JPH0237299A - Proximity fuse - Google Patents

Abstract

PURPOSE:To detect the direction of target by providing a variable attenuator in a path from a directional coupler to the input port of first and second mixers and controlling the rate of attenuation of the variable attenuator based on the output of an integrator by means of a function generator so that false operations due to the reflected waves from the ground or sea surface or the saturation of reception system can be eliminated. CONSTITUTION:The output from an integrator 17 includes the distance information between the missile and the ground or sea surface by means of a tracking loop. Therefore, by controlling by a function generator 27 such that the rate of attenuation of a variable attenuator 13 is inversely proportionate to the square of the distance between the missile and the ground or sea surface, the reception signal input to first and second mixers 5a, 5b caused by the reflected waves is attenuated by the function of the variable attenuator 13 in the inverse proportion to the square of the distance. Since the signal reception intensity of the reflected waves is in the inverse proportion to its distance, the received power by the first and second mixers 5a, 5b caused by the reflected waves does not change regardless of the distance between the missile and the ground or sea surface owing to the usage of the variable attenuator 13.

Description

[Detailed Description of the Invention] [Field of Application] This invention is directed to a target such as an aircraft that is within the effective range of the warhead of a projectile such as an artillery shell or a missile, and It concerns a proximity fuse that detects the direction in which a target is located.

[Conventional technology]

Figure 1O is a diagram showing the configuration of a conventional proximity fuze shown in, for example, Japanese Utility Model Publication No. 62-3741. A directional coupler that takes out the parts.

(3) connects the output of this directional coupler (2) to the antenna (4).
), (5) is the mixer, (6) is the video amplifier, (71U Doppler filter, (81 is the detector, (91 is the comparator, Q (l is the ignition circuit, αI+
is a threshold setter.

Next, the operation will be explained. The signal transmitted from the antenna (4) is irradiated to the target, the reflected signal is received again by the antenna (4), and the circulator (3)
After being mixed with a part of the output of the directional coupler (2) in the mixer (5) and amplified in the video amplifier (6), only the Doppler circumferential mantissa corresponding to the relative velocity difference between the target and the flying object is extracted. The signal passes through the Doppler filter (7), and the amplitude is detected by the detector (8). The output of this detector (8) is compared with the threshold set by the threshold setting device ON using the comparator (9).
When the output of the detector (8) is large, the ignition circuit Q0 is activated and the warhead of the projectile explodes.

The conventional proximity fuse is configured as described above, and detects the Doppler frequency component due to the relative speed difference between the target and the projectile9.
It is now working.

[Problem to be solved by the invention]

However, as mentioned above, since the transmission output is a single frequency, it is easy to discover that the enemy is emitting radio waves, and it is also easy to detect interference waves by using a Doppler filter (7
) No countermeasures can be taken if the frequency is within the range that all passes. Furthermore, since the operating range changes depending on the strength of the reflected power from the target, it is difficult to match the effective range of the warhead.Furthermore, when the projectile flies at low altitude, it is difficult to match the effective range of the warhead. There is a problem that the receiving system may become saturated due to malfunction due to the reflected waves, and
It was not possible to detect in which direction the target was seen from the flying body.

This invention was made to solve the above-mentioned problems, and it is possible to prevent the enemy from discovering the use of W, and to make it less susceptible to interference, as well as to prevent its operation. The purpose is to obtain a close proximity fuze that can clearly set the range, eliminates malfunctions caused by reflected waves from the ground, or the sea surface, and saturation of the receiving system, and has the ability to detect the direction of the target. Means for Solving the Problems] The proximity fuse according to the present invention widens the frequency band by one frequency band by modulating the transmitted 1G wave with a spread spectrum code, making it difficult to be discovered by the enemy and even in the event of interference. , Ukei [
By correlating the signal with the code of 1 bit before the variable vI4i code and 1 bit f) using the output total correlator of the video amplifier of the signal, the interference wave that is not modulated with the same code as the modulation code is despread. Because it goes out of the band of the Doppler filter of 9 proximity fuzes, it is made stronger against interference and 1
It is possible to limit the operating range I#i to a distance range corresponding to the round trip time of radio waves of 1 bit before and after the distance centered on the distance corresponding to the round trip time of the electric wave where only the modulation code and the bit are faint, and Regarding the downward direction of the body, the first
By changing the excavation frequency of the voltage controlled oscillator that drives the code generator of The signal strength of the reflected wave from the sea surface is inversely proportional to the square of the distance between the projectile and the ground or sea surface. The reception signal input to the mixer is kept constant depending on the distance to the ground or sea surface, and for the upward direction of the projectile, the excavation frequency of the clock generator that drives the second code beard i5 is kept constant. This makes it possible to match the above distance range with the effective range of the projectile's warhead.
By comparing the strengths of the received signals obtained by the antenna and the fourth antenna, it is possible to determine the current position of the target as seen from the projectile (whether the target is on the left or on the stone side). In addition, for information on whether there is a target on the lower or upper side, it is necessary to determine whether the received signal of which code is thicker among the codes generated by the first or second code generator. By comparing these combinations of left, right, lower, or upper, it is possible to determine the position of the target as seen from the flying object, that is, in which J81.1 area in the plane directly aligned with the aircraft axis of the flying object. This makes it possible to detect whether it exists.

[For production]

In this invention, for the downward direction of the flying object, the output of one oscillator is the output of the first spread spectrum code generator 'fl: The first 1 bit delayed by 1 bit: M
Spread spectrum fX! by the output of the extension circuit! Then, the first antenna sends 1g, about the direction above the flying object.

The output of the oscillator is spread spectrum modulated by the output of the second spread spectrum code generator < 1 bit delay fc by the output of the third 1 bit delay circuit, and transmitted from the second antenna. Reflected signal? It is received by the third and fourth antennas.

The signal received by the third antenna is homodyne-detected by being mixed with a portion of the output of the transmitter in the first mixer. The detected output is amplified by the first video amplifier and then divided into four equal parts, each of which has a first video amplifier. Second. In the third and fourth correlators, the output of the first code generator, the output of the second 1-bit delay circuit which is delayed by 2 bits from the first code generator, and the output of the second 1-bit delay circuit which is delayed by 2 bits from the first code generator; The output of the ΔT delay circuit delayed by bits+ΔT and the output of the fourth 1-bit delay circuit delayed by 2 bits from the second code generator are correlated, and the signal received by the fourth antenna is It is mixed with a part of the output of the above-mentioned original device in a mixer, and homodyne detection is performed. The detection output is amplified by a second video amplifier, and then divided into three equal parts, each with a fifth one. 6th and 7th
In the correlator, the output of the second code generator, the output of the second 1-bit delay circuit delayed by 2 bits from the first code generator, and the output of the fourth code generator delayed by 2 bits from the second code generator are A correlation is taken with the output of the 1-bit delay circuit. The outputs of these first to seventh correlators are transmitted through first to seventh Doppler filters through which only Doppler frequency band waves corresponding to a preset range of relative velocity difference between the target and the flying object can pass. The outputs are respectively detected by the first to seventh detectors. A constant voltage is added to the outputs of the first and fifth detectors in first and second bias adders, respectively. The output of the third wave detector is compared with the output of the first bias adder in a first comparator, and after the output is integrated in an integrator, voltage control is performed to drive the first code generator. Controls the oscillation frequency of the oscillator and drives the function generator.

A variable attenuator generates attenuation it that is inversely proportional to the square of the distance between the projectile and the ground or sea surface. The outputs of the first and second bias adders are the second to fifth ratios f of the signal detector.
The outputs of the second and fourth and sixth and seventh detectors are compared with the outputs of the second and fourth and sixth and seventh detectors respectively in the first and second bias adders. Each of the second to fifth comparators generates a detection signal when the output becomes larger than the output of . The trigger pulse generator generates a trigger pulse when a detection signal is obtained from any one or more of the second to fifth comparators of the signal detector. In the signal comparators, the magnitudes of two of the outputs of the second, fourth, sixth, and seventh detectors are compared in the sixth to eleventh comparators, and respective comparison signals are generated. The quadrant determiner holds the above six comparison signals using the trigger pulse from the trigger pulse generator, and uses a combination of these held signals to judge the quadrant in which the target exists, and selects the first to fourth signals corresponding to this quadrant. One of the ignition circuits? Activate.

〔Example〕

Hereinafter, Kazuo embodiments of this invention will be explained with reference to the drawings. 1st
In the figure, (1) is the oscillator, (21 is this oscillator +1
A directional coupler for taking out part of the output of 1, (
4a) is a first antenna that emits radio waves into the air below the projectile; (4b) is a second antenna that emits radio waves into the air above the projectile; (4c) and (4d) (5a) and (5b) are the first and second mixers; (6a) and (
6b) Fi first and second video amplifiers, (7a
) to (7g) are the 1st to 7th brown woodpecker filters, (
8a) to (8g) are the first to seventh detectors, (9a)
are the first comparators (10a) to (10d) l”i first
- Fourth ignition circuit.

(12a) and (12b) ii first and second modulators.

03 is a variable f attenuator for attenuating the output of the first modulator (12a), and (14a) and (14b) are the first attenuators for dividing each output of the directional coupler (2) into two.
and the second distributor, (15a) to (15g) are the 1-i%7 correlators, (16a) and (16b) are the first and second bias adders, and σ71 is the integrator Q81.
'i [pressure division control generator, (19a) and (19b) are the first and second code generators, (20a) to (20
d) are the first to fourth 1-bit delay circuits, clυ is a ΔT delay circuit, 4 is a clock oscillator, and C! 3 is a signal detector;
241 is a trigger pulse generator, (2) is a signal comparator,
The clBF'i quadrant determiner (5) is a function generator.

Spread spectrum codes U, M series, Gold codes, etc. can be considered, but all of them generate a high correlation output for a signal that is in phase with the white code, and for signals that are out of phase with the white code by one or more bits. In contrast, only an extremely low cloth output is generated. This invention uses this principle.

After modulating the transmission signal in the first modulator (12a) by the output of the first 1-bit delay circuit (20a), which is delayed by 1 bit from the output of the first code generator (19a), the transmission signal is variable reduced. The first modulator (12a) in the device α3
The output is attenuated and transmitted from the first antenna (4a) K in the downward direction of the projectile.

On the other hand, in the second modulator (12b) by the output of the third 1-bit delay circuit (20c), which is delayed by 1 bit from the output of the second code generator (19b).

The transmission signal is modulated and the radio wave is transmitted upward from the flying object by the second antenna (4b). Here, the first and second code generators (19a) and (19b) generate different codes. These will be referred to as the first code and the second code, respectively.

The reflected waves from the target are transmitted by the third and fourth antennas (4c) and (4d) attached to the left and right sides of the fuselage of the aircraft.
After being homodyne-detected by if and second mixers (5a) and (5b), respectively, it is amplified by first and second video amplifiers (6a) and (6b). 1st
The output of the video amplifier (6a) is the first to fourth correlations 5(
15a) to (15d), the output of the first code generator (19a) and the second 1-bit delay circuit (20
Correlation is taken with the output of b), the output of the ΔT delay circuit 3υ, and the output of the fourth 1-bit delay circuit (20d).

The output of the second video amplifier (6b) is the output of the second code generator (19b) and the second 1-bit delay circuit (2) in the fifth to seventh correlations 5 (15e) to (15g), respectively.
0b) and the output of the fourth 1-bit delay circuit (20d).

However, since the first correlator (15a) takes a correlation with the first code whose phase is one bit ahead of the transmitted signal 16 modulated with the first code, its output is mixed with receiver noise and interference. Only the 1g code is generated by despreading the transmitted signal with good correlation with the signal by the above if code. After passing this signal through a Doppler filter (7a) and a detector (8a), the first bias adder (16a) adds a constant bias to You can set adaptive thresholds according to your needs.

In addition, in the second correlator (15b), since the correlation is taken by the first code that is 1 bit delayed from the transmitted 1g wave modulated by the first code, the first A strong correlation output is generated only when a reflected wave of a wave modulated by the first code from the target appears in a range of l bits before and after the code. Since this signal includes a Doppler frequency corresponding to the relative velocity difference between the target and the flying object, it passes through a Doppler filter (7b) and is detected by a detector (8b).

Furthermore, in the third correlator (15c), correlation is taken by the first code delayed by 1 pit+ΔT from the transmitted wave modulated by the first code.

1 before and after the first code delayed by 1 bit + ΔT from the transmitted signal
A strong correlation output is generated only when a reflected wave of a modulated wave according to the first code appears in the bit range. FIG. 2 shows time and the first bias adder, the second . This is a diagram showing the relationship between the output voltage of the third detector and the output voltage of the bias adder (16a).
C indicates the output voltage of the third detector (8C), and 2 indicates the tracking distance. As shown in Figure 2, the third detector (
8C) Since the correlation output can be obtained at the farthest distance from the projectile, the object will fly at a low altitude, and the ground or ?
When the reflected wave from the 1g plane is obtained within the round trip distance of the radio wave corresponding to the above range, a correlation output will be generated. Since this signal contains a Doppler frequency corresponding to the velocity of the projectile, it passes through a Doppler filter (7C), is detected by a detector (8C), and is detected by the first comparator (9a).
is compared with the output of the bias adder <16a).

In the third correlator (15c), correlation is taken by the output of the ΔT delay circuit, so signals due to uncorrelated internal noise of the receiver, external harmonic waves, and uncorrelated transmitted signals are The 1g signal, which is despread and has only the passband of the Doppler filter (7c), is sent to the detector (8c) and added to the output of the Doppler frequency component of 1 reflected wave! and the detector (8
It appears in the output of c). Therefore, the first comparator (9
The output of a) has the receiver's internal noise, external interfering signal components and uncorrelated transmitted signal fractions subtracted, and purely reflected signal components are celebrated. This signal is integrated by an integrator αD and input to a voltage controlled oscillator u8 to control its oscillation frequency. The relationship between the input voltage and the output oscillation frequency of the military pressure controlled oscillator aS is as shown in Fig. ) is small, the output of the integrator αD is 0■, and the output oscillation frequency of the X-pressure control oscillator aS is a corresponding frequency fL. However, the projectile flies at a low altitude and generates an output in the third detector (8c), causing the I-th bias adder (16a
), the output voltage of the first comparator (
9a) outputs the differential pressure between the two. This output voltage is integrated by the integrator α and input to the one-pressure control excavator, so its output frequency increases as shown in FIG. Since the first code generator (19a) is operated by the α-th 'pressure control excavator', an increase in frequency means that the period of one bit becomes shorter, and the corresponding radio wave is The round-trip distance also becomes shorter, and the output time width of the third detector (8C) shown in Figure 2 C becomes narrower. Therefore, the output voltage of the third detector (8c) decreases, and this 'The voltage will balance the distance shown in Figure 2 at two points. That is, the lid pressure control oscillator marked a, the first code generator (19a), the first and second 1-bit delay circuits (20a) and (20b), the ΔT delay circuit QD,
m3 (7) correlator (15c), third Doppler filter (7c), third detector (8c), ratio ff! (
9a).

and from the integrator +171, the first video amplifier (6a)
A loop will be formed to track reflected waves from the ground or sea surface that are input from the ground, and this tracking distance will automatically change depending on the position of the flying object.

Incidentally, the output of the integrator 1171 includes information on the distance between the projectile and the ground or sea surface due to the tracking loop. Therefore, by using the function generator @i], the first and second The reception input to the mixers (5a) and (5b) by reflected waves from the ground or sea surface is attenuated inversely proportional to the square of the distance between the flying object and the ground or sea surface by the action of the variable attenuator αJ. It turns out. However,
Since the received intensity of reflected waves from the ground or sea surface is inversely proportional to the square of the distance, by using a variable attenuator (13),
The power received by the reflected waves to the first and second mixers (5a) and (5b) does not change depending on the distance between the flying object and the ground or sea surface.

Next, in the fourth correlator (15d), the excavation frequency f.

A second code generator driven by a clock oscillator
A second sign generated by g% (19b) is correlated. In the fourth correlation 0 (15d), since the correlation is taken by the second code which is delayed by 1 bit from the transmitted wave modulated by the second code, the signals before and after the second code which is delayed by l bit from the transmitted wave are A strong correlation output is generated only when the reflected wave of the modulated wave from the target according to the second code appears in the 1-bit range. Since this signal includes a Doppler frequency corresponding to the relative speed difference between the target and the flying object, it passes through a Doppler filter (7d) and is detected by a detector (8d). Fifth
The correlator (15e) takes the correlation with the second code whose phase is one bit ahead of the transmitted signal modulated with the second code, so its output is uncorrelated with the receiver noise and the interference signal. Only a signal obtained by despreading the transmitted signal by the second code described above is generated. This signal is filtered by a Doppler filter (
7e) and a detector (8e), by adding a constant bias in the second bias adder (16b),
An adaptive threshold can be set according to the radio wave environment inside and outside the proximity fuse.

In addition, in the sixth correlator (15f), since the correlation is taken by the first code delayed by l bits from the transmitted wave modulated by the first code, the first code delayed by 1 bit from the transmitted wave is A strong correlation output is generated only when a reflected wave of a modulated wave of the first code from the target appears in the range of 1 bit before and after. This signal contains a Doppler frequency corresponding to the relative velocity difference between the target and the projectile, so it is filtered by a Doppler filter (
7f) The signal passes through k and is detected by the detector (8f).Furthermore, in the seventh correlator (15g), the signal is modulated by a second code that is one bit later than the transmitted wave modulated by the second code. Since the correlation is taken, a strong correlation output is generated only when the reflected wave of the modulated wave from the target by the second code appears in the transmit (before and after the second code that is 1 bit behind the g-wave) bit range. This signal contains a Doppler frequency corresponding to the relative velocity difference between the target and the projectile, so it is filtered by a Doppler filter (
7g) and is detected by a detector (8g).

Figure 4 shows the details of the signal detector (to), and A and D in Figure 7 are the first and second bias detectors (1
The outputs of 6a) and (16b) are IBIO, E and F.
VX, 2nd. 4th. 6th and 7th voltage detector (8b),
(8ti), (8f) and (8g), and (9b) to (9e) are the second to fifth comparators. In the second comparator (9b) the first bias adder +1
The output A of 6a) and the output B of the second detector (8b) are compared. In the second correlator (15b), correlation is taken by the output of the second 1-bit delay circuit (20b), so
Signals due to uncorrelated receiver internal noise, external interference waves, a modulated wave of the first code with a zero phase shift, and a modulated wave of the second code are despread and sent to the Doppler filter (7b). A signal of only the passband is sent to the detector (8b), added to the output of the Doppler frequency component from the target, and appears at the output of the detector (8b). Therefore, the output of the second comparator (9b) is obtained by subtracting the internal noise of the receiver, the external interference signal component, and the uncorrelated transmitted signal component, so that only the target signal component appears, and the detected signal G is obtained. In the third comparator (9c), the first bias adder (
16a) and the output C of the fourth detector (8d) are compared. Since the fourth correlator (15d) performs correlation using the output of the fourth 1-bit delay circuit (20d),
Uncorrelated internal receiver noise, external interference waves, and
The signal generated by the modulated wave with the code of It is added to the output of the Doppler frequency component of , and appears in the output of the detector (8d). Therefore, the output of the comparator (9C) of 哗3 is equal to the internal noise of the receiver 1 the external interference 6
signal components and uncorrelated transmitted signal components are subtracted,
Purely only the target signal component appears, and a detection signal H is obtained. The fourth comparator (9d) has a second bias adder (
16b) and the output E of the sixth detector (8f) are compared. In the sixth correlator (15f), correlation is taken by the output of the second 1-bit delay circuit (20b), so
Signals due to uncorrelated receiver internal noise, external interference waves, modulated waves of the first code that are out of phase, and modulated waves of the second code are despread and passed through a Doppler filter ( 7f)
The signal of only the passband is sent to the detector (8f), added to the output of the Doppler frequency component from the target, and appears at the output of the detector (8f). Therefore, the fourth ratio e
The output of the receiver (9d) is obtained by subtracting the internal noise of the receiver, external interference signal components, and uncorrelated transmitted signal components.
Purely the target signal component is subtracted, only the target signal component appears purely, and the detection signal I is obtained. The fifth comparator (
In step 9e), the output of the second bias adder (46b) is compared with the output F of the seventh detector (8g). In the seventh correlator (15g), the fourth 1-bit delay circuit (20d)
Since the correlation is taken by the output of
The signal is despread by the phase-shifted modulated wave of the second code, and the signal only in the passband of the Doppler filter (7g) is sent to the detector (8g), where it is detected by the Doppler frequency component from the target. It is added to the output and appears at the output of the @ wave device (8g). Therefore, the output of the fifth comparator (9e) is
The internal noise of the receiver, the external interference signal component, and the uncorrelated transmitted signal component are subtracted, and only the target signal component appears, and the detected signal J is obtained.

Next, Fig. 5 is a diagram showing details of the trigger pulse generator @, and c78 in Fig. 9 is an OR circuit, c! 9Vi pulse generator. When a detection signal is obtained from any one or more of the second to fifth comparators (9b) to (9e), the O)L circuit @ activates the pulse generator ■ to generate a trigger pulse K with a constant pulse width. to occur.

In addition, since the second correlation 5 (15b) is correlated with the first code that is υΔT before the third correlator (15c), the correlation output is sent to the second detector (8b). The distance range from which this can be obtained also varies depending on the flight altitude, and is located inside the correlation output range of the third detector (8C), as shown in FIG. As a result, even if the projectile attempts to fly to a low altitude ft, the output of the second V detector (8b) becomes large due to the reflected waves from the ground or sea surface, and the second comparator (9b) detects it. The signal G will no longer be generated erroneously, and the second detector (8b) will receive an output only when the target appears within the distance between the projectile and the ground or sea surface. Similarly, the sixth correlator (15f)
Also, since the correlation is taken by the first code ΔT earlier than the correlator (15c) of W, 3, the half-6 test e
The distance range in which the correlation output can be obtained from the detector (8f) also varies depending on the distance r[, and is located inside the correlation output range of the third detector (8C) as shown in Figure 2. . As a result, even if the flying object attempts to fly at a low altitude, the output of the sixth detector (8f) increases due to the reflected waves from the ground or sea surface, and the fourth comparator (9d) detects the second wave. (2) will no longer occur erroneously, and the sixth detector (8f) will receive an output only when the target appears within the distance between the flying object and the ground or sea surface.

Next, Figure 6 shows a cross section of the spacecraft directly along the 8i axis, viewed from the rear of the spacecraft.

The y-axis represents the left-right axis, and the two axes represent the up-down axis. positive direction of the y-axis,
Namely, the right direction and the downward direction of the two axes.

In other words, the quadrant defined by the downward direction is the first quadrant,
Below, the 1st (2) and (2) quadrants are defined as shown in the same figure. In the figure, L represents the body of the flying object, and (
4a) to (4d) indicate first to fourth antennas. In addition, the male figure 7 is the first to fourth antennas (4a) to (4d).
), and P in the figure is a pattern in which the first antenna (4a) radiates the signal modulated with the first code to the lower part of the body of the spacecraft, and PB is the pattern in which the second antenna (4b) radiates a V-tuned signal with the second code to the upper part of the fuselage of the aircraft, and Po is the pattern in which the signal is received by the third antenna (4C) installed on the left side of the fuselage. Pattern, PD is the reception Bakun by the 4th antenna (4d) installed on the right side of the fuselage, h
The transmission/reception pattern, that is, the beam ■, is transmitted by the first antenna (4a) below Fi and received by the fourth antenna (4d) on the right side.

P is transmitted downward by the first antenna (4a).

The transmission/reception combination pattern received by the third antenna (4C) on the left, that is, the beam "k+Po" is transmitted upward by the second antenna (4b), and then transmitted to the third antenna (4C) on the left.
C) received by the friend transmitting/receiving combination pattern, that is, the beam ■
, PH indicates the transmission/reception combination pattern transmitted upward by the second antenna (4b) and received by the fourth antenna (4d) on the right side, that is, beam ■.

By the way, the output of the second detector (8b) is the signal received by the third antenna (4C) on the left side correlated with the first code, so it corresponds to the output of beam 4
The output of the detector (8d) is sent to the third antenna (4C) on the left.
), which is correlated with the second code, corresponds to the output of beam ■, and is detected by the sixth detector (8f
) is the signal received by the fourth antenna (4d) on the right side correlated with the first code, so it corresponds to the output of beam I, and the output of the seventh detector (8g). Since this is the signal received by the fourth antenna (4d) on the right side, which is correlated with the second code, it corresponds to beam ■.

FIG. 8 is a diagram showing the details of the signal comparator (to), and B, O, E, and F in FIG. 4th. Sixth and seventh detectors (8b), (8d), (8f) and (8g
), and (9f) to (9k) are the outputs of the 6th to 1st
1 comparator. In the sixth comparator (9f), the output B of the fourth detector (8b) is compared to the output B of the fourth detector (8b).
When the output C of step d) is larger, a comparison signal Mi of no-impel is generated. In the seventh ratio f2 (9g), the output B of the second detector (8b) is compared to the output B of the sixth detector (8b).
When the output B of f) is larger, a comparison signal N of no-impel is generated. In the eighth comparator (9h), the second
The output B of the seventh detector (8b) is compared to the output B of the seventh detector (8b).
) is a high level comparison signal 0 when the output F is larger.
All occur. In the ninth ratio V detector (91), when the output E of the sixth detector (8f) is thicker than the output 0 of the fourth detector (8d), the Generates a special order P. The first O comparator (9j) outputs a high-level comparison signal Q when the output F of the seventh detector (8g) is higher than the output C of the fourth detector (8d). Occur. The eleventh comparator (9k) generates a Vine Bell comparison signal R when the output F of the seventh detector (8g) is thicker than the output E of the sixth detector (8f). do.

In addition, FIG. 9 is a diagram showing details of the quadrant determiner (to), and M-R in FIG.
The comparison signals which are the outputs of f) to (9k) are shown, and in FIG. 1, the trigger pulse which is the output of the pulse generator (2) shown in FIG. 5 is shown.

(30a) to (30f) are the 1st-i6 retainers, (
31a) to (31f) are the 1st-i6th inverters, (32
a) to (32d) are first to fourth AND circuits. When the trigger pulse K is input, the first to sixth retainers (30a) to (30f) have the same pulse width as the trigger pulse if the input signal M-L of each retainer is at a high level. Generates a signal that remains high level only for a corresponding period of time. Also.

First to sixth inverters (31a) to (31f) F'i
If each input is at a high level, a low level output is generated, and if each input is at a low level, a high level output is generated. Next, the first to fourth AND circuits (32a) to (32d) each generate a high-level judgment signal 5-v6 only when all three inputs thereof are at high level, and
ignition circuits (10a) to (10d) are activated.

Here, if the target exists in the first quadrant, for example, the signal from the beam (1) will be received more strongly than the signals from the beams (2) to (2). That is, the second. 4th. The sixth and seventh detectors (sb), (sd), (8f) and (8
Among the outputs of g), the output of the sixth detector (8f) is the largest. Therefore, in the signal comparator (c), the seventh
and the output of the ninth ratio 1<6 (9g) and (91) is
The output of the eleventh comparator (9k) becomes low level. The 7th and 9th of these three signals
The outputs of the comparators (9g) and (91) are input to the first AND circuit (32a) at the same level, and the output of the eleventh comparator (9k) is input to the first inverter (:Ua). The first AND is inverted from low level to high level.
Since it is input to the circuit (32a), all three inputs of the first AND circuit (32a) are at high level,
Since this output is also at a high level, the first ignition circuit (1
0a) will be activated.

However, the output of the @7 comparator (9g) is transferred to the third inverter (
31C) and becomes low level, the second A
If the output of the ND circuit (32b) is at a high level,
Ignition circuit (iob) H does not operate. In addition, the output of the 7th ninth comparator (91) is inverted by the fifth inverter (31e) and becomes a low level and is input to the third AND circuit (32c), so its output does not become a high level. , 3rd
The ignition circuit (IOC) does not operate. Furthermore, since the output of the 11th comparator (9k) is inputted to the 0 circuit (32d) to the 4th A while remaining at a low level, the output of the 4th ignition circuit (10d)
) also does not work. That is, when the target exists in the first quadrant, only the first ignition circuit (10a) is activated. Hereinafter, the same applies to the first part. When the target exists in the 2nd or 2nd quadrant, i2. Only the third or fourth ignition circuit (Job), (10c) or (10d) will be activated, and the direction fta in which the target exists can be determined.

Note that the second and fourth 1-bit delay circuits are the same as the first and third 1-bit delay circuits.
Although all the outputs of the 1-bit delay circuit are delayed by 1 bit, it is only necessary to delay the output by 2 bits of the spread spectrum codes of the first and second code generators.

In the above embodiment, the variable attenuator a3 and the first modulator (1
2a) and the first antenna (4a), the directional coupler (2) to the mixer (5a), such as between the first distributor U4a) and the first modulator (12a). (5b) It may be provided in the path leading to the input end.

〔Effect of the invention〕

As described above, according to the present invention, since the transmitted waves are spread spectrum, the transmission power density per unit frequency band can be kept small, making it difficult for the enemy to detect.
In addition, even in the case of interference, by taking the correlation inside the proximity fuze, the proximity fuze's effective l ：l Calibration detection range transmission f Since it is suppressed within the round trip distance of the 71c wave corresponding to the phase of 1 bit before and after the phase that is 1 bit behind the sub-code, the target detection range is matched with the effective range of the warhead. and when the flying object attempts to fly at a low altitude, the oscillation station vvi of the 'fσ pressure control oscillator O11 changes in the downward direction of the flying object according to the altitude, and the ground Alternatively, the range of reflected waves from the sea surface can be automatically tracked, and the effective target detection range can be set to be smaller than the distance to the ground or sea surface, completely preventing malfunctions caused by reflected waves from the ground or sea surface. In addition, it is possible to prevent saturation of the receiving system by stipulating that the received signal input power to the mixer due to reflected waves from the ground or sea surface is constant regardless of changes in the distance between the flying object and the ground or sea surface. This allows the dynamic range of the receiving system to be small, and since the clock oscillator's button oscillation frequency is constant and variable in the upward direction of the object to be flown, the same effective target detection range as when flying in the sky can be secured. Furthermore, it has the effect of being able to identify in which direction the target is located when viewed from the flying body.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing the configuration of a proximity fuse according to an embodiment of the present invention, and FIG. 2 is a diagram showing a time and first bias adder and a second bias adder.
Figure 3 is a diagram showing the relationship between the output voltage of the t-pressure section j and the output voltage of the source oscillator. Diagram showing the configuration of the vessel, No. 5
The figure is a diagram showing the configuration of the trigger pulse generator, and Figure 6 is a cross-sectional view of the flying object, showing the definition of the 1t-itvt limit, and a diagram showing the positions of the first to fourth antenna installations.
FIG. 7 is a diagram showing the transmission pattern, reception pattern, and transmission/reception combination pattern by the first to fourth antennas, FIG. 8 is a diagram showing the configuration of the signal comparator, and FIG. 9 is a diagram showing the configuration of the quadrant determiner. , FIG. 10 is a diagram showing the configuration of a conventional proximal 1g tube. In the figure, (1) is the @part, and (2) is the directional coupler. (4) is an antenna, (5) is a mixer, (6) is a video amplifier, (7) is a Doppler filter, (8) is a detector, (
9) is a comparator, 0α is an ignition circuit, Ua is a modulator, 11 is a variable damper, [14 is a distributor, US is a correlator, ue is a bias adder, 0 is an integrator, Qe is a voltage controlled oscillator,
q9 is a code generator, ■ is an l-bit delay circuit, e211
is a ΔT delay circuit, @ is a clock oscillator, @ is a signal detector, @ is a trigger pulse generator, c! ! i is a signal comparator, 1
28 is a quadrant judger, @ is Seki #! 1 is a generator, Suit is an OR circuit, @ is a pulse generator, ■ is a holder, 60 is an inverter, and (To) is an AND circuit. Note that in FIG. 1, the same or corresponding parts are designated by the same reference numerals. Inspection diagram TJ voltage Voltage diagram Fl IUV

Claims (2)

[Claims] (1) a voltage controlled oscillator; a first code generator driven by the output of the voltage controlled oscillator to generate a spread spectrum code; and a first code generator that generates a spread spectrum code by delaying the output of the first code generator by one bit. a first 1-bit delay circuit;
A second 1-bit delay circuit generated by further delaying the output of the 1-bit delay circuit by 1 bit, and a ΔT delay generated by delaying the output of the second 1-bit delay circuit by a minute time ΔT of 1 bit or less. a circuit, an oscillator that generates a transmission signal, a directional coupler that branches a part of the output of the oscillator, a first divider that divides the output of the directional coupler into two, and the first distribution a first modulator that spread-modulates one output of the transmitter with the output of the first 1-bit delay circuit; a first antenna, a clock oscillator, a second code generator that is driven by the output of the clock oscillator and generates a spread spectrum code different from the first code generator, and the second code generator. a third 1-bit delay circuit that generates the output by delaying the output of the third 1-bit delay circuit by 1 bit; a fourth 1-bit delay circuit that generates the output by further delaying the output of the third 1-bit delay circuit by 1 bit;
a second modulator that spread-modulates the other output of the distributor with the output of the third 1-bit delay circuit; and an upper body part of the aircraft body that transmits the output of the second modulator in the target direction. a second antenna attached to the body, and a third antenna attached to the left side of the fuselage of the flying object, which receives radio waves transmitted in the target direction by the first and second antennas and reflected from the target; a second distributor that divides a portion of the output of the oscillator branched by the directional coupler into two;
a first mixer that mixes the output of the third antenna and one output of the second distributor; a first video amplifier that amplifies the output of the first mixer; and a first video amplifier that amplifies the output of the first mixer; a first correlator that correlates the output of the amplifier with the output of the first code generator; and a first correlator that correlates the output of the first Biot amplifier with the output of the second 1-bit delay circuit. 2
a correlator, an output of the first video amplifier and the ΔT
a third correlator that correlates with the output of the delay circuit; a fourth correlator that correlates the output of the first video amplifier with the output of the fourth 1-bit delay circuit; and a fourth antenna attached to the right side of the fuselage of the flying object that receives radio waves transmitted in the target direction by the second antenna and reflected from the target, and the output of the fourth antenna and the second distribution. a second mixer for mixing the output of the second mixer with the other output of the second mixer; a second video amplifier for amplifying the output of the second mixer;
a fifth correlator that correlates the output of the code generator; a sixth correlator that correlates the output of the second video amplifier with the output of the second 1-bit delay circuit; a seventh correlator that correlates the output of the second video amplifier with the output of the fourth 1-bit delay circuit, and the outputs of the first to seventh correlators are connected to first to seventh Doppler filters, respectively. a first to seventh detectors that input through the first to seventh detectors, a first bias adder that adds a constant bias voltage to the output of the first detector, and a constant bias voltage to the output of the fifth detector. a second bias adder that adds the , a first comparator that compares the output of the first bias adder and the output of the third detector, and integrates the output of the first comparator. and compares the output of the integrator that controls the oscillation frequency of the voltage controlled oscillator, the output of the first bias adder, and the output of the second and fourth detectors, and
second and third comparators each generate a detection signal when the outputs of the second and fourth detectors are larger than the output of the bias adder; The outputs of the sixth and seventh detectors are compared, and the output of the sixth and seventh detectors is compared with the output of the sixth and seventh detectors.
a signal detector comprising a fourth and a fifth comparator, each of which generates a detection signal when the output of the detector is large; and one or more of the second to fifth comparators of the signal detector. a trigger pulse generator that generates a trigger pulse when a detection signal is obtained; and a sixth detector that compares two outputs of each of the second, fourth, sixth, and seventh detectors.
~ a signal comparator consisting of an eleventh comparator; a quadrant determiner that determines the quadrant in which the target exists based on the comparison result of the signal comparator; A proximity fuze comprising first to fourth ignition circuits that each operate when it is determined that a target exists in a quadrant. (2) A variable attenuator is provided in the path from the directional coupler to the inputs of the first and second mixers, and the amount of attenuation of the variable attenuator is controlled by the output of the integrator via a function generator. A proximity fuse according to claim (1), characterized in that: