RU2498338C2 - Device for controlling ranging channel of radar systems - Google Patents

Abstract

FIELD: radio engineering, communication.

SUBSTANCE: device for controlling the ranging channel of radar systems has a UHF unit, a communication line, a horn antenna, a Doppler frequency synthesiser, a time delay device, a detector section, a multiplexer control bus, a switch, the common lead of which is connected to the pulse input of the time delay device, an AND element, the output of which is connected to the normally open contact of the switch, and the first input of the AND element is connected to the normally closed contact of the switch, a binary counter, the input of which is connected to the trigger pulse input of the transmitter and to the normally closed contact of the switch, a decoder, the group of inputs of which is connected to the group of outputs of the binary counter, a low-pass filter, the input of which is connected to the output of the detector section, and a time interval measuring device, the STOP input of which is connected to the output of the low-pass filter, the control inputs/outputs of the time interval measuring device are connected to the multiplexer control bus, the output of the decoder is connected to the second input of the AND element, the START input of the time interval measuring device and the clock output.

EFFECT: broader functional capabilities by providing both visual and automatic self-control of the disclosed device.

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Description

The present invention relates to the field of radar and can be used in instrumentation Doppler radar systems with a rangefinder channel.

Known radar target simulator containing a microwave module, a communication line, a horn antenna, a group of keys, two reprogrammable read-only memory devices (ROM), a multiplex bus interface, a Doppler frequency synthesizer, a multiplex control bus and a multiplying digital-to-analog converter [RF patent No. 2267798, cl. G01S 7/40, 2004].

This device allows you to test Doppler radar systems, but does not provide control of the rangefinder channel.

Also known is automated control equipment selected as a prototype, comprising a microwave unit, the microwave input of which is the input of the microwave equipment, a communication line whose input is connected to the output of the microwave unit, a horn antenna connected to the first output of the communication line, a Doppler frequency synthesizer module the output of which is connected to the amplitude modulation input of the microwave unit, a time delay module, the control input of which is connected to the output of the Doppler frequency synthesizer module, the pulse input of the time module the delay is the input of the transmitter start pulses and is connected to the first control output of the equipment, the output of the time delay module is connected to the pulse modulation input of the microwave unit and to the second control output of the equipment, the detector section, the input of which is connected to the second output of the communication line, and the output is the third control output equipment, and a multiplex control bus connected to the control inputs and outputs of the Doppler frequency synthesizer module, time delay module, and microwave unit [Automation naya test equipment (AKPA) AGSK.461271.216 Operating Instructions, MRI of "AGAT", 2010].

This equipment allows you to test Doppler radar systems with a rangefinder channel.

The disadvantage of the equipment is the inability to control the delay value of the transmitter start pulses. The equipment allows using an oscilloscope to control the oscillograms of the input pulses of the transmitter start (at the first control output) and the delayed pulses (at the second and third control outputs). However, with delays greater than the period of transmitter start-up pulses, which occurs in real equipment (the period of transmitter start-up pulses is several microseconds, and the maximum delay is several hundred microseconds), it is impossible to determine the true delay from oscillograms or using any other devices, determine only the remainder of dividing the delay by the period of the transmitter start pulses.

The purpose of the invention is the expansion of the functionality of the monitoring device of the rangefinder channel of radar systems by introducing the function of visual and automated self-monitoring.

This goal is achieved due to the fact that in the monitoring device of the rangefinder channel of radar systems, containing a microwave unit, the microwave input of which is the input of the microwave device, a communication line, the input of which is connected to the output of the microwave unit, a horn antenna connected to the first output of the communication line, a synthesizer Doppler frequencies, the output of which is connected to the input of the amplitude modulation of the microwave unit, a time delay device, the control input of which is connected to the output of the Doppler frequency synthesizer, the pulse input of the device this delay is connected to the first control output, and the output of the time delay device is connected to the pulse modulation input of the microwave unit and to the second control output, the detector section, the input of which is connected to the second output of the communication line, and the output is the third control output, and a multiplex control bus, connected to the inputs and outputs of the control of the Doppler frequency synthesizer, the time delay device and the microwave unit, a switch is introduced, the general output of which is connected to the pulse input of the device delay, element And, the output of which is connected to a normally open contact of the switch, and the first input of element AND is connected to a normally closed contact of the switch, a binary counter whose input is connected to the input of the start pulses of the transmitter of the device and with the normally closed contact of the switch, decoder, group of inputs which is connected to the group of outputs of the binary counter, a low-pass filter, the input of which is connected to the output of the detector section, and a time interval meter, whose STOP input is connected n to the output of the lowpass filter and the input-output control slots meter connected to the multiplex control bus, the decoder output is connected to the second input of AND gate, to the input of the START measuring time intervals and to the output of the synchronization device.

Figure 1 shows a block diagram of a device for monitoring the rangefinder channel of radar systems, which includes:

1 - microwave input;

2 - input pulses start the transmitter;

3 - microwave unit;

4 - communication line;

5 - horn antenna;

6 - Doppler frequency synthesizer;

7 - time delay device;

8 - detector section;

9 - multiplex control bus;

10 - switch;

11 - low-pass filter;

12 - element And;

13 - meter time intervals;

14 - binary counter;

15 - decoder;

16 ... 18 - the first, second and third control outputs;

19 - synchronization output.

The input of the microwave device 1 is connected to the input of the microwave unit microwave 3, the output of the microwave unit 3 is connected to the input of the communication line 4, the first output of which is connected to the horn antenna 5, and the second to the input of the detector section 8, the output of which is connected to the input of the low-pass filter 11 and with the third control output 18. The output of the Doppler frequency synthesizer 6 is connected to the amplitude modulation (AM) input of the microwave unit 3 and to the control input of the time delay device 7, the output of which is connected to the pulse modulation (IM) input of the microwave unit 3 and to the second control output 17. In control outputs of the microwave unit 3, the Doppler frequency synthesizer 6, the time delay device 7 and the time interval meter 13 are connected to the multiplex control bus 9. The pulse input of the time delay device 7 is connected to the first control output 16 and to the general output of the switch 10, normally open the contact of which is connected to the output of the And 12 element, and the normally closed contact of the switch 10 is connected to the first input of the And 12 element, with the input of the binary counter 14 and with the input of the start pulses of the transmitter 2. Group in moves the binary counter 14 is connected to a group of inputs of the decoder 15, whose output is connected to a second input of AND gate 12, exit 19 and the synchronization with the input of the START meter slots 13, STOP input of which is connected to the output of the lowpass filter 11.

The microwave unit 3 provides:

- frequency shift of the input microwave signal by the value of the Doppler frequency of the signal fed to the input AM from the Doppler frequency synthesizer 6;

- pulse modulation of the microwave signal by pulses arriving at the input of the IM from the device time delay 7;

- setting the output power by a digital signal supplied to the control inputs / outputs from the multiplex control bus 9.

The first output of the communication line 4 provides the transmission of the microwave signal from the microwave unit 3 to the horn antenna 5, the second is connected to the input of the detector section 8.

A horn antenna 5 emits a microwave signal simulating a signal reflected from a target.

The Doppler frequency synthesizer 6 generates a harmonic signal with a Doppler frequency. The frequency and signal level are set by a digital signal supplied to the control inputs and outputs of the Doppler frequency synthesizer 6 from the multiplex control bus 9.

The time delay device 7 provides a delay of the pulses received at the pulse input. The magnitude of the delay can be controlled by the frequency of the signal received at the control input — the rate of change in the delay is proportional to the frequency of the control signal (Doppler frequency), which allows you to simulate a moving target. The initial value of the delay (range to the target) is set by a digital signal fed to the control inputs / outputs of the time delay device 7 from the multiplex control bus 9.

The detector section 8 detects the microwave signal in order to obtain a pulse signal (similar to the pulses supplied to the pulse modulation input of the microwave unit 3) to control it with an oscilloscope.

The multiplex control bus 9 provides control of the parameters of the microwave unit 3, the Doppler frequency synthesizer 6 and the time delay device 7 with a digital signal received on the bus 9 from the control computer, as well as the transmission of the measured values of the pulse delays by the time interval meter 13 to the control computer.

The switch 10 provides the inclusion of the control mode of the magnitude of the delay pulses. In Fig.1, it is shown in the position when this mode is disabled.

The time interval meter 13 provides a measurement of the time interval between input pulses arriving at the START and STOP inputs, displaying the measurement results on digital indicators and transmitting the measured values through the multiplex control bus 9 to the control computer. As a meter of time intervals 13, an electronically counted frequency meter can be used.

Binary counter 14 is designed to divide the frequency of the input pulses. The capacity of the counter N is determined based on the fact that the period of the output pulses in the high order is not less than the maximum delay of the transmitter start pulses, and can be calculated by the formula:

,

,

where T _ass - the maximum delay time of the transmitter start pulses;

T _ISP - the minimum period of the pulses of the start of the transmitter.

The decoder 15 decrypts the output signals of the binary counter 14 and generates output pulses with a repetition period equal to the period of the output pulses of the binary counter 14 in the high order and a low level duration (log 0) corresponding to four periods of the input pulses of the binary counter 14.

The device operates as follows.

A continuous microwave signal is fed to microwave input 1 from a controlled radar system, which is transmitted to a microwave unit 3, where its frequency is shifted by the frequency of the Doppler signal fed to the input of the microwave unit 3 from a Doppler frequency synthesizer 6. This simulates a reflected signal from a moving targets (target speed is proportional to Doppler frequency). Next, the signal in the microwave unit 3 is subjected to pulse modulation by pulses arriving at the input of the microwave unit 3 from the output of the time delay device 7, to the pulse input of which through the switch 10 and input 2 (in the off mode of monitoring the value of the pulse delay) the transmitter starts from the controlled radar system. This simulates the delay of the signal reflected from the target, which determines the range of the target in the rangefinder channel of the radar system. Then, in the microwave unit 3, the signal power level is set by a digital signal supplied to the control inputs and outputs from the multiplex control bus 9.

The parameters of the Doppler frequency synthesizer signals 6 (frequency, amplitude), time delay device 7 (initial delay), and power level are set by a digital signal transmitted from the host computer via the multiplex control bus 9.

From the output of the microwave unit 3, the signal is transmitted through the communication line 4 to the horn antenna 5, near which there is a controlled radar system that receives a signal from the horn antenna. Thus, this device provides a simulation of the signal reflected from the target, the processing of which by a controlled radar system can be used to judge its performance and parameters.

To control the correct functioning of the monitoring device of the rangefinder channel of radar systems, it has three monitoring outputs 16 ... 18, on which using the oscilloscope you can monitor the following signals:

- at the first output 16, the start pulses of the transmitter at the input of the time delay device 7;

- at the second output 17 - delayed pulses of the start of the transmitter at the output of the time delay device 7;

- at the third output 18 - the envelope of the microwave signal at the output 2 of the communication line 4 (this signal is similar in shape to the signal at the second output 17).

In the off mode of monitoring the value of the delay of the pulses (the position of the switch 10 in this mode is shown in Fig. 1), when the delay values of the transmitter trigger pulses are more than the period of their repetition, it is impossible to determine the true delay value from the oscillograms, i.e. there is no control of the transmitter trigger pulse delay value, which the main parameter when checking the rangefinder channel of radar systems.

In the switched-on mode of monitoring the magnitude of the pulse delay to the pulse input of the pulse delay device 7, the signal comes from the output of element And 12 and is a packet of pulses with a repetition period of packs of at least the maximum pulse delay and a pause between the packets equal to four periods of the transmitter start pulses. Such a signal is generated using the binary counter 14, the decoder 15, the descriptions of which are given above, and the element And 12. Their operation is illustrated by the oscillograms shown in figure 2. As can be seen in figure 2, using a two-beam oscilloscope, you can determine the delay value of the start-up pulses of the transmitter T _back . For stable display of the oscillograms on the oscilloscope screen from the output of the decoder 15, the signal is supplied to the synchronization output 19, to which the synchronization input of the oscilloscope is connected.

In addition, the delay value is displayed by digital indicators of the time interval meter 13, to the START input of which pulses are received from the output of the decoder 15 (plot B in figure 2), and to the STOP input - from the output of the low-pass filter 11 (plot D in figure 2 ) The measured values of the pulse delays are also transmitted through the inputs and outputs of the time interval meter 13 and the multiplex control bus 9 to the control computer.

The use of a time interval meter 13 makes it possible to measure the delay of pulses in real time in the mode of changing the delay value, which is almost impossible to do using an oscilloscope, since in this mode the oscillogram of the delayed pulses will move around the oscilloscope screen. The transfer of the measured values of the pulse delays to the control computer allows you to automate the process of self-monitoring of the proposed device, as well as to provide a more accurate check of the rangefinder channel of radar systems in dynamic modes, since the control computer can in real time process the delay values of the transmitter start pulses generated by the proposed device, and calculated range values to the target by a controlled radar system, the information from which is fed to the control computer.

Thus, introducing into the known device a switch, an AND element, a binary counter, a decoder, a low-pass filter and a time interval meter with the indicated connections allows both visual and automated self-monitoring of the proposed device and, thus, expanding the functionality of the range-finding channel monitoring device radar systems, as well as provide a more accurate check of the controlled radar system in dynamic modes.

Claims (1)

A monitoring device for the rangefinder channel of radar systems, containing a microwave unit, the microwave input of which is the input of the microwave device, a communication line whose input is connected to the output of the microwave unit, a horn antenna connected to the first output of the communication line, a Doppler frequency synthesizer, the output of which is connected to the amplitude input modulation of the microwave unit, a time delay device, the control input of which is connected to the output of the Doppler frequency synthesizer, the pulse input of the time delay device is connected to the first control at the output, and the output of the time delay device is connected to the pulse modulation input of the microwave unit and to the second control output, the detector section, the input of which is connected to the second output of the communication line, and the output is the third control output, and a multiplex control bus connected to the inputs and outputs control of the Doppler frequency synthesizer, time delay device and microwave unit, while setting the output power in the microwave unit is provided by a digital signal fed to the control inputs / outputs of the microwave unit with п a multiplex control bus, characterized in that a switch is additionally introduced into it, the common output of which is connected to a pulse input of a time delay device, an And element, the output of which is connected to a normally open contact of the switch, and the first input of the And element is connected to a normally closed switch contact, binary a counter, the input of which is connected to the input of the start pulses of the transmitter and with the normally closed contact of the switch, a decoder, the group of inputs of which is connected to the group of outputs of two counter, a low-pass filter, the input of which is connected to the output of the detector section, and a time interval meter, the STOP input of which is connected to the output of the low-pass filter, the control inputs and outputs of the time interval meter are connected to the multiplex control bus, the decoder output is connected to the second input of the element And, to the START input of the time interval meter and to the synchronization output.

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