator 1,
Pulse repetition period T_priPredetermined time for each
Input signals from the antennas 9 at intervals to the frequency converter 5b
Output. On the other hand, in the frequency calculator 18,
Target 10 obtained by the distance measurement processing and distance tracking processing
Using the relative distance information R'of
Of the transmitted pulse of the previous pulse repetition period
Is a reflected signal from the target 10 that is
The time it takes for Ruth to be reflected from target 10 and received
Pulse repetition period T in_priFind the number m of
The frequency of the received signal is calculated from the transmission frequency at that time. However
Then, the relative distance information R ′ from the target 10 and the true distance between the target 10 and
The difference from the relative distance R is
In, the value of m obtained when R'is R is not different
I have a degree. Information on the obtained m and the frequency of the received signal is
The phase calculator 19 stores the information of the frequency of the received signal in the variable initial position.
It is output to the phase frequency synthesizer 20.

[0030]

[Equation 11]

However, int means rounding down to the decimal point or less. The phase calculator 19 _obtains the frequency f _Ln of the local oscillation signal for reception corresponding to the frequency and the initial phase φ _Ln of the local oscillation signal for transmission used when the signal is transmitted from the information on the frequency of the reception signal. , _M using the frequency calculator 18 and the pulse repetition period T _pri ,
Thus, the phase θ _{n at} which the initial phase becomes the same as the transmission local oscillation signal of the frequency used when the reception signal of that frequency is transmitted is obtained, and the result is output to the variable initial phase frequency synthesizer 20.

[0032]

[Equation 12]

In the variable initial phase frequency synthesizer 20, from the frequency information of the received signal input from the frequency calculator 18, the local oscillation signal for reception of the frequency corresponding to the frequency is calculated by the phase θ calculated by the phase calculator 19. _n is generated as an initial phase and output to the frequency converter 5b. The frequency converter 5 b generates an intermediate frequency signal having a difference between the frequency of the received signal and the frequency of the local oscillation signal for reception generated by the variable initial phase frequency synthesizer 20, and outputs the intermediate frequency signal to the intermediate frequency amplifier 11. The process after the intermediate frequency amplifier 11 is the same as the operation of the conventional pulse radar device.

FIG. 2 shows the relationship among the transmission pulse, the reception pulse, the local oscillation signal for transmission, and the local oscillation signal for reception in the pulse radar device according to the first embodiment of the present invention. In the figure, St, Sr, Lt, and Lr are as described above with reference to FIG. Further, as in the case of FIG. 11, in order to simplify the story, the number of pulses N used in the synthesis band process is set to 3, and the transmission pulse obtained by the equation 11 is the target 10
The number m of the pulse repetition period T _pri within the time required to be reflected and received by is set to 1. Further, the initial phase of the local oscillation signal for transmission Lt generated by the fixed initial phase frequency synthesizer 2 is 0 degree at all frequencies. Further, the signal shown by the dotted line in the figure is for indicating that the initial phases of the local oscillation signal for transmission Lt and the local oscillation signal for reception Lr are the same, and indicates a signal that is not actually generated. .

As can be seen from FIG. 2, the local oscillator for transmission is used.
A frequency sequence for generating the signal Lt and the local oscillation signal Lr for reception.
By providing separate synthesizers, different frequencies
Local oscillation signal Lt for transmission and local oscillation signal Lr for reception
The same pulse repetition period T _priCan be generated within
The reflected signal from the target for a given transmitted pulse
Until it receives a pulse of the next frequency.
There is no need, the relative distance R between the pulse radar device and the target
Pulse repetition period T _priFor
Can be Also, the relative distance information obtained in advance
The initial phase of the receiving local oscillation signal Lr is
Generate a transmit signal of the frequency corresponding to the receive signal of the frequency
Same as the initial phase of the local oscillation signal for transmission Lt used when
Phase θ_nAnd the calculated phase θ_nAs the initial phase
By generating the local oscillation signal Lr for reception,
For the received signal of the wave number, the transmission of the corresponding frequency
Initial of local oscillator signal for transmission used when signal signal was generated
Phase φ_LnAnd the local oscillation signal for reception with the same initial phase
The relative distance to the target required for the synthesis band processing
The phase information corresponding to R can be obtained. for that reason,
Relative distance R between pulse radar device and target and pulse repetition
Cycle T_priEven if there is a relationship of
Processing can be performed and the phase between the pulse radar device and the target
Even if the pair distance R is long, it is necessary for one synthesis band processing.
Therefore, the signal transmission time can be shortened.

Embodiment 2. 3 is a block diagram of a pulse radar device showing a second embodiment of the present invention. In FIG. 3, 1 to 19 are as described above with reference to FIG. 1 and FIG. Reference numeral 21 is a phase corrector. This operation will be described with reference to FIG. 3 up to the envelope detector 16 and earlier, which operates differently from the conventional pulse radar device. In the timing generator 1, the frequency switching signal is sent to the fixed initial phase frequency synthesizer 2a at intervals of the pulse repetition period _Tpri ,
2b, the pulse modulation signal is output to the pulse modulator 6, and the transmission / reception switching signal is output to the transmission / reception switching device 8. In the fixed initial phase frequency synthesizer 2a, the frequency switching signal from the timing generator 1 causes one kind of signals among N kinds of signals whose frequencies and initial phases are predetermined to be set in a predetermined order, for example, from a low frequency. _Is generated for each pulse repetition period T _pri and is output to the frequency converter 5a as a local oscillation signal for transmission. In the frequency converter 5a, the frequency of the local oscillation signal for transmission generated by the fixed initial phase frequency synthesizer 2a and the reference intermediate frequency signal generator 4
A transmission carrier signal having a frequency that is the sum of the frequencies of the reference intermediate frequency signal generated in step 1 is generated and output to the pulse modulator 6. The pulse modulator 6 modulates the input signal from the frequency converter 5a with a pulse modulation signal from the timing generator 1 at a predetermined pulse width T _p for each pulse repetition period T _pri . The output signal of the pulse modulator 6 is input to the power amplifier 7, amplified in power, and output to the transmission / reception switch 8. Transmission / reception switch 8
Then, the transmission / reception switching signal from the timing generator 1 outputs the input signal from the power amplifier 7 at a predetermined time interval to the antenna 9 for each pulse repetition period T _pri . The antenna 9 radiates the input signal from the transmission / reception switch 8 to space as a transmission signal. The transmission signal is reflected by the target 10 and the background, becomes a reflection signal, is received by the antenna 9, and is output to the transmission / reception switch 8. In the transmission / reception switcher 8, the frequency converter 5 transmits an input signal from the antenna 9 at a predetermined time interval for each pulse repetition period T _{pri in accordance with the} transmission / reception switcher signal from the timing generator 1.
output to b. On the other hand, in the frequency calculator 18, the target 1 obtained in advance by distance measurement processing or distance tracking processing is used.
By using the relative distance information R ′ with respect to 0, the received signal is a reflected signal from the target 10 with respect to the transmitted pulse of the previous pulse repetition period, that is, the transmitted pulse is reflected by the target 10 according to Equation 11. The number m of the pulse repetition period T _pri within the time required to receive the signal is calculated, and the frequency of the received signal is calculated from m and the transmission frequency at that time. However, the difference between the relative distance information R ′ with respect to the target 10 and the true relative distance R with respect to the target 10 is given by
In 1, the m obtained when R ′ is R is not different. Information on the obtained m and the frequency of the received signal is output to the phase calculator 19, and information on the frequency of the received signal is output to the fixed initial phase frequency synthesizer 2b. In the phase calculator 19, the frequency f _Ln of the local oscillation signal for reception corresponding to the frequency and the initial phase φ of the local oscillation signal for transmission used when the signal is transmitted from the information on the frequency of the reception signal.
_Ln is calculated, and m is calculated by the frequency calculator 18 and the pulse repetition period T _pri is used.
The phase θ _n that is the same as the local oscillator for transmission of the frequency used when transmitting the reception signal of that frequency is obtained, and the result is output to the phase corrector 21. The fixed initial phase frequency synthesizer 2b generates a receiving local oscillation signal of a frequency corresponding to the frequency from the frequency information of the received signal input from the frequency calculator 18 at a predetermined initial phase, and the frequency converter Output to 5b. The frequency converter 5b generates an intermediate frequency signal having a difference between the frequency of the received signal and the frequency of the local oscillation signal for reception generated by the fixed initial phase frequency synthesizer 2b, and outputs the intermediate frequency signal to the intermediate frequency amplifier 11. The intermediate frequency amplifier 11 amplifies the power of the intermediate frequency signal and outputs the result to the distributor 3
Output to. In the distributor 3, the input signal from the intermediate frequency amplifier 11 is divided into two, and each is divided into phase detectors 13a and 13
output to b. On the other hand, the reference intermediate frequency signal generated by the reference intermediate frequency signal generator 4 is the 90 degree hybrid device 1
At 2, the signal is separated into two signals having a phase difference of 90 degrees and output to the phase detectors 13a and 13b. Phase detector 13
In a and 13b, the input signal from the distributor 3 and 90
From the input signal from the frequency hybrid unit 12, I-component and Q-component video signals having a frequency difference between the frequency of the intermediate frequency signal and the frequency of the reference intermediate frequency signal and having a phase difference of 90 degrees are generated. The generated I and Q video signals have an A / D converter 14 with a sampling frequency of 1 / T _p.
It is input to a and 14b, converted into digital I and Q video signals for each range bin having the same interval as the pulse width T _p, and output to the phase corrector 21. The phase corrector 21 uses the phase θ _n obtained by the phase calculator 19 to calculate the digital I, Q
The phase of the video signal is corrected and the result is output to the synthesis band unit 15. The synthesizing band unit 15 performs a synthesizing band process to obtain a distance resolution ΔR of a pulse width T _p or less by performing an inverse Fourier transform on digital I and Q video signals of the same range bin for N transmission pulses having different transmission frequencies. The result is output to the envelope detector 16.
The processing after the envelope detector 16 is the same as the operation of the conventional pulse radar device.

FIG. 4 shows the relationship among a transmission pulse, a reception pulse, a local oscillation signal for transmission, and a local oscillation signal for reception in the pulse radar device according to the second embodiment of the present invention. In the figure, St, Sr, Lt, and Lr are as described above with reference to FIG. Further, as in the case of FIG. 11, in order to simplify the story, the number of pulses N used in the synthesis band process is set to 3, and the transmission pulse obtained by the equation 11 is the target 10
The number m of the pulse repetition period T _pri within the time required to be reflected and received by is set to 1. In addition, the local oscillation signal for transmission Lt generated by the fixed initial phase frequency synthesizer 2a and the fixed initial phase frequency synthesizer 2b.
The initial phase of the local oscillation signal for reception Lr generated in (3) is 0 degrees at all frequencies.

As can be seen from FIG. 4, the local oscillator for transmission is used.
A frequency sequence for generating the signal Lt and the local oscillation signal Lr for reception.
By providing separate synthesizers, different frequencies
Local oscillation signal Lt for transmission and local oscillation signal Lr for reception
The same pulse repetition period T _priCan be generated within
The reflected signal from the target for a given transmitted pulse
The next frequency pulse must wait for transmission until is received.
There is no need, the relative distance R between the pulse radar device and the target
Pulse repetition period T _priFor
Can be It also has a fixed initial phase frequency synthesizer.
Uses the local oscillator signal for reception Lr generated using a sizer
Even if there is, use the relative distance information obtained in advance
Then, the initial phase of the receiving local oscillation signal Lr is
Used when generating a transmission signal of the frequency corresponding to the reception signal
The same phase as the initial phase of the transmitted local oscillation signal Lt.
Phase θ_nAnd its phase θ_nBefore synthesis band processing
For correcting the phase of digital I and Q video signals
Therefore, the relative distance R to the target necessary for the synthesis band processing is
Corresponding phase information, resulting in pulse
Relative distance R between radar device and target and pulse repetition period
T_priEven if there is a relation of
Can be done, the relative distance between the pulse radar device and the target
Signal required for one synthesis band processing even when R is long
The transmission time can be shortened. In addition, the first embodiment
Then, it corresponds to the relative distance R to the target required for the synthesis band processing
Frequency synthesizer to obtain phase information
Control the initial phase of the local oscillator signal for reception Lr to be generated.
Although it was a correction for the analog signal to control
However, according to the second embodiment, digital I and Q video signals are transmitted.
Compensation for digital signals, that is, signal phase compensation
Therefore, changes in environmental conditions such as temperature inside the radar device
It is possible to reduce the influence of device variations.

Embodiment 3. FIG. 5 is a configuration diagram of a pulse radar device showing a third embodiment of the present invention. In FIG. 5, reference numerals 1 to 18 are as described above with reference to FIGS. 1 and 10. Further, 22 is a distance corrector. This operation will be described with reference to FIG. 5 on and after the frequency calculator 18 different from the operation of the second embodiment. The frequency calculator 18 uses the relative distance information R ′ with the target 10 previously obtained by the distance measurement processing and the distance tracking processing to calculate
Thus, the received signal is the reflected signal from the target 10 for the transmitted pulse of the previous pulse repetition period,
That is, the number m of pulse repetition periods T _pri within the time required for the transmission pulse to be reflected by the target 10 and received.
Then, the frequency of the received signal is obtained from m and the transmission frequency at that time. However, the difference between the relative distance information R ′ with respect to the target 10 and the true relative distance R with respect to the target 10 is m obtained by Expression 11 and m when R ′ is R in Expression 11.
Are not different. The obtained information on the frequency of the received signal is stored in the fixed initial phase frequency synthesizer 2b as m
Is output to the distance corrector 22. The fixed initial phase frequency synthesizer 2b generates a receiving local oscillation signal of a frequency corresponding to the frequency from the frequency information of the received signal input from the frequency calculator 18 at a predetermined initial phase, and the frequency converter Output to 5b. The frequency converter 5b generates an intermediate frequency signal having a difference between the frequency of the received signal and the frequency of the local oscillation signal for reception generated by the fixed initial phase frequency synthesizer 2b, and outputs the intermediate frequency signal to the intermediate frequency amplifier 11. The intermediate frequency amplifier 11 amplifies the power of the intermediate frequency signal and outputs the result to the distributor 3
Output to. In the distributor 3, the input signal from the intermediate frequency amplifier 11 is divided into two, and each is divided into phase detectors 13a and 13
output to b. On the other hand, the reference intermediate frequency signal generated by the reference intermediate frequency signal generator 4 is the 90 degree hybrid device 1
At 2, the signal is separated into two signals having a phase difference of 90 degrees and output to the phase detectors 13a and 13b. Phase detector 13
In a and 13b, the input signal from the distributor 3 and 90
From the input signal from the frequency hybrid unit 12, I-component and Q-component video signals having a frequency difference between the frequency of the intermediate frequency signal and the frequency of the reference intermediate frequency signal and having a phase difference of 90 degrees are generated. The generated I and Q video signals have an A / D converter 14 with a sampling frequency of 1 / T _p.
It is input to a and 14b, converted into digital I and Q video signals for each range bin having the same interval as the pulse width T _p, and output to the synthesis band unit 15. The synthetic band device 15 performs a synthetic band process for obtaining a distance resolution ΔR of a pulse width T _p or less by performing an inverse Fourier transform on the digital I and Q video signals of the same range bin for N transmission pulses having different transmission frequencies. The result is output to the envelope detector 16. The envelope detector 16 obtains the amplitude values of all the complex signals input from the synthesis band device 15, and outputs the result to the distance corrector 22. In the distance corrector 22, m input from the frequency calculator 18 and the pulse repetition period T
_{Using pri} , the correction distance rh is obtained by Expression 13, and the envelope detector output signal after correcting the distance of the correction distance rh is output to the display unit 17.

[0040]

[Equation 13]

The display unit 17 displays the input signal from the distance corrector 16.

The correction distance rh expressed by the equation 13 can be derived as follows. The receiving local oscillation signal generated by the fixed initial phase frequency synthesizer 2b shown in the third embodiment of the present invention and the reference intermediate frequency signal generator 4
The reference signal V ′ _n (t) generated by using the standard intermediate frequency signal generated in (1) is expressed by (14), instead of (3) shown in the conventional example.

[0043]

[Equation 14]

Therefore, the received signal U expressed by the equation 2
_When frequency conversion is performed on _n (t) using the reference signal V ′ _n (t) shown in Expression 14, the signal W ′ _n (t) after frequency conversion is expressed by Expression 15.

[0045]

[Equation 15]

[0046] W is represented by the number 15 'by using the signal of the pulse modulated parts of _n (t), the case of performing an inverse Fourier transform, the signal P after the inverse Fourier transform' (k) is the number 16 expressed.

[0047]

[Equation 16]

When linear detection is used as the envelope detection method, the signal | P '(k) | after the envelope detection is expressed by the equation 17 as the absolute value of P' (k).

[0049]

[Equation 17]

From Equation 17, k is NΔf (2R / c-mT
_It can be seen that | P '(k) | becomes a peak value when it becomes equal to _pri ). The peak value of | P '(k) |
The 'When _p, k' k distances obtained from _p, as shown in Equation 18, shown from the relative distance R between the pulse radar apparatus and the target distance mT _pri c / 2 distance drawn, i.e. the number 13 It is the distance obtained by subtracting the distance rh.

[0051]

[Equation 18]

FIG. 6 shows a target range profile Srp 'before distance correction and a target range profile Srp after distance correction in the pulse radar device according to the third embodiment of the present invention. As shown in Equation 18,
The deviation of the initial phase between the transmission local oscillation signal and the reception local oscillation signal corresponding to each other in the reception signal of each frequency is calculated by the formula 13 in the target range profile.
Therefore, the relative distance R between the pulse radar device and the target can be obtained by correcting the distance rh, and a correct target range profile can be obtained.

Further, in the pulse radar device according to the third embodiment of the present invention, the relationship among the transmission pulse, the reception pulse, the local oscillation signal for transmission, and the local oscillation signal for reception is as shown in FIG. expressed. As can be seen from FIG. 4, the local oscillation signal for transmission Lt and the local oscillation signal for reception Lr
By separately providing the frequency synthesizers for generating, it is possible to generate the local oscillation signal for transmission Lt and the local oscillation signal for reception Lr having different frequencies within the same pulse repetition period T _pri . The pulse of the next frequency does not have to wait for transmission until the reflection signal is received, and the short pulse repetition period T _pri can be used even when the relative distance R between the pulse radar device and the target is long. Even when the receiving local oscillation signal Lr generated by using the frequency synthesizer with the fixed initial phase is used, the relative distance information obtained in advance is used to perform the distance correction after the synthesis band processing, thereby eliminating the error in the distance. If the relative distance R between the pulse radar device and the target and the pulse repetition period T _pri have a relationship of several tens, the synthetic band processing can be performed. Even if the relative distance R between the device and the target is long,
The signal transmission time required for one synthesis band process can be shortened. Further, in the second embodiment, in order to perform the phase correction on the digital I and Q video signals before the synthesis band processing, the phase correction is performed on the digital I and Q video signals at all sample points. Therefore, while it takes a long processing time, in the third embodiment, the synthesis band processing is performed,
Since the correction is performed after the signal on the time axis, that is, the distance is converted, the correction can be performed in a short processing time.

Fourth Embodiment 7 is a block diagram of a pulse radar device showing a fourth embodiment of the present invention. In FIG. 7, reference numerals 1, 3 to 18 are as described above with reference to FIGS. 1 and 10. Further, 23 is a stabilized oscillator group, 24 is a transmission frequency selector, and 25 is a reception frequency selector. This operation will be described with reference to FIG. 7 up to and including the intermediate frequency amplifier 11 that operates differently from the conventional pulse radar device. In the timing generator 1, the pulse repetition period T
Frequency selector 2 for transmitting the frequency switching signal at intervals of _pri
4 and the reception frequency selector 25, the pulse modulation signal is output to the pulse modulator 6, and the transmission / reception switching signal is output to the transmission / reception switching unit 8. In the stabilized oscillator group 23, N kinds of signals whose frequencies and initial phases are determined in advance are generated by the respective stabilized local oscillators in the stabilized oscillator group 23, and all the generated N kinds of signals are selected for transmission frequency selection. 24 and receiving frequency selector 2
Output to 5. The transmission frequency selector 24 uses the frequency switching signal from the timing generator 1 to preset one signal from the input signals from the N types of stabilized oscillator groups 23 for each pulse repetition period T _pri in a predetermined order,
For example, the frequencies are selected in order from the lowest, and the local oscillation signal for transmission is output to the frequency converter 5a. The frequency converter 5a generates a transmission carrier signal having a sum of the frequency of the transmission local oscillation signal from the transmission frequency selector 24 and the frequency of the reference intermediate frequency signal generated by the reference intermediate frequency signal generator 4. And outputs it to the pulse modulator 6.
The pulse modulator 6 modulates the input signal from the frequency converter 5a with a pulse modulation signal from the timing generator 1 at a predetermined pulse width T _p for each pulse repetition period T _pri . Pulse modulator 6
The output signal is input to the power amplifier 7, the power is amplified, and the output signal is output to the transmission / reception switch 8. In the transmission / reception switching device 8, the transmission / reception switching signal from the timing generator 1 causes
The input signal from the power amplifier 7 at a predetermined time interval is output to the antenna 9 for each pulse repetition period T _pri . The antenna 9 radiates the input signal from the transmission / reception switch 8 to space as a transmission signal. Transmit signal is target 1
The antenna 9 is reflected by 0 and the background and becomes a reflected signal.
And is output to the transmission / reception switching device 8. Transmission / reception switch 8
Then, in accordance with the transmission / reception switching signal from the timing generator 1, the input signal from the antenna 9 at a predetermined time interval is sent to the frequency converter 5 for each pulse repetition period T _pri.
output to b. On the other hand, in the frequency calculator 18, the target 1 obtained in advance by distance measurement processing or distance tracking processing is used.
By using the relative distance information R ′ with respect to 0, the received signal is a reflected signal from the target 10 with respect to the transmitted pulse of the previous pulse repetition period, that is, the transmitted pulse is reflected by the target 10 according to Equation 11. The number m of the pulse repetition period T _pri within the time required to receive the signal is calculated, and the frequency of the received signal is calculated from m and the transmission frequency at that time. However, the difference between the relative distance information R ′ with respect to the target 10 and the true relative distance R with respect to the target 10 is given by
In 1, the m obtained when R ′ is R is not different. The obtained information on the frequency of the reception signal is output to the reception frequency selector 25. The reception frequency selector 25 uses the frequency information of the reception signal input from the frequency calculator 18, and uses the frequency switching signal from the timing generator 1 to output N for each pulse repetition period T _pri.
A reception local oscillation signal having a frequency corresponding to the frequency of the reception signal is selected from the input signals from the stabilized oscillator group 23 of the type and is output to the frequency converter 5b. In the frequency converter 5b, the frequency of the reception signal and the reception frequency selector 25
The intermediate frequency signal of the frequency difference of the local oscillation signals for reception selected in step 1 is generated and output to the intermediate frequency amplifier 11. The process after the intermediate frequency amplifier 11 is the same as the operation of the conventional pulse radar device.

FIG. 8 shows the relationship among a transmission pulse, a reception pulse, a local oscillation signal for transmission, and a local oscillation signal for reception in the pulse radar device according to the fourth embodiment of the present invention. In the figure, St, Sr, Lt, and Lr are as described above with reference to FIG. Further, as in the case of FIG. 11, in order to simplify the story, the number of pulses N used in the synthesis band process is set to 3, and the transmission pulse obtained by the equation 11 is the target 10
The number m of the pulse repetition period T _pri within the time required to be reflected and received by is set to 1. The initial phases of the signals generated by the stabilized oscillator group 23 are all 0 degrees. As can be seen from FIG. 8, the local oscillator signal for transmission Lt and the local oscillator signal for reception Lr always generate all the signals used for the synthesis band processing.
Since the necessary signal is selected from among 3 and used, the local oscillation signal for transmission Lt and the local oscillation signal for reception Lr having different frequencies can be generated within the same pulse repetition period T _pri . Further, since the local oscillation signal for transmission Lt and the local oscillation signal for reception Lr are generated by using the same stabilizing oscillator, when the transmission signal of the frequency corresponding to the reception signal of each frequency is generated, The initial phase φ _{Ln of} the transmitted local oscillation signal and the received local oscillation signal of the same initial phase can be used, and the phase information corresponding to the relative distance R to the target necessary for the synthesis band processing can be obtained. . Therefore, the relative distance R between the pulse radar device and the target is
And the pulse repetition period T _pri have a relationship of several tens, the synthetic band processing can be performed, and even if the relative distance R between the pulse radar device and the target is long, the signal required for one synthetic band processing The transmission time can be shortened. Further, in the first, second, and third embodiments, since the frequency of the transmission and reception local oscillation signal Lr is switched by the frequency synthesizer, it takes time for the frequency to stabilize at the time of frequency switching. In the fourth embodiment,
Since all the signals used for the synthesis band processing are always generated by the stabilized oscillator group 23, and the necessary signals are selected from the transmitting frequency selector 24 and the receiving frequency selector 25 and used, high speed is achieved. The frequency can be switched to. Further, the phase control, the phase correction, and the distance correction, which are performed to realize the combined band method in the first, second, and third embodiments, are not necessary.

[0056]

According to the first aspect of the present invention, the synthetic band processing can be performed even when the relative distance R between the pulse radar device and the target and the pulse repetition period T _pri have a relationship of several tens. Even when the relative distance R between the device and the target is long, the signal transmission time required for one synthesis band process can be shortened.

According to the second invention, the relative distance R between the pulse radar device and the target and the pulse repetition period T _pri
Can perform the synthetic band processing even in the case of the relationship of several tens, and shorten the signal transmission time required for one synthetic band processing even when the relative distance R between the pulse radar device and the target is long. You can Furthermore, compared to the first aspect, it is less susceptible to changes in environmental conditions such as temperature in the radar device and variations in equipment.

According to the third invention, the relative distance R between the pulse radar device and the target and the pulse repetition period T _pri
Can perform the synthetic band processing even in the case of the relationship of several tens, and shorten the signal transmission time required for one synthetic band processing even when the relative distance R between the pulse radar device and the target is long. You can Further, compared to the first invention, it is less susceptible to changes in environmental conditions such as the temperature inside the radar device and variations in equipment, and the processing time is shorter than in the second invention.

According to the fourth invention, the relative distance R between the pulse radar device and the target and the pulse repetition period T _pri
Can perform the synthetic band processing even in the case of the relationship of several tens, and shorten the signal transmission time required for one synthetic band processing even when the relative distance R between the pulse radar device and the target is long. You can Furthermore, the first, second and third
Compared with the invention described above, the transmission and the local oscillation signal for reception can be switched at high speed, and the phase control, phase correction, and distance correction performed in the first, second, and third inventions are not necessary.

[Brief description of drawings]

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

FIG. 2 is a diagram showing a relationship among a transmission pulse, a reception pulse, a local oscillation signal for transmission, and a local oscillation signal for reception in the first embodiment of the pulse radar device according to the present invention.

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

FIG. 4 is a diagram showing a relationship among a transmission pulse, a reception pulse, a local oscillation signal for transmission, and a local oscillation signal for reception in the second embodiment of the pulse radar device according to the present invention.

FIG. 5 is a configuration diagram showing a third embodiment of a pulse radar device according to the present invention.

FIG. 6 is a diagram showing target range profiles before and after distance correction in the third embodiment of the pulse radar device according to the present invention.

FIG. 7 is a configuration diagram showing a fourth embodiment of a pulse radar device according to the present invention.

FIG. 8 is a diagram showing a relationship among a transmission pulse, a reception pulse, a local oscillation signal for transmission, and a local oscillation signal for reception in a fourth embodiment of the pulse radar device according to the present invention.

FIG. 9 is a diagram showing a transmission pulse waveform of combined band processing.

FIG. 10 is a configuration diagram showing a conventional pulse radar device.

FIG. 11 is a diagram showing a relationship among a transmission pulse, a reception pulse, a transmission local oscillation signal, and a reception local oscillation signal in a conventional pulse radar device.

FIG. 12 is a diagram showing a target range profile.

[Explanation of symbols]

1 timing generator, 2 fixed initial phase frequency synthesizer, 3 distributor, 4 reference intermediate frequency signal generator, 5 frequency converter, 6 pulse modulator, 7 power amplifier, 8 duplexer, 9 antenna, 10 target, 11
Intermediate frequency amplifier, 1290 degree hybrid device, 1
3 phase detector, 14 A / D converter, 15 synthetic bander, 16 envelope detector, 17 indicator, 18 frequency calculator, 19 phase calculator, 20 variable initial phase frequency synthesizer, 21 phase corrector, 22 Distance corrector, 23 stabilizing oscillator group, 24 transmission frequency selector, 25 reception frequency selector, St transmission pulse, S
r received pulse, Lt transmission local oscillation signal, Lr reception local oscillation signal, Srp 'target range profile before distance correction, Srp target range profile after distance correction.

Front page continued (72) Inventor Isao Tokaji 38-10, Hamura 101, 3 Kamidaira, Fussa, Tokyo 101 (72) Inventor Masayuki Tanaka 33-10, Kamiishakujii, Nerima-ku, Tokyo 10 (56) References JP 10-197626 (JP, A) JP 5-119148 (JP, A) JP 10-39009 (JP, A) JP 7-280923 (JP, A) JP 4-52586 (JP, A) JP-A-3-220482 (JP, A) JP-A-2-24590 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) G01S 7/00-7 / 42 G01S 13/00-13/95

Claims (4)

(57) [Claims] 1. A fixed initial phase frequency synthesizer for generating a local oscillation signal for transmission having a predetermined frequency and an initial phase for each predetermined pulse repetition period, and the local transmission unit generated by the fixed initial phase frequency synthesizer. Via a transmitter that generates a transmission signal that is pulse-modulated with a predetermined pulse repetition period and pulse width using an oscillation signal, and a transmission / reception switch that switches the transmission / reception signal at the timing of the pulse repetition period of the transmission signal. , The frequency information of the received wave is obtained using the relative distance information between the antenna that radiates as a transmitted wave to the target including the background and receives the transmitted wave reflected by the target and the background as the received wave, and the target obtained in advance. A frequency calculator, frequency information of the received wave obtained by the frequency calculator, and pulse repetition A phase calculator that obtains the same initial phase as the local oscillation signal for transmission from the return cycle,
Using the frequency information of the received wave obtained by the frequency calculator, an initial phase variable frequency synthesizer that generates a local oscillation signal for reception having a frequency corresponding to the frequency of the received wave at the initial phase obtained by the phase calculator And a receiver for generating digital I, Q video signals from the received waves by using the local oscillation signal for reception, and a synthesis bander for inverse Fourier transforming the digital I, Q video signals. Pulse radar device. 2. A fixed initial phase frequency synthesizer for generating a local oscillation signal for transmission having a predetermined frequency and an initial phase for each predetermined pulse repetition period, and the local transmission portion generated by the fixed initial phase frequency synthesizer. Via a transmitter that generates a transmission signal that is pulse-modulated with a predetermined pulse repetition period and pulse width using an oscillation signal, and a transmission / reception switch that switches the transmission / reception signal at the timing of the pulse repetition period of the transmission signal. , The frequency information of the received wave is obtained using the relative distance information between the antenna that radiates as a transmitted wave to the target including the background and receives the transmitted wave reflected by the target and the background as the received wave, and the target obtained in advance. A frequency calculator, frequency information of the received wave obtained by the frequency calculator, and pulse repetition A phase calculator that obtains the same initial phase as the local oscillation signal for transmission from the return cycle,
A fixed initial phase frequency synthesizer for generating a reception local oscillation signal of a frequency corresponding to the frequency of the received wave using a frequency information of the received wave obtained by the frequency calculator, and the received wave. To a receiver for generating digital I, Q video signals using the local oscillation signal for reception, and a phase correction for correcting the phases of the digital I, Q video signals using the initial phase obtained by the phase calculator. And a synthesizer band converter for performing an inverse Fourier transform on the digital I and Q video signals whose phases have been corrected by the phase corrector. 3. A fixed initial phase frequency synthesizer for generating a local oscillation signal for transmission of a predetermined frequency and an initial phase for each predetermined pulse repetition period, and the local portion for transmission generated by the fixed initial phase frequency synthesizer. Via a transmitter that generates a transmission signal that is pulse-modulated with a predetermined pulse repetition period and pulse width using an oscillation signal, and a transmission / reception switch that switches the transmission / reception signal at the timing of the pulse repetition period of the transmission signal. , The frequency information of the received wave is obtained using the relative distance information between the antenna that radiates as a transmitted wave to the target including the background and receives the transmitted wave reflected by the target and the background as the received wave, and the target obtained in advance. Using the frequency calculator and the frequency information of the received wave obtained by the frequency calculator, A fixed initial phase frequency synthesizer for generating a reception local oscillation signal having a frequency corresponding to the frequency of the reception wave at a predetermined initial phase, and a digital I using the reception local oscillation signal from the reception wave,
A receiver for generating a Q video signal, said digital I,
A synthesis bander for performing an inverse Fourier transform of a Q video signal, and a distance corrector for correcting the distance of the output signal of the synthesis bander by using the frequency information of the received wave obtained by the frequency calculator. A pulse radar device characterized by being provided. 4. A plurality of stabilizing oscillators for generating signals of a predetermined frequency and an initial phase, and signals generated by the plurality of stabilizing oscillators in a predetermined order for each predetermined pulse repetition period. A transmission frequency selector for selecting a transmission local oscillation signal used for transmission signal generation from among the above, using the transmission local oscillation signal selected by the transmission frequency selector, a predetermined pulse repetition period, and A transmitter that generates a transmission signal that is pulse-modulated with a pulse width, and a transmission / reception switch that switches the transmission / reception signal of the transmission signal at the timing of a pulse repetition period, and radiates it as a transmission wave to a target including the background, the target, And the reception using the antenna that receives the transmitted wave reflected by the background as the received wave and the relative distance information between the target and the target obtained in advance. A frequency calculator for obtaining frequency information of the wave, and using the frequency information of the received wave obtained by the frequency calculator, a local oscillation signal for reception of a frequency corresponding to the frequency of the received wave of the plurality of stabilized oscillators. A receiving frequency selector for selecting from the output signals, a receiver for generating digital I, Q video signals from the received waves using the receiving local oscillation signal, and an inverse Fourier transform for the digital I, Q video signals. A pulse radar device comprising a conversion band converter for conversion.