JPH0440387A - Continuous wave detecting circuit and system using same - Google Patents

Abstract

PURPOSE:To process and display even a pulse wave and a continuous wave by passing a pulse wave through a switching circuit as it is when the pulse wave is received, and generating a trigger pulse and applying it to the switching circuit when the continuous wave is received. CONSTITUTION:An input signal is divided 10 into two, one is inputted to the continuous wave detecting circuit 11, and the other is inputted to the switching circuit 18. The input signal of the circuit 11 is detected 12 and divided into two, which are inputted to a pulse generating circuit 15 and a counting circuit 13. When the input signal is the pulse wave, the H-level signal from the circuit 15 is passed through a gate circuit 17 to turn on the circuit 18, which passes the input pulse as it is. At the rise of the output from the detecting circuit 12, on the other hand, a counting circuit 13 counts a clock signal and when the counted value 13 reaches a set value A, a comparing circuit 14 outputs a pulse and a pulse generating circuit 16 outputs a trigger pulse, with which the circuit 17 is switched to control the circuit 18, and thus pulse modulation is imposed and the circuit 18 outputs a pulse signal. Thus, even when the continuous wave is received, the signal processing is enabled.

Description

[Detailed Description of the Invention] [Summary] The purpose of the present invention is to provide a circuit that performs signal processing by pulse modulating the received radio waves when a continuous wave is received, regarding a signal processor used in radio wave application equipment. A first pulse forming circuit that forms a pulse wave from a signal, a counting circuit that counts by hitting the input signal with a clock signal, and a count value of the counting circuit and a set value are compared, and the count result is determined as follows. A comparison circuit that sends out a pulse signal when the value is greater than a set value, a second pulse formation circuit that converts the output of the comparison circuit into a trigger signal, and from the first pulse formation circuit and the second pulse formation circuit. Input the output of
A gate circuit is provided which performs a switching operation to pass the signal from the first pulse forming circuit when the input signal is a pulse wave, and to pass the signal from the second pulse forming circuit when the input signal is a continuous wave. The switching circuit is configured to be controlled by the output of the circuit to output a pulse signal.

Further, the continuous wave detection circuit is used in a receiving system of a monitoring radar or the like, and is configured to enable signal processing and display of both pulse waves and continuous waves.

[Industrial application field]

The present invention relates to a signal processing circuit used in radio wave application equipment.

[Conventional technology]

FIG. 3 is a diagram showing a circuit of a conventional embodiment, and shows a direction finding display system. Further, FIG. 4 is a diagram showing a circuit of another conventional embodiment, and shows a repetition frequency analysis system. Note that FIG. 5 is a diagram showing waveforms of pulse waves and continuous waves. Further, in FIG. 3, 31 is an amplitude control circuit, 32 is a sawtooth wave generation circuit, 33 is a direction finding display generator, 34 is a video amplifier circuit, and 35 is a display. In addition, in Figure 4, 41 is JK-F.
F circuit, 42 is the first counting circuit, 43 is the second counting circuit, 4
4 is a clock generation circuit.

In FIG. 3, a video-processed pulsed video signal is input to an amplitude control circuit 31, and a sawtooth wave generation circuit 3
2 is generated, and when the video amplitude is large, the pulse width is large, and when the video amplitude is small, the pulse width is small. Send to 33. Note that the direction finding display generator 33 receives a direction signal from, for example, an encoder of a direction motor included in a surveillance radar (not shown), and only when the video signal and the direction signal match are matched. Sends out the input video signal.

This sent video signal is then transmitted to the video amplifier circuit 3.
The signal is amplified by step 4, brightness-modulated, and displayed on the display 35 in PPI.

Further, FIG. 4 shows a circuit for analyzing the repetition frequency of an input received signal. The pulsed received signal is input to the JK-FF circuit 41 whose J terminal and terminal are set to the "old gh' level of the DC voltage Vs.

This JK-FF circuit 41 is a J-operated flip-flop circuit, and each time a pulse-shaped reception signal is input, the output terminals Q and Q output a FF circuit whose phases are mutually inverted and whose period coincides with that of the repetition frequency. The first enable and the second enable are sent. The first counting circuit 42 and the second counting circuit are driven by the clock output from the clock generating circuit 44 to enable the first enable or the second enable.
The first counting circuit 42 starts the counting operation at the timing of the "old gh" level of the first enable, and sends out the PRF analysis data A by counting the number of clocks during the "old gh" level of the first enable. counts the number of clocks during the "old gh level" of the second enable during the pause period of the first counting circuit 42, and sends out the PRF analysis data B. Then, the pulse interval is analyzed from this PRF analysis data A and PRF analysis data B.

As mentioned above, for example, the signal processing system of a surveillance radar processes the pulse wave (a) of the pulse wave (a) and continuous wave (b) waveforms shown in FIG. ) signal processing was performed by generating a trigger at the rise of a pulse wave. However, even if an attempt is made to process the continuous wave shown in FIG. 5(b) using, for example, the circuit shown in FIG. 3 or 4, a trigger cannot be generated because it is a continuous wave. Therefore, in order to process the signal, it is necessary to generate a trigger.

[Problem to be solved by the invention]

Therefore, there is a problem in that signal processing is possible with pulse waves, but not with continuous waves.

An object of the present invention is to provide a circuit that performs signal processing by pulse-modulating a received radio wave when a continuous wave is received.

[Means for solving problems]

The present invention comprises a first pulse forming circuit 15 that forms a pulse wave from a pulse wave input signal, a counting circuit 13 that counts by hitting the input signal with a clock signal, and a count value of the counting circuit 13. a comparison circuit 14 that compares the count result with a set value and sends out a pulse signal when the count result is greater than the set value; a second pulse forming circuit 16 that converts the output of the comparison circuit 14 into a trigger signal; The outputs of the first pulse forming circuit 15 and the second pulse forming circuit 16 are respectively input, and when the input signal is a pulse wave, the signal from the first pulse forming circuit 15 is passed through, and when the input signal is a continuous wave, the signal is passed through. A gate circuit 17 that performs a switching operation so as to pass a signal from the second pulse forming circuit 16 is provided, and the switching circuit 18 is controlled by the output of the gate circuit 17 to output a pulse signal.

Further, the continuous wave detection circuit is used in a receiving system of a monitoring radar or the like, and is configured to enable signal processing and display of both pulse waves and continuous waves.

[For production]

In the present invention, as shown in FIG.
4 is used to count the time width of the input signal, and if the count value exceeds the set value, it is determined that it is a continuous wave, and when a pulse wave is received, it is passed through the switching circuit 18 as it is, and the continuous wave is In this case, the second pulse forming circuit 16 generates a trigger pulse, and the trigger pulse is applied to the switching circuit 18 via the gate circuit 17.

Therefore, this pulse wave or trigger pulse is switched to the switching circuit 1.
By turning on and off in addition to 8, a pulse wave is generated, and even when a continuous wave is received, it is possible to process the received signal.

〔Example〕

FIG. 1 is a diagram showing a continuous wave detection circuit configuration of the present invention,
FIG. 2 is a diagram showing an example of the use of the continuous wave detection circuit of the present invention. In FIG. 1, 10 is a power distribution circuit, 11 is a continuous wave detection circuit, a detection circuit 12, a counting circuit 13, a comparison circuit 14, a first pulse forming circuit 15, a second pulse forming circuit 16, and a gate circuit. 17 and a switching circuit 18. In FIG. 2, 11 is a continuous wave detection circuit, 21 is a receiving antenna, 22 is a microwave circuit, 23 is a power distribution circuit, 24 is a pin switch, 25 is a detection device, 26
27 is a signal processor, 27 is a video processor, and 28 is a display device. The received radio frequency input signal is divided into two by the power distribution circuit 10, for example, and one part is inputted to the continuous wave detection circuit 11, and the other part is inputted to the switching circuit 18. The input of the continuous wave detection circuit 11 is detected by the detection circuit 12 and then divided into two parts, which are input to the first pulse forming circuit 15 and the counting circuit 13.

When a pulse wave is input, the first pulse forming circuit 15 always outputs the "old gh" level, and the "old gh" level signal passes through the gate circuit 17 and makes the switching circuit 18 conductive, thus making the switching circuit 18 conductive. 18 input pulses pass through as is.

On the other hand, when the output from the detection circuit 12 rises, the counting circuit 13 becomes enabled and starts counting the clock signal, and when the count data B of the counting circuit 13 exceeds the set value A, a pulse is output from the comparator circuit 14. The pulse is output and hits the second pulse forming circuit 16 to output a pulse, and the pulse from the second pulse forming circuit 16 switches the gate circuit 17 and controls the switching circuit 18 to apply pulse modulation.
The switching circuit 18 sends out a pulse-shaped output signal.

Furthermore, in FIG. 2, the microwave received by the receiving antenna 21 undergoes signal processing in the microwave circuit 22, and then the received power is divided into two by the power distribution circuit 23, and one side is input to the continuous wave detection circuit 11. and input the other to the pin switch 24. If the received wave is a pulse wave, the received signal passes through the pin switch 24 as is. In addition, if the input signal continues for a certain period of time, continuous wave detection circuit 1
1 counts the continuous time and outputs a pulse-like trigger;
Therefore, a pulse signal is sent out from the pin switch 24.

The output of the pin switch 24 is subjected to, for example, a frequency analysis of a microwave reception signal by a detection device 25, and a PRF analysis by a signal processor 26. Further, the video processor 27 performs sidelobe suppression processing, for example, and converts the signal into a luminance signal, which is displayed on the display 28 in PPI.

〔Effect of the invention〕

As is clear from the above description, according to the present invention, signal processing and display are possible whether the received radio waves are pulse waves or continuous waves.

16 is a second pulse forming circuit; 17 is a gate circuit; 18 is a switching circuit; shows.

[Brief explanation of drawings]

Fig. 1 is a diagram showing the circuit configuration of the present invention, Fig. 2 is a diagram showing an example of the use of the continuous wave detection circuit of the present invention, Fig. 3 is a diagram showing a circuit of a conventional embodiment, and Fig. 4 is a diagram showing a circuit configuration of the present invention. 5 is a diagram showing a circuit of another conventional embodiment, and FIG. 5 is a diagram showing waveforms of pulse waves and continuous waves. In the figure, 10 is a power distribution circuit, 11 is a continuous wave detection circuit, 12 is a detection circuit, 13 is a counting circuit, 14 is a comparison circuit, 15 is a first pulse forming circuit, and 15 is a first pulse forming circuit. [Fig.
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fi Fig. 5

Claims (2)

[Claims] (1) A first pulse forming circuit (15) that forms a pulse wave from a pulse wave input signal, a counting circuit (13) that performs counting by hitting the input signal with a clock signal, and the counting circuit (13) ) and the set value,
a comparison circuit (14) that sends out a pulse signal when the count result is greater than the set value; a second pulse forming circuit (16) that converts the output of the comparison circuit (14) into a trigger signal; The outputs from the first pulse forming circuit (15) and the second pulse forming circuit (16) are respectively input, and when the input signal is a pulse wave, the output from the first pulse forming circuit (15) is inputted.
A gate circuit (17) is provided which performs a switching operation so as to pass the signal from the second pulse forming circuit (16) in the case of a continuous wave, and to pass the signal from the second pulse forming circuit (16) in the case of a continuous wave.
1. A continuous wave detection circuit characterized in that a switching circuit (18) is controlled by the output of ) to output a pulse signal. (2) A continuous wave detection system characterized in that the continuous wave detection circuit according to claim 1 is used in a receiving system of a monitoring radar or the like to enable signal processing and display of both pulse waves and continuous waves.