JPH0664141B2 - Direction identification radar device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of use] The present invention correlates a detection signal of a reflected wave from a target by a radio wave modulated by a pseudo-random code to determine the responsiveness of the existence quadrant determination of the target. The present invention relates to a quadrant identification and direction identification radar device that improves

In the present invention, the direction identification means the determination of the quadrant in which the target object exists.

[Problems to be Solved by Prior Art and Invention]

As a conventional active target detection device, a target detection radar device that uses a single pseudo-random code signal to correlate reflected signals from a target in all directions with the same transmitting and receiving antennas and detects only when the target approaches It has been known. This is to detect that the distance to the target has become equal to or less than a predetermined value, and the direction of the target in that case cannot be detected.

Further, two transmitting and receiving antennas are provided as the target direction detecting device, and two or more pseudo-random code signal projection quadrants and a receiving quadrant in which the receiving antennas are switched at high speed by the transmitting antennas are provided. A prior art has been proposed in which detection quadrant patterns are combined, correlation processing is performed, and a weak reflection signal of a target in the detection quadrant is detected to obtain target approach and target direction information.

This prior art will be described with reference to FIG. This prior art is shown in Japanese Patent Application No. 62-269420 of the present applicant. FIG. 8 is constructed as follows. The antenna section is composed of a pair of transmitting antennas T11, 12 and receiving antennas R13, 14. The oscillating wave from the radio frequency oscillator 15 is sent to the pair of modulators 17 and 18 via the distributor 16, and the output modulated by the external input is sent to the transmitting antennas T11 and T12.

Received inputs from the pair of receiving antennas R13, 14 are sent to the microwave switching circuit 210 together with the clock of the clock generator 200 for switching, and the switching output is sent to the demodulator 21 together with the output of the radio frequency oscillator 15. . The demodulated output of the demodulator 21 is sent to the power distributor 22 and divided into four.

The oscillation output of the voltage controlled oscillator 25 is sent to the first and second pseudo random code generators 24A and 24B, and the first outputs are sent to the modulators 17 and 18, respectively. The second output of each is the correlator 31,
The third output is sent to 34, and the third output is sent to correlators 32 and 33, respectively.
The outputs of the correlators 31 to 34 are transmitted to the determiner 45 via the low pass filters 311, 321, 331, 341.

The judging device 45 includes two comparators 431, 432 and two switches 451, 4
Including 52 and. The outputs of the correlators 31 and 32 are respectively filters 31
Input to comparator 431 via 1,312 and switch compared
451 and the outputs of correlators 33 and 34 are filtered by filter 3 respectively.
It is input to the comparator 432 via 31,341 and compared and output to the switch 452. The output from the clock generator 200 is input to the first and second switches 451 and 452, and the comparator 4
The outputs of 31,432 are input to the switch, and outputs X ₁ and X ₂ are obtained from the first switch 451 and outputs X ₃ and X ₄ are obtained from the second switch 452.

In FIG. 8, the radio frequency (RF) output output from the RF oscillator 15 in the device is divided into two by the distributor 16 and distributed, and then the modulator 17 generates pseudo-random code generated by the first pseudo-random code generator 24A. Transmit antenna after being modulated by code
Radiated upward from T11. Further, after being modulated by the pseudo random code generated by the second pseudo random code generator 24B by the modulator 18, it is radiated downward from the transmitting antenna T12.

The radiated radio wave is reflected by the target object and is received by the left reception antenna R13 or the right reception antenna R14, and the reception radio wave is alternately switched by the microwave switching circuit 210 and then output from the oscillator 15 by the demodulator 21. It is homodyne detected and demodulated using the radio frequency output.

The homodyne-detected signal is divided into four in the power divider 22, and first, in the correlator 31, a signal delayed by the reflection time τ from the reference pseudo-random code (the first output at the left end of 24A) used for radio frequency modulation, Correlation is performed with a code that is the same as the reference and is delayed by 1 bit (the leftmost second output of 24A).

Further, the correlator 32 correlates with the 1-bit lead code (the leftmost third output of 24A). Similarly, the correlator 33 correlates with the 1-bit delay code generated by the pseudo random code generator 24B, and the correlator 34 correlates with the 1-bit advance code.

The outputs from the four correlators 31, 32, 33, 34 are respectively integrated via the low-pass filters 311, 321, 331, 341, and the decision unit 45 decides the direction of the target object.

Next, the operation of the correlator will be described. For example, the correlator 31 multiplies the two inputs via the balanced modulator. An input from the lower side of these two inputs is a pseudo random signal, and an input from the left side is an electron distributor output signal. Moreover, the correlator output is an output obtained by detecting an analog signal of the Doppler frequency if there is a correlation, and a 0 signal (no signal) if there is no correlation.

Next, a method of detecting the existing area of the target object will be described.

Four antennas are installed at 90 ° intervals, and diagonally positioned antennas are used as a pair, and one of the two pairs is used as a transmitting antenna and the other is used as a receiving antenna. Of these, the transmission pattern is always transmitted. In order to distinguish whether there is a reflection in the upper or lower pattern, the pseudo random code is made different for the upper and lower (or left and right) patterns.

On the other hand, the reception pattern is the same as the transmission pattern.
Identification is performed by switching by 210.

The correlators 31, 32, 33, 34 correlate with the same code as each of the two types of pseudo random codes used for modulation of the transmission signal, and with a code delayed by 1 bit and a code advanced by 1 bit. At this time, based on the correlation signal from the correlator, the determination unit 45
Then, multiplication and integration calculation of two sets of signals are performed to obtain signals corresponding to four kinds of combined patterns. For example, when the target approaches from the lower left and the round-trip time of the radio wave between the radar device and the target is within 1-bit correspondence time, the pseudo-random code used to modulate the radio wave emitted from the lower transmission antenna T12. And a code (pseudo-random code) generator 24B having a 1-bit delay from this code and output to the correlator 33) appear remarkably, so that the microwave switch circuit 210 is connected to the left receiving antenna R13. During the period in which the demodulator 21 is connected, the output of the correlator 33 becomes high level as compared with the outputs of other correlators. Therefore, during this period, the target detection signal is output from the comparator 432 in the determiner 45 and sent to the switch 452. This switch 452 switches the output of the comparator 432 to the output terminal X ₃ or another output terminal X ₄ by the timing pulse signal generated by the clock generator 200, and switches the reception antennas R13 and R14 on the left and right sides. Although they are switched in synchronization, the target detection signal appears on the output side of the comparator 432 only while the microwave switch circuit 210 is connected to the left receiving antenna R13, so that the target detection signal is output to the output terminal X ₃ of the decision unit 45. Is output. Similarly, a target detection signal is output to X ₂ if the target approaches from the upper left, X ₁ if the target approaches from the upper right, and X ₄ if the target approaches from the lower right, so that the existence region of the target object can be confirmed.

However, the prior art shown in FIG. 8 makes a detection decision in the target quadrant direction, and there is a problem in responsiveness when high-speed signal processing is required during the intermittent period of the detection signal by switching the receiving antenna. is there. It should be noted that in this prior art, there is a time interruption due to switching of the received signal (switching), which makes continuous operation difficult, and a spike waveform occurs due to switching in the received signal processing,
There is also a problem that an unstable period of the detection signal occurs and, for example, when switching is performed by using a 400 Hz power source, the reception signal is interrupted for 2.5 _msec .

The main object of the present invention is to use beam detection signals in four directions,
Without using a switching mechanism, the target is instantly detected, the angle calculation is performed using each beam detection signal, and the quadrant determination of the target quadrant detection within the set quadrant determination range is performed by quadrant determination by continuous response without interruption time, It is possible to improve the responsiveness of target detection, to accurately judge the quadrant judgment in the target direction near the boundary in the adjacent quadrant, and to set the range of the quadrant detection direction accurately. It is possible to easily change the number of regions and the number of detection quadrants.

[Means for Solving the Problems]

According to the present invention, an antenna unit having two transmitting antennas and two receiving antennas, and obtaining a combined pattern in the target detection quadrant range by the patterns of the transmitting and receiving antennas; RF modulated by code
The transceiver unit that transmits and receives radio waves and continuously outputs the correlation detection between the transmission pseudo random code signal and the reception pseudo random code signal for each receiving antenna, and the correlation signal and the correlation The correlation signals are compared, a signal that instantaneously detects the target object and a composite pattern output signal by the DC voltage of the correlation output of the transceiver unit are used to perform angle calculation in each quadrant, and the target is calculated based on the calculation result. A quadrant determination unit that determines an existing quadrant,
A direction identification radar device comprising:

The configuration of the present invention has the following effects. In each of the transmitting / receiving antenna section and the transmitting / receiving section, a projection pattern of two transmitting antennas and two receiving antennas is used to form a composite pattern in the four-quadrant direction. In addition, two pseudo random codes A and B are individually modulated from the upper and lower sides of the transmitting antenna, and RF radio waves are emitted.

Without switching the reception output of the left and right receiving antennas in time division,
Homodyne detection is performed on the left and right lines continuously in terms of time.

For the local signals to the left and right homodyne detection demodulators, a splitter (25 to 30 dB or more) with good isolation is used to improve the separation of the left and right received signals.

The received signals on the left and right are distributed to respective powers, correlation is performed by the two pseudo random codes A and B, and beam signals in four directions are continuously output as a DC voltage.

In the quadrant determination unit, the beam output signals in the four directions are compared by using the left and right uncorrelated signals, and it is instantly detected that there is a target reflection signal, and a latch signal is sent by a trigger pulse.

The beam output signals in the other four directions are subjected to an angle calculation within each detection quadrant, and the target quadrant range is accurately determined and output as a binary signal.

The target existence quadrant is determined by the latch signal that instantaneously detects the target and the target existence binary signal that calculates the angle within the quadrant, and the target quadrant signal is output.

〔Example〕

FIG. 1 shows a radar apparatus having a quadrant identification function as an embodiment of the present invention.

The transmission / reception antenna unit 10 includes a pair of transmission antennas T (upper) 11,
T (bottom) 12 and a pair of receiving antennas R (left) 13 and R (right)
It is composed of 14 and.

The oscillation wave of the RF oscillator 15 of the transceiver unit 100 is transmitted to the pair of modulators 17 and 18 via the distributor 16, and is modulated by the pseudo random code A and B signals from the pseudo random code generator 24, respectively. , The modulated waves are transmitted antenna T (upper) 1
It is emitted from 1, T (bottom) 12. On the other hand, the reception inputs captured by the pair of reception antennas R (left) 13 and R (right) 14 are transmitted to the demodulator I20 and the demodulator II21, respectively. The demodulation inputs are homodyne-detected by the output from the RF oscillator 15 divided into two by the distributor 19, demodulated, and sent to the respective power distributors I22 and II23.

The distributor 19 is an isolation between the demodulators I and II, for example, 25
In order to obtain ~ 30dB or more, the left and right receiving antennas are separated using a hybrid distributor.

The received signal divided into three by the power distributor I22 is received by the receiving antenna R in the transmitting / receiving antenna pattern shown in FIG.
(Right) The output of 14 is the transmit antenna pattern T (top), T
A composite signal pattern of (bottom) and the receiving antenna pattern R (right), which includes the signals of beam 1 and beam 4.
In the correlators 31, 32 and 33, the reference pseudo-random codes A and B used for modulation of the RF oscillation signal and the code which is the same as one of the references and is delayed by 1 bit are correlated by the conventionally known correlation method. It is then output through the reduction filter LPF.

Therefore, the correlator 31 uses the correlation signal of the pseudo random code A as the output signal of the beam 4 for the low pass filter LPF3.
Input to the quadrant determination unit 400 via 11. Similarly correlator 32
Is a correlation signal of the pseudo-random code B, which is an output signal of beam 1 and passes through the low-pass filter LPF321 to determine the quadrant determination unit 400.
To enter. Further, the received signal divided into three by the power distributor II23 is the output of the receiving antenna R (left) 13 in the transmitting / receiving antenna pattern shown in FIG. 2, and the transmitting antenna patterns T (upper), T (lower) and the receiving antenna. Pattern R (left)
The signals of the beam 2 and the beam 3 are included in the combined reception pattern of and, and the correlations are obtained by using the correlators 34, 35, and 36 in the same manner as described above. Is input to the quadrant decision unit 400 as an output signal of the beam 2 via the low-pass filters LPF341 and 351 respectively. The output signal of each beam is a detection signal in each quadrant direction.
In step 1, predetermined settings and accurate quadrant determination are performed and output as quadrant detection signals to the output terminals X _{1 to} X ₄ .

In the correlators 31, 32, 34 and 35, pseudo-random code
For the received signal that the transmission signal modulated by A, B is reflected from the target object, at the time corresponding to the round-trip propagation distance, for example,
Pseudo-random codes A and B delayed by 1 bit generate an extremely high correlation output signal as a signal in phase. Correlators 33 and 36 take correlation by a pseudo-random code with a 1-bit phase advance, so extremely low-level correlation output for other pseudo-random codes or codes that are out of phase by 1 bit or more. Only happens. This is called a decorrelation signal. For this prototype,
For example, the document “SPREAD SPECTRUM SYSTEMS, R, C,
DIXON ”, and the present invention utilizes this principle.

Therefore, the uncorrelated signal is a non-correlated signal that does not correlate with noise inside the device or an interfering signal from the outside, that is, a non-correlated signal, and the uncorrelated signal depends on the electrical noise environment inside and outside the device. The signal having the adaptive threshold level is compared with each of the correlation signals of the beam 4 and the beam 1 in the signal detector No. 1, and the correlation signal has a round-trip distance to the target within the propagation distance of 1 bit of the code. When the target is located within the set range and the target reflects radio waves, a detection signal is output and sent to the trigger pulse generator 42.

Among them, the correlation output signal is compared with the beam signal of the DC voltage by the comparator of the signal comparator, is sent to the quadrant determiner, is held by the latch signal from the trigger pulse generator, and the state of the output signal in the target presence direction is set to 2 Output from the quadrant determiner by a value signal.

In addition, the angle of the correlation output signal is calculated by the angle calculation unit from the DC voltage of each beam signal, and the target existence direction angle (θ) is calculated.
Is output.

Similarly, in signal detectors No. 2 and 42, beam 3 and beam 2
Is sent to the trigger pulse generator 47. When the detection signal at the moment when the target is detected by any of the beams 1 to 4 is input to the trigger pulse generator 47, a trigger pulse is generated, the latch signal is sent to the quadrant determiner 46, and the window comparator of each quadrant is sent. The output signal from the unit 45 is held.

On the other hand, in the angle calculation unit 43, the correlation outputs of the beams 1 to 4 are converted into DC voltage signals B1 to B4, and the calculation units No. 1 to No. 4,431,
432, 433, and 434, and four beam outputs are input to each arithmetic unit.

The reception level pattern synthesized by the transmitting and receiving antennas in the apparatus of the present invention shown in FIG. 1 is drawn in the shape of arctangent as shown in FIG. In the device of the present invention, each of the computing units No. 1 to No. 4 of the angle computing unit is a universal trigonometric function generator (for example, AD639 type manufactured by Analog Devices, Inc.), and the computation output signal is calculated by the following equation.

The output of each computing unit No. 1, 2, 3, 4 is the quadrant I, shown in Fig. 2 (3).
The output signal is a binary signal of "0" and "1" calculated by the calculator using the reception levels of the reflected radio waves from the target object corresponding to the target object direction (θ angle) of II, III, IV. . Third
The figure shows the calculator No. 1 from the reference direction (angle θ = 0 degree) with positive and negative DC voltage signals corresponding to the θ angle in both left and right directions with the center of each quadrant shown in Fig. 2 (3) as the reference. It is the figure which showed the output characteristic of 1,2,3,4. Similar characteristic diagrams are drawn for quadrants I, II, III and IV.

Fig. 3 shows comparator Nos. 1, 2, 3 using + VREF and -VREF voltage signals from the reference power source 44 for positive and negative DC voltage signals from the arithmetic units No. 1, 2, 3, 4. , 4 compare the signals. At this time, the voltage value of the reference power supply is ± 45 from the reference direction of each quadrant (angle θ = 0 degree) when the output signals of the calculators No. 1, 2, 3, 4 are
Within ± 4 degrees (ie ± tan ^-1 45 °), ± 4
For the voltage value of 5 degrees or more, it becomes the saturation region and the voltage becomes the third
In the figure, the range is "0" and it is not output. For example, if a target exists in quadrant IV shown in FIG. 2 (3), beams 1, 2, corresponding to the direction (θ) of the target object with respect to the reference direction of the quadrant.
Comparing the correlation output signals of 3 and 4 with the arithmetic unit Nos. 1, 2, 3 and 4 and comparing the DC voltage output signals with the comparator power supply Nos. 1, 2, 3 and 4 using the reference power supply voltage + VREF and −VREF As a result, only the output of comparator No.4 outputs a binary signal of "1", and the other comparators No.1,2,3
Is a binary signal of "0".

The relationship between the existence quadrant of the target object, that is, the detection range and the state of the comparator output signal is as shown in FIG.

Next, the principle of angle calculation will be described. This is one of the direction finding measurement methods and uses the principle of the four-terminal / amplitude comparison method. VE, VS, VW, VN in the figure are the output voltages of the antenna pattern in four directions, and these voltages are the four-terminal output signals via the antenna, detector and video amplifier. The antenna pattern in four directions and the block diagram of each detection block are shown in FIGS. 9 and 10. Also, the relational expression between the output voltage value of the 4-way output terminal and the target direction (θ) is Becomes

In FIG. 9, 51, 52, 53, 54 are video amplifiers, 61-64 are detectors, 71-74 are antennas, and 110 is an output terminal group. Further, θ is an angle between the boresight (aiming control) direction and the target direction. FIG. 10 shows north, south, east, and west antenna patterns 121 to 124.

As shown in Fig. 2, when the target exists in the θ angle direction from the center of the IV quadrant, the reflected radio waves from the target are detected by beams 1 to 4 and output as DC voltage signals B1 to B4 at their respective reception levels. It

The arithmetic output signals of the arithmetic units No. 1 to No. 4 are positive and negative DC voltage signals corresponding to the θ angles in both the left and right directions with respect to the center of each quadrant.

The output signal levels of the respective arithmetic units are compared by the comparators 451 to 454 to determine whether or not they are between the positive and negative reference voltages + V _REF and -V _REF from the reference voltage unit 44, and if they are within the positive and negative reference voltages, they are digitalized. Output 1 is output, and if it is outside the positive and negative reference voltages, that is, V _s <−V _REF or V _s > + V _REF , it is output as a binary signal of digital output 0. As described above, the characteristic of the calculator V _SIV or V _S (IV) for the IV quadrant is shown in FIG. 3 as the detection range calculation output. In this case, the accuracy of the calculation decreases when it comes close to the boundary of the calculation, so that the accuracy can be improved by cutting. FIG. 3 shows the output of the arithmetic unit corresponding to the beam output of the IV quadrant of FIG. 2, and similarly, the characteristic diagram can be drawn for the I, II and III quadrants.

As can be seen from FIGS. 2 and 3, + V _REF and −V _REF are set to voltages corresponding to ± tan ⁻¹ 45 °, so only the output of the discriminator in the quadrant where the target is present becomes 1 and other The determiner output becomes 0. For example, if the target exists in the IV quadrant, only the output of the comparator 454 becomes 1.

The comparator output for each quadrant is as shown in FIG.

FIG. 5 shows the window characteristics of the comparator output, and the figure shows the case of the IV quadrant. As is apparent from the figure, the output of this detection comparator shows H (= 1) only between + V _REF and -V _REF , and L (=) outside + V _REF and -V _REF.
0). Generally, a comparator exhibiting such a window characteristic is easily constructed by using a pair of operational amplifiers.

The quadrant determiner 46 holds the binary signals from the comparator Nos. 1 to 4 and 451 to 454 by the latch signal from the trigger pulse generator 42, determines the existence quadrant of the target signal based on the signal holding state, and outputs it. Output to the ends X _{1 to} X ₄ .

_Positive and negative reference voltage values of the reference voltage device 44 -V _REF and + V
_REF is ± 4 from the center of each quadrant, as shown in Fig. 2.
Although 4 quadrants were set with the θ angle of 5 ° as the detection range, the detection range of each quadrant can be changed as necessary by changing the reference voltage value to widen or narrow the comparison range of the window comparator. You can also

FIG. 6 is a signal waveform diagram for explaining the operation of the window type comparator unit shown in FIG.

Further, the configuration showing a detection range calculation output in Figure 7 at calculator V _{S (IV)} characteristic shown in FIG. 3, between the the 0 to-V _REF between the reference voltage range 0 to + V _REF of the comparator It is possible to set the detection quadrant to eight quadrants by setting the voltage value to and comparing. At this time, within the reference voltage value, the digital output “1” is output outside the reference voltage value, that is, V _s.
If <-V _REF or V _s > + V _REF , a binary signal of digital output "0" is output.

〔The invention's effect〕

According to the present invention, a beam detection signal in four directions is used to instantly detect a target without using a switching mechanism,
It is possible to improve the responsiveness of the target detection by performing the angle calculation of each beam detection signal in each quadrant, comparing the existence of the target, and performing the quadrant determination by the continuous response without the interruption time of the target quadrant detection. Further, it is possible to easily change the detection range of the target detection quadrant and increase or decrease the detection quadrant.

[Brief description of drawings]

FIG. 1 is a diagram showing an overall configuration of a direction identification radar device as an embodiment of the present invention, and FIG. 2 is a transmission antenna pattern, a reception antenna pattern, and a synthetic reception pattern which are combined by the transmission / reception antenna of FIG. And the direction of the target object, FIG. 3 is a diagram showing the detection range of the output of the computing unit of FIG. 1, and FIG. 4 is a diagram showing the comparator output of FIG.
FIG. 5 is an explanatory view showing values, FIG. 5 is a detection output waveform diagram of the comparator of FIG. 1, FIG. 6 is a signal waveform diagram for explaining the operation of the window comparator section of FIG. 1, and FIG. 1 is a configuration diagram when the detection range of the comparator in FIG. 1 is limited to 8 quadrants, and FIG. 8 is a diagram showing a conventional type device. FIG. 9 is a block diagram showing the detection block of a four-way antenna pattern, and FIG. 10 is a diagram showing the north, south, east, and west antenna patterns. 10 ... Transmission / reception antenna section, 11,12 ... Transmission antenna, 13,14 ... Reception antenna, 15 ... RF oscillator, 16 ... Distributor, 17,18 ... Modulator, 19 ... Distributor, 20,21 ... Demodulator, 22 , 23 ... Power distributor, 24 ... Pseudo random code generator, 25 ... Voltage controlled oscillator, 31, 32, 33, 34, 35, 36 ... Correlator, 311 to 361 ... Low pass filter, 41, 42 ... Signal detection 43, angle calculator, 431 to 434, calculator, 44, reference power supply, 45, window comparator, 451 to 454, comparator, 46 ... quadrant determiner, 47 ... trigger / pulse generator, 100 ... transceiver Department, 400 ... Quadrant judging section.

Claims (8)

[Claims] 1. An antenna section (10) for obtaining transmission / reception combined patterns by alternately arranging two transmitting antennas and two receiving antennas at 90 ° intervals alternately for transmitting and receiving, and outputs the outputs of an RF oscillator (15) first. 1 is inputted to the first and second modulators via the distributor (16), modulated by the first and second pseudo random codes from the pseudo random code generator (24) and sent to the transmitting antenna. , The second modulator (17,1
8) and the output of the RF oscillator to the demodulator via the second distributor (19) to demodulate the received signals from the two receiving antennas, the first and second demodulators (20, 21). ) And the first
The output of the second demodulator is distributed and the output of the second demodulator is distributed to the first power distributor (22) which is sent to the first, second and third correlators (31, 32, 33). Then, the second power distributor (23) to be sent to the fourth, fifth and sixth correlators (34, 35, 36) and the output of the first power distributor are transferred to the pseudo random code generator ( 24) from which the first and second pseudo-random codes are correlated and the beam signal 4 is respectively passed through the low-pass filter, and
The first and second correlators that output the beam signal 1 and the output of the first power distributor are correlated by a third pseudo random code that is one bit ahead of the first or second pseudo random code. A third correlator that outputs a first decorrelation signal through a low-pass filter and outputs of the second power distributor from the pseudo random code generator (24) Output the beam power 3 and the beam correlator 2 through the low-pass filters, which are correlated with the pseudo random code of Alternatively, a transmitter / receiver unit (100 comprising a sixth correlator that correlates with a third pseudo-random code that is one bit ahead of the second pseudo-random code and outputs it as a second decorrelation signal via a low-pass filter (100 ), The beam signal 4, Beam signal 1, and a first signal detector (41) for detecting the presence of the target in the quadrant by comparison with the first decorrelation signal, the beam signal 2, the beam signal 3, and , A second signal detector (42) for detecting the presence of the target in the quadrant by comparison with the second uncorrelated signal, and a trigger pulse from the outputs of the first and second signal detectors. The trigger pulse generator (47) which sends out the latch signal by the above, and the beam signal 4, the beam signal 1, the beam signal 2 and the beam signal 3 are inputted, and the direct current corresponding to the angle θ from the reference in the existence quadrant of the target is inputted. Voltage signals V _S1 , V _S2 , V _S3 , V _S4 The first, second, third, and fourth arithmetic units (431, 432,
433 and 434), and a window comparator section (45) that compares the output signal level of each of the above arithmetic units with a positive and negative reference voltage and outputs the presence or absence of a target object as a binary signal for each quadrant. , A quadrant judging section (400) comprising a quadrant judging unit (46) which holds the binary signal by a latch signal from the trigger pulse generator, judges the existence quadrant of the target signal according to the signal holding state, and outputs the quadrant. ), And a direction identification radar device. 2. A demodulator for homodyne detection, wherein the transmitter / receiver section performs homodyne detection in two left and right systems continuously in time without switching the reception outputs of the left and right reception antennas in a time division manner. The apparatus of claim 1, wherein the local signal to is for which a distributor is used. 3. The transmitter / receiver unit demodulates the received outputs of the left and right receiving antennas, respectively, and distributes the power to each other, and the correlation is performed by two pseudo random codes, so that the beam signals in four directions are continuous with a DC voltage. The device according to claim 1, which is configured to output the output. 4. The quadrant determination unit compares the first four-direction beam output signals with left and right uncorrelated signals corresponding to left and right receiving antenna outputs, and instantaneously determines that there is a target reflection signal. The device according to claim 1, which detects and sends a latch signal to a quadrant determiner by a trigger pulse. 5. The quadrant judging section judges a target existing quadrant based on a latch signal for instantaneously detecting the target and a binary signal indicating the existence of the target calculated by an angle calculation in the detected quadrant, and outputs the target quadrant signal. The device of claim 4, wherein 6. The quadrant decision unit inputs each of the computing units B1, B2, B in order to compute a target quadrant range using an arctangent function.
3, B4, and the output of each computing unit V _SI , V _SII , V _SIII , V _SIV is the following formula: The apparatus according to claim 5, further comprising an angle calculator that calculates 7. The quadrant determination unit operates so that each arithmetic unit output signal is represented as a positive / negative positive DC voltage signal when the target is present with a deviation from the reference direction by a certain angle. Item 5. The apparatus according to item 5. 8. The quadrant determining unit determines whether or not the output signal level of the arithmetic unit is between positive and negative reference voltages + V _REF and -V _REF from the reference power source in each comparator corresponding to each arithmetic unit. 6. A window comparator unit for comparing and outputting a digital output 1 if it is between both positive and negative reference voltage values, and outputting a digital output 0 if it is outside both positive and negative reference voltage values. apparatus.