JPH0720235A - Mono-pulse tracking apparatus - Google Patents

Abstract

PURPOSE:To make the suppressing of effect possible by a jamming electromagnetic wave to its minimum thereof by switching a feed forward type automatic gain control circuit and a feed back type automatic gain control circuit properly by an output of a pulse width detection circuit. CONSTITUTION:A pulse width of a mono pulse sum signal is detected with a pulse width detection circuit 15 connected to an output terminal T2 to which the mono pulse sum signal is outputted of a mono pulse comparator 2 linked to an antenna 1 which receives electromagnetic waves. It is judged from the pulse width whether or not the signal received is a jamming electromagnetic wave. As a result, when the signal received is the jamming electromagnetic wave, a feed forward automatic gain control circuit 13 connected to the output terminal T2 is switched, otherwise, a feed back automatic gain control circuit 9 is done with a switch 14 which is opened or closed by an output of the detection circuit 15. This makes the suppressing of damage of a tracking apparatus possible and the drop in accuracy of an angle error signal even when the jamming electromagnetic wave with a large power is received.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is for irradiating an electromagnetic wave to a target to be detected, receiving the electromagnetic wave reflected thereby, extracting necessary information from the received signal, and supplementing and tracking the target. The present invention relates to a monopulse tracking device.

[0002]

2. Description of the Related Art FIG. 4 is a diagram showing a conventional monopulse tracking device. In the figure, 1 is an antenna for receiving an electromagnetic wave reflected by a target, 2 is connected to this antenna 1, and its three output terminals T1. , T2, T3, respectively, and a monopulse comparator which outputs the monopulse difference signal to the output terminal T1.
The monopulse sum signal is output to the output terminal T2. Then, a monopulse difference signal is output to the output terminal T3. 3a, 4
a and 5a are output terminals T of the monopulse comparator 2
1, T2, and T3, which are first, second, and third delay lines respectively connected to T3, T3, and T3 to delay the monopulse sum signal and the monopulse difference signal, and have different delay times. 6 is the above three delay lines 3a, 4a, 5
With the output of a as an input, one monopulse sum signal and 2
Combiner for converting two monopulse difference signals into one channel, 7
Is a filter for removing unnecessary components, 8 is an amplifier, 9
Is a feedback type automatic gain control circuit (feed b) for optimally controlling the gain of the amplifier 8 with the output of the amplifier 8.
ack automatic gain contro
l circuit: hereinafter referred to as FBAGC circuit), 10 is an original 1 which is a pulse signal converted into one channel by the combiner 6.
The first power distributors 3b, 4b, 5b for distributing one monopulse sum signal and two monopulse difference signals are the above-mentioned first, second and third delay lines 3a, 4
a and 5a, the fourth delay line 3b is the same as the first delay line 3a, and the fifth delay line 4b is the same as the second delay line 4a. The delay line 5b is the same as the third delay line 5a. Reference numeral 11 is a second power distributor for distributing the monopulse sum signal output from the delay line 4b into two, and 12 is an output of the second power distributor 11 and output of the delay lines 3b and 5b. It is a phase detector that detects the phase difference from the difference signal and guides the angle error signal.

The conventional monopulse tracking device is constructed as described above, the electromagnetic wave reflected by the target is received by the antenna 1, the monopulse difference signal is output from the output end T1 of the monopulse comparator 2, and the monopulse sum signal is output from the output end T2. Further, the output terminal T3 outputs a monopulse difference signal. The respective monopulse signals are different by the first delay line 3a connected to the output end T1, the second delay line 4a connected to the output end T2, and the third delay line 5a connected to the output end T3. Delay time is given. Each monopulse signal that has passed through these delay lines 3a, 4a, 5a is converted into one channel by the combiner 6, the unnecessary components are removed by the filter 7, and the amplified by the amplifier 8. F with the output of the amplifier 8 as an input
The BAGC circuit 9 controls the optimum gain of the amplifier 8. In addition, in the first power divider 10 which receives the output of the amplifier 8, the same three inputs as those of the above-mentioned coupler 6
It is divided into one monopulse sum signal and two monopulse difference signals. The two monopulse difference signals are unified by the fourth and sixth delay lines 3b and 5b, and the monopulse sum signal is unified by the fifth delay line 4b. Delay is added. The output of the fifth delay line 4b is divided into two by the second power divider 11, and the phase detector 1
2, the monopulse difference signal output from the fourth and sixth delay lines 3b and 5b and the second power divider 1
The phase difference with the monopulse sum signal which is the output of 1 is detected,
Obtain the angle error signal.

[0004]

In the conventional monopulse tracking device as described above, the FBAGC circuit 9 is used so as to detect a very weak electromagnetic wave reflected by the target.
Since the gain of the amplifier 8 is optimized and amplified by the tracking device, the tracking device may be damaged or the angular error may be caused when the target itself and the jamming dedicated aircraft flying about the target receive a momentary high-power electromagnetic interference. There was a possibility that the accuracy of the signal would decrease, and it was necessary to improve this.

The present invention is intended to solve such a problem, and it is an object of the present invention to suppress damage to the tracking device and decrease in accuracy of the angle error signal when the monopulse tracking device is used in a strong jamming environment. .

[0006]

SUMMARY OF THE INVENTION A monopulse tracking device according to the present invention is a pulse width detection circuit for detecting a pulse width of a received electromagnetic wave and a feedforward type automatic circuit connected to an output terminal of a monopulse comparator for outputting a monopulse sum signal. Gain control circuit (feed forward)
(automatic gain control circuit: hereinafter referred to as FFAGC circuit), and a switch for switching to an appropriate automatic gain control circuit of the FFAGC circuit and the FFBAGC circuit by the output of the pulse width detection circuit.

Further, a peak power detection circuit and an FFA for detecting the peak power of the received electromagnetic wave, which is connected to the output end of the monopulse comparator which outputs the monopulse sum signal.
The output of the GC circuit and the peak power detection circuit is FFAGC.
A switch for switching to an appropriate automatic gain control circuit of the circuit and the FBAGC circuit is arranged.

Further, a pulse width detection circuit for detecting the pulse width of the received electromagnetic wave and a peak power detection circuit for detecting the peak power, which are connected to the output end of the monopulse comparator for outputting the monopulse sum signal, and the logical sum of these outputs is calculated. A desired logic circuit, an FFAGC circuit, and an output of the above logic circuit are provided with a switch for switching to an appropriate automatic gain control circuit of the FFAGC circuit and the FBAGC circuit.

[0009]

When the monopulse tracking device configured as described above is used to supplement or track a target, even if an electromagnetic wave of strong power is received momentarily, the electromagnetic wave is detected by the pulse width detection circuit or the peak power detection circuit. Detected and FFAG
Since the gain of the amplifier can be lowered in advance by the C circuit, the monopulse tracking device can be supplemented and tracked with the target without being damaged and continuing.

[0010]

【Example】

Example 1. FIG. 1 is a block diagram showing an embodiment of the present invention, in which 1 is an antenna, 2 is a monopulse comparator,
3a is a first delay line, 4a is a second delay line, 5a is a third delay line, 6 is a coupler, 7 is a filter, 8 is an amplifier, 9 is an FBAGC circuit, and 10 is a first power distributor. 3b is a first delay line, 4b is a second delay line, 5b is a third delay line,
11 is a second power divider, 12 is a phase detector, 13 is connected to the output terminal T2 of the monopulse comparator 2,
An FFAGC circuit for controlling the gain of the amplifier 8 with a monopulse sum signal output from the output terminal T2, a switch 14 for switching between the FBAGC circuit 9 and the FFAGC circuit 13, and 15 for an output terminal T2 of the monopulse comparator 2. This is a pulse width detection circuit that is connected and detects the pulse width of the monopulse sum signal output from the output terminal T2, and controls the opening and closing of the switch 14 by this output. It should be noted that 1 to 12 in the figure are exactly the same as those of the conventional device.

In the monopulse tracking device configured as described above, the output terminal T2 of the monopulse comparator 2
The pulse width detection circuit 15 connected to detects the pulse width of the monopulse sum signal, and based on this, it is determined whether the received signal is an interfering electromagnetic wave. As a result, if the received signal is an interfering electromagnetic wave, the FFAGC circuit 13 connected to the output terminal T2 of the monopulse comparator 2
FB connected to the output terminal of the amplifier 8 if it is not an interfering electromagnetic wave
The AGC circuit 9 is switched by the switch 14 which opens and closes by the output of the pulse width detection circuit 15. Therefore,
Damage to the tracking device and deterioration of the accuracy of the angle error signal can be suppressed even if a high-power electromagnetic wave is received.

Example 2. In FIG. 2, the peak power detection circuit 16 connected to the output terminal T2 of the monopulse comparator 2 detects the peak power of the monopulse sum signal, and based on this, it is determined whether or not the received signal is an interfering electromagnetic wave. . As a result, if the received signal is an interfering electromagnetic wave, F connected to the output end T2 of the monopulse comparator 2 will be described.
If the FAGC circuit 13 is not an interfering electromagnetic wave, the FBAGC circuit 9 connected to the output end of the amplifier 8 can be switched by the switch 14 which is opened / closed by the output of the peak power width detection circuit 16, and the same operation as that of the first embodiment is expected. it can.

Embodiment 3. In FIG. 3, the pulse width detection circuit 15 and the peak power detection circuit 16 connected to the output end T2 of the monopulse comparator 2 determine whether or not the monopulse sum signal output from the output end T2 is an interfering electromagnetic wave. To be done. The logical operation of these outputs is performed in the logic circuit 17 which receives the outputs of the pulse width detection circuit 15 and the peak power detection circuit 16, and one of the pulse width detection circuit 15 and the peak power detection circuit 16 is operated. If it is recognized that the electromagnetic wave received at is an interfering electromagnetic wave, the output terminal T2 of the monopulse comparator 2 is controlled by the switch 14 which receives the output of the logic circuit 17 as an input.
The FFAGC circuit 13 connected to the
The gain of the amplifier 8 is controlled by the AGC circuit 13. On the other hand, if it is determined that the electromagnetic waves received by the pulse width detection circuit 15 and the peak power detection circuit 16 are not interfering electromagnetic waves, the switch 14 selects the FBAGC circuit 9 which receives the output of the amplifier 8 as an input, and this FBAGC circuit is selected. Since the gain of the amplifier 8 is controlled by 9, the same operation as that of the first embodiment can be expected.

[0014]

Since the present invention is configured as described above, the FFAGC circuit proactively optimizes the gain before amplifying the received signal even if a large power interfering electromagnetic wave is received momentarily. Can be set to, and the effect of the electromagnetic interference can be minimized.

[Brief description of drawings]

FIG. 1 is a block diagram showing a first embodiment of the present invention.

FIG. 2 is a block diagram showing a second embodiment of the present invention.

FIG. 3 is a block diagram showing a third embodiment of the present invention.

FIG. 4 is a block diagram showing an embodiment of a conventional device.

[Explanation of symbols]

 1 Antenna 2 Monopulse Comparator 3 Delay Line 4 Delay Line 5 Delay Line 6 Coupler 7 Filter 8 Amplifier 9 FBAGC Circuit 10 First Power Distributor 11 Second Power Distributor 12 Phase Detector 13 FFAGC Circuit 14 Switch 15 Pulse Width Detection circuit 16 Peak power detection circuit 17 Logic circuit

Claims (3)

[Claims] 1. An antenna for receiving an electromagnetic wave reflected from a detection target, and a monopulse sum signal that is connected to this antenna and outputs to one of three output ends,
A monopulse comparator that outputs a monopulse difference signal to the remaining two output terminals, and two output terminals that output the monopulse difference signal among the three output terminals, respectively, and delay the monopulse difference signal by a predetermined time. And a third delay line, which is connected to the output terminal from which the sum signal is output and which is connected to the second delay line for delaying the monopulse sum signal by a certain time and the first to third delay lines, and outputs them. As an input, a combiner for converting to one channel, a filter for removing an unnecessary component from the output of this combiner, an amplifier for amplifying the output of this filter, and an input terminal of the second delay line, which are connected to the monopulse sum. A feedforward automatic gain control circuit for controlling the gain of the amplifier by a signal and an input terminal of the second delay line A pulse width detection circuit for detecting the pulse width of the monopulse sum signal, a feedback type automatic gain control circuit connected to the output end of the amplifier and controlling the gain of the amplifier with the output of this amplifier, and the pulse width detection circuit A switch for switching between the output of the feedforward type automatic gain control circuit and the output of the feedback type automatic gain control circuit by the output, and the output of the amplifier is divided into two original monopulse difference signals and one monopulse sum signal. The first power distributor and the two output terminals that output two monopulse difference signals out of the three outputs of the first power distributor are respectively connected to the first power distributor.
And the third and first delay lines that unify the delay time provided by the third delay line with the other outputs of the first power distributor, and the third power line of the first power distributor.
A second delay line connected to the output end from which one of the two outputs outputs a monopulse sum signal and unifying the delay time provided by the second delay line with the other outputs of the first power distributor. And a second power distributor which receives the output of the second delay line as an input and distributes a monopulse signal to two outputs, and outputs of the third and first delay lines and the second power distributor. A monopulse tracking device, which is configured by a phase detector that receives an output of the input and obtains an angle error. 2. A feed-forward type automatic gain control circuit connected to an input terminal of a second delay line for controlling the gain of the amplifier with a monopulse sum signal, and a feedback type automatic gain control circuit for controlling the gain of the amplifier with the output of the amplifier. The monopulse tracking device according to claim 1, further comprising a peak power detection circuit that controls a switch that switches between and. 3. A pulse width detection circuit connected to an input terminal of a second delay line for detecting the pulse width of a monopulse sum signal, a peak power detection circuit for detecting peak power, and an output of these, and a monopulse A logic circuit for controlling a switch for switching between a feedforward type automatic gain control circuit for controlling the gain of the amplifier by the sum signal and a feedback type automatic gain control circuit for controlling the gain of the amplifier by the output of the amplifier. Item 1. A monopulse tracking device according to item 1.