JPH06242236A - Frequency agility type radar beacon - Google Patents

Abstract

PURPOSE:To provide a frequency agility radar beacon in which a beacon pulse having the same frequency as that of a radar pulse is output to radar pulses having different frequencies even if the radar pulses are input during receiving of the radar pulse having a frequency f1. CONSTITUTION:Frequency values of frequencies f1, f2, f3 of radar pulses to be input are stored in reception frequency holders 11, 12, 13, levels are stored in memories 21, 22, 23, the frequency values are sent from the holders 11, 12, 13 to an equal frequency signal output unit 4 during a radar pulse period in response to the frequencies f1, f2, f3 by changeover switches 60, 61, and signals having the same frequencies as the frequency values to be input are output during a radar pulse, and input to a modulator 5. Levels of the frequencies f1, f2, f3 are input to a peak detector 7 and a level comparator 8 from the memories 21, 22, 23, the modulator 5 is turned ON at the time of a main lobe, and turned OFF at the time of a side lobe.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention, even if radar pulses of different frequencies are input during reception of radar pulses of frequency f ₁ , even if the accuracy of the circuit and the environmental conditions change, The present invention relates to a frequency agile radar beacon device capable of outputting a beacon pulse having the same frequency as a radar pulse.

[0002]

2. Description of the Related Art FIG. 4 is a block diagram of a main part of a conventional frequency agile radar beacon device.

As a frequency agile type radar beacon device capable of outputting a beacon pulse having the same frequency as the radar pulse even if the accuracy of the circuit is changed and the environmental conditions are changed, the present applicant has filed a patent on January 20, 1993. There is a radar beacon device applied for, which is as shown in FIG.

To explain the operation of FIG. 4, the radar signal pulse input from the receiver 32 is input to the frequency discriminator 1-1 through the changeover switch 64, and the discriminated frequency is A /
It is input to the D conversion unit 1-2, converted into a digital signal, and input to the reception signal holding circuit 11 via the changeover switch 63 to hold the frequency value.

The frequency value held in the received signal holding circuit 11 is sent to and held in the data holding circuit 41, is input to the D / A conversion section 37, becomes the voltage value of the analog signal, and is input to the voltage controlled oscillation section 36. A signal having a frequency suitable for the voltage is oscillated, input to the modulator 38, and modulated by the encoded signal.

When the frequency value is held in the reception signal holding circuit 11 and the voltage value of the analog signal is input to the voltage controlled oscillator 36, the controller 50 detects this and sends a control signal, and the changeover switch 64 and the changeover switch. 63 is the dotted line side.

Then, the signal modulated by the coded signal in the modulator 38 is input to the frequency discriminator 1-1 through the changeover switches 65 and 64, and the discriminated frequency signal is A The digital signal is converted into a digital signal by the / D converter 1-2, and the digital signal is input to the comparison circuit 30 to obtain the difference from the frequency value of the radar signal held in the received signal holding circuit 11.

It is desirable that the difference is 0 in the comparison circuit 30, but the accuracy of the D / A conversion unit 37 (the A / D conversion unit 1-2 outputs the radar signal and the output of the voltage control oscillation unit 36). The accuracy of the A / D converters 1-2 does not matter, and a difference occurs due to a change in the frequency of the voltage controlled oscillator 36 due to a change in environmental conditions such as temperature and power supply voltage.

In the comparison circuit 30, a difference obtained by subtracting the value of the frequency of the voltage controlled oscillator 36 from the value of the frequency of the radar signal held in the reception signal holding circuit 11 is added.
1 is added to the frequency value of the radar signal stored in the data holding circuit 41, the added value is stored in the data holding circuit 41 again, and is input to the D / A conversion unit 37, and the added value is added. The analog voltage corresponding to is output and applied to the voltage controlled oscillator 36.

Then, the output signal of the voltage controlled oscillator 36 is
The signal is input to the modulator 38, is modulated by the encoded signal, and is input to the frequency discriminator 1-1 via the changeover switch 65 and the changeover switch 64. The signal of the discriminated frequency is the A / D converter 1-2. Is converted into a digital signal by the comparison circuit 3
0, the difference with the frequency value of the radar signal held in the received signal holding circuit 11 is obtained, and the difference is added to the frequency value stored in the data holding circuit 41, and the added value is again held in the data holding circuit 41. And input to the D / A converter 37,
The comparison circuit 30 outputs the analog voltage corresponding to the added value and gives it to the voltage controlled oscillator 36.
Repeat until it is admitted.

When the comparison circuit 30 recognizes that the difference is 0, the control section 50 issues a control signal to change the switch 63.
Is the original solid line side, and the changeover switch 65 is the dotted line side for about 17 ms of the reception time of the signal of the main rope. , 65 are the original solid line side connections.

That is, even if the output frequency of the voltage controlled oscillator 36 is different from the frequency of the radar signal due to the accuracy of the circuit and changes in environmental conditions such as temperature and power supply voltage, the output of the voltage controlled oscillator 36 is different. Since the frequency is matched with the frequency of the radar signal and then output as the beacon signal for a predetermined time, the frequency of the beacon signal does not deviate from the frequency of the radar signal.

[0013]

However, the reception time of the signal of the main lobe of the frequency f ₁ of the main lobe is longer than that of the radar pulse even if the signal of the radar pulse of different frequency is input from another ship. Does not output a beacon signal that matches the frequency of the radar pulse of a different frequency, and there is a problem that it cannot service other ships.

According to the present invention, even if radar pulses of different frequencies are input during the reception time of the signal of the main lobe of frequency f ₁ , even if the accuracy of the circuit and the environmental conditions change, It is an object of the present invention to provide a frequency agile radar beacon device capable of outputting a beacon pulse having the same frequency as a radar pulse.

[0015]

FIG. 1 is a block diagram showing the principle of the present invention. As shown in FIG. 1, the frequency of the received radar pulse is discriminated and A / D converted into frequency data, and the frequency discriminating unit 2 and the first, second, third ... Reception frequency holding units 11, 12, 13 ... The frequency data conversion unit 1 to be input to, the frequency identification unit 2 that identifies the input frequency data and notifies the radar pulse period to the control unit 3, the level of the received radar pulse is identified, and the level data is Memory 2 for the first, second, third, ... radar pulse period
, 22, 23, ..., The level identification unit 6 to be input to the peak detection unit 7 and the level comparison unit 8 and the input frequency data are held for each frequency by the control of the control unit 3. The second, third, ... Reception frequency holding units 11, 1
, 2, and the first, second, third, etc. memories 2 for storing input level data at designated addresses
, 22, 23, ..., The same frequency signal output unit 4 that outputs the same frequency signal as the frequency of the radar pulse, and the code generation unit 9 that turns the modulation unit 5 on and off by the output of the level comparison unit 8, A modulator 5 which receives the output of the same frequency signal output unit 4 and turns on / off according to a code by a signal from the code generator 9, and a reception frequency holding unit 11 of the first, second, third ... , 12, 13, ..., And the first changeover switch 60 for switching the connection between the respective outputs of the same frequency signal output section 4 and the first, second, third ,.
1, 2, 23, ... Outputs and the peak detector 7
And a second switching connection with the input of the level comparison unit 8
Changeover switch 61, the peak detection unit 7 for comparing the level stored in each memory input via the second changeover switch 61 with the current input level, and returning the larger one to each memory for storage. The level stored in each memory inputted via the second changeover switch 61 is compared with the current input level to detect whether it is within a predetermined range or out of a predetermined range. The level comparator 8 which outputs a code from the generator 9 and outputs an off signal from the code generator 9 during the radar pulse period of the current input level when the value is out of the predetermined range, and f _{1 of} the first frequency data which is input _first. Is held in the first receiving frequency holding unit 11, and when the next input second frequency data is f ₂ different from the _first frequency data f ₁ , the second receiving frequency holding unit 12 is held. Hold and enter the next Frequency data is first, second frequency data f _1, f ₂ and at a different time than is the next third such is holding operation to the reception frequency holding unit 13, and input to the frequency data, the first, The first and second changeover switches 60 and 61 are set to hold the same frequency signal output unit 4 and the first, second, third, ... Reception frequencies according to the second, third, ... .., the peak detector 7, the level comparator 8, and the first, second, and
The frequencies stored in the third, ..., Memories 21, 22, 23, ... Respectively, and held in the first, second, third, ... Reception frequency holding units 11, 12, 13 ,. The data is input to the same frequency signal output unit 4 via the first changeover switch 60 for the radar pulse period, and the corresponding first, second, third memory 21, 22, 23 ,.・
・ Enter the address as an address, and the first, second, third
The level data stored in each of the memories 21, 22, 23, ... Are input to the peak detection unit 7 and the level comparison unit 8 via the second changeover switch 61 during the radar pulse period and the peaks are input. The output of the detection unit 7 is input to the first, second, third, ... Memories 21, 22, 23, ... And stored in the original address position. .

[0016]

According to the present invention, the received radar pulse is converted into frequency data by the frequency data conversion unit 1 and input to the frequency identification unit 2, and the radar pulse period is notified to the control unit 3.

Further, the received radar pulse has a level identification section 6
The level is identified at the radar pulse period, the first, second, and
It is input to the third memory 21, 22, 23, ..., The peak detector 7 and the level comparator 8.

The control unit 3 causes the first receiving frequency holding unit 11 to hold f ₁ of the first frequency data input first, and the second frequency data input next is the first frequency data. When f ₂ different from f ₁ is held in the next second reception frequency holding unit 12, when the next input third frequency data is different from the _first and _second frequency data f ₁ and f _2. Operates such that it is held by the third receiving frequency holding unit 13, and the frequency data to be input corresponds to the first, second, third, ...
The same frequency signal output unit 4 and the first, second, third
The reception frequency holding units 11, 12, 13, ... Are connected to each other, and the frequency data stored in the reception frequency holding unit is input to the same frequency signal output unit 4 during the radar pulse period. A signal having the same frequency as the frequency data is output and input to the modulator 5.

Further, the frequency data held in the first, second, third, ... Receiving frequency holding units 11, 12, 13, .. The corresponding first, second, third, ... Memories 21, 22, 23, ... Are input as addresses to store the level data from the level identification section 6.

Further, the second change-over switch 61 is responsive to the frequency data to be input, the peak detection section 7 and the level comparison section 8 and the first, second, third, ... Memories 21, 22, 2
3, ... Level data stored in the first, second, third, ... Memories 21, 22, 23, ..
Via the input to the peak detection unit 7 and the level comparison unit 8. In the peak detection unit 7, the level stored in the input memory is compared with the current input level and the larger one is returned to the memory for storage and input again. This is repeated for each radar pulse input of the same frequency, and the level stored in the input memory is compared with the current input level to detect whether it is within a predetermined range or out of the predetermined range. The code generator 9 outputs a code signal, and the modulator 5 modulates at the frequency of the frequency signal input from the same frequency signal output unit 4 in accordance with the code from the code generator 9 to output as a beacon signal. At this time, the off signal is output from the code generator 9 and the output from the modulator 5 is stopped during the radar pulse period of the current input level.

The same frequency signal output section 4 outputs a signal having the same frequency as the radar pulse even if the accuracy of the circuit and the environmental conditions change. That is, even if radar pulses of different frequencies are input during reception of the radar pulse of the frequency f ₁ of the main lobe, even if the accuracy of the circuit and the environmental conditions change, the radar pulse of the same frequency as the radar pulse is received. Beacon pulse can be output.

[0022]

FIG. 2 is a block diagram of an essential part of a frequency agile type radar beacon device according to an embodiment of the present invention, and FIG. 3 is a case where radar pulses of frequencies f ₁ and f _{2 according to} the embodiment of the present invention are input substantially at the same time. It is a figure which shows the beacon pulse of.

FIG. 2 shows the frequency f as shown in FIG.
_Even if radar pulses ₁ and f ₂ are input almost at the same time, as shown in FIG.
As shown in (B), a frequency agile radar beacon device capable of outputting beacon pulses of frequencies f ₁ and f ₂ is shown.

The radar pulse is usually several hundreds as shown in FIG.
It is transmitted with a period of several hundreds of μs and has a main lobe period.
The interval is several tens of ms. In the present invention, the accuracy of the circuit
Now, even if the environment changes, the same frequency as the radar pulse
The beacon pulse during the radar pulse period.
And at frequency f ₁, F₂Radar pulses are input almost simultaneously
Even if the frequency f₁, F₂Can output the beacon pulse of
It has become so.

In FIG. 2, the radar pulse emitted from the ship radar is received by the receiving unit 32 and is input to the distributing unit 33, and the distributed radar pulse is input to the frequency discriminating unit 1-1 and the detecting unit 34.

The frequency discriminating unit 1-1 discriminates the frequencies, and the A / D converting unit 1-2 produces a digital signal, which is input to the receiving frequency holding units 11 and 12 via the frequency discriminating unit 2 and the changeover switch 63.

The frequency identifying section 2 identifies whether the frequency is f ₁ or f ₂ from the received data and notifies the control section 3 of the radar pulse period. If the frequency of the pulse is f ₁ , the control unit 3 causes the reception frequency holding unit 11 to hold the pulse, and the frequency is f ₂
If the pulse is, the reception frequency holding unit 12 holds the pulse.

Then, the frequency data is stored in the data holding circuit 4
Held at 1, 42. Under the control of the control unit 3, the changeover switches 60 and 62 are set to the solid line side when the frequency data is f ₁ , the dotted line side when the frequency data is f ₂ , the changeover switch 63 is set to the dotted line side, and the changeover switch 66 is turned on. Comparison circuit 30,
Adder circuit 31, D / A converter 37, voltage controlled oscillator 3
6, a modulation unit 5, a changeover switch 66, a frequency discrimination unit 1-1, an A / D conversion unit 1-2, a changeover switch 63, a data holding unit 41 or 42 in the same loop as described in FIG. Then, the output frequency of the voltage controlled oscillator 36 is set to be the same as the input frequency data, the changeover switch 66 is turned off, and the changeover switch 63 is set to the solid line side to output a pulse having the same frequency as the radar pulse period and frequency data to the modulator 5. Input.

The detection unit 34 detects the radar pulse to be input, the level identification unit 6 identifies the level, and the memory 2
1, 22 and the peak detector 7 and the level comparator 8. At this time, the control unit 3 outputs the frequency data held in the reception frequency holding units 11 and 12 to the radar pulse period changeover switch 60 in accordance with the frequencies f ₁ and f ₂ to be input, and also responds to them respectively. Memory 21,2
2 is input as an address, and the level data from the level identification unit 6 is stored.

Further, the change-over switch 61 is connected to the peak detecting section 7 and the level comparing section 8 and the memories 21 and 22 in accordance with the inputted frequency data f ₁ and f ₂ , and the memories 21 and 22, respectively.
The level data stored in each of 22 is used for the radar pulse period,
The peak detection unit 7 and the level comparison unit 8 are input via the changeover switch 61. In the peak detection unit 7, the level stored in the input memory is compared with the current input level and the larger one is returned and stored in the memory. The input is repeated every time a radar pulse is input, and the level comparison unit 8
The level stored in the input memory is compared with the current input level to detect whether it is within 20 dB or not. When it is within 20 dB, it is within the main lobe. Therefore, the radar signal period of the current input level is generated by the code generator 9 from the code signal. Is output as a beacon signal having the same frequency as the radar pulse from the modulator 5, and when it is 20 dB or less, since it is a side lobe signal, the off signal is output from the code generator 9 during the radar pulse period of the current input level. The output from the modulator 5 is stopped.

That is, as shown in FIG. 3A, even if radar pulses of frequencies f ₁ and f ₂ are input almost at the same time,
As shown in (B), since beacon pulses of frequencies f ₁ and f ₂ can be output, it becomes possible to simultaneously service a plurality of ships.

In the above description, the case where radar pulses of two frequencies are input almost at the same time has been explained. However, even when radar pulses of different frequencies are input at the same time, the frequency can be considered in the same way. It is possible to configure an agile radar beacon device.

[0033]

As described above in detail, according to the present invention, even if radar pulses of different frequencies are input during reception of radar pulses of frequency f ₁ , the accuracy of the circuit and the environmental condition Even if there is a change, a beacon pulse having the same frequency as the radar pulse can be output, and there is an effect that a plurality of ships can be serviced simultaneously.

[Brief description of drawings]

FIG. 1 is a block diagram of the principle of the present invention,

FIG. 2 is a block diagram of a main part of a frequency agile radar beacon device according to an embodiment of the present invention,

FIG. 3 is a diagram showing a beacon pulse when radar pulses of frequencies f ₁ and f ₂ of the embodiment of the present invention are input substantially at the same time,

FIG. 4 is a block diagram of a main part of a conventional frequency agile radar beacon device.

[Explanation of symbols]

 1 is a frequency data conversion unit, 1-1 is a frequency discrimination unit, 1-2 is an A / D conversion unit, 2 is a frequency identification unit, 3,50 is a control unit, 4 is the same frequency signal output unit, and 5, 38 are Modulation section, 6 is a level identification section, 7 is a peak detection section, 8 is a level comparison section, 9 is a code generation section, 11, 12 and 13 are reception frequency holding sections, 21, 22 and 23 are memories, and 30 is a comparison circuit. , 31 is an adding circuit, 32 is a receiving unit, 33 is a distributing unit, 34 is a detecting unit, 35 is a transmitting unit, 36 is a voltage controlled oscillating unit, 37 is a D / A converting unit, 41 and 42 are data holding units, 60 Reference numerals 66 to 66 denote changeover switches.

Claims (1)

[Claims] 1. A frequency discriminating section (2) for discriminating the frequency of a received radar pulse and A / D converting it into frequency data.
And the first, second, third, ... Reception frequency holding units (11,
Frequency data conversion unit (1) to be input to 12, 13, ..., And a frequency identification unit (2) for identifying the input frequency data and notifying the radar pulse period to the control unit (3)
, The level of the received radar pulse is identified, and the level data is used for the radar pulse period, the first, second, third memory (21, 22, 23, ...), the peak detector (7) and The level identifying unit (6) to be input to the level comparing unit (8) and the input frequency data are held for each frequency under the control of the control unit (3).
., And the first, second, third, ... memories (21, 22, 23, ...) Which store the input level data at designated addresses.
.), The same frequency signal output unit (4) that outputs a signal at the same frequency as the radar pulse frequency, and a code generation unit (9) that turns on and off the modulation unit (5) by the output of the level comparison unit (8) A modulation section (5) which receives the output of the same frequency signal output section (4) and turns on / off in accordance with a signal from the code generation section (9), and the first, second, third.
The first changeover switch (60) for switching the connection between each of the outputs of the reception frequency holding units (11, 12, 13, ...) And the same frequency signal output unit (4), and the first and second ，
The outputs of the third memory (21, 22, 23, ...) And the peak detection section (7) and the level comparison section (8)
The second selector switch (6
1) and the peak detection unit (7) that compares the level stored in each memory input via the second changeover switch (61) with the current input level and returns the larger one to each memory. , The level stored in each memory input through the second changeover switch (61) is compared with the current input level to detect whether the level is within a predetermined range or out of a predetermined range. The level comparison unit (8) that outputs a code from the code generation unit (9) during a pulse period and outputs an off signal from the code generation unit (9) during the radar pulse period of the current input level when the value is out of a predetermined range, f ₁ is the first reception frequency holding unit of the first frequency data input (11) is held in, the frequency data is a second different from the frequency data f ₁ of the first entered then the frequency data f ₂ Then the second reception frequency holding unit (1 ) Is held in, first then entered frequency data, retention time of the second frequency data f _1, f ₂ different from the third frequency data in the third reception frequency holding unit of the following (13) The frequency data to be input or to be input is set to the first, second or third changeover switch (60, 61) according to the first, second, third, ...
The same frequency signal output unit (4) and the first, second, third,
.. connection with each of the reception frequency holding units (11, 12, 13, ...), the peak detection unit (7) and the level comparison unit (8), and the first, second, third, ... (21,2
2, 23, ...), and the first, second, third ... Reception frequency holding sections (11, 12, 13,
..) is input to the same frequency signal output unit (4) through the first changeover switch (60) during the radar pulse period, and the corresponding first, second, and Third memory (21, 22, 23, ...
・) As an address, and the first, second, third
.. level data stored in the memories (21, 22, 23, ...) Through the second changeover switch (61) during the radar pulse period, the peak detection section (7) and the level comparison section. Input to (8) and the peak detection section (7)
Output of each of the first, second, third ... (21,
22, 23, ...) and the control unit (3) for storing the original address position in the frequency agile radar beacon device.