JPH0525380U - Tracking receiver - Google Patents

Abstract

(57) [Abstract] [Purpose] To obtain a device in which the power spectrum of a pulse of a range gate becomes an unnecessary signal and does not cause a problem that the signal-to-noise ratio of a tracking receiver is deteriorated. [Configuration] A pulse having a phase opposite to that of the range gate pulse is generated and added to the range gate pulse leaked into the IF system of the receiver.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a tracking receiver used for a pulse radar.

[0002]

[Prior Art]

 FIG. 3 is a block diagram showing a part of the configuration of a conventional tracking receiver for pulse radar of this type. In the figure, 1 is a low noise amplifier, 2 is a mixer, 3 is an IF amplifier, 4 is an IF gate circuit, 5 is a detector, and 6 is a video amplifier.

In the configuration of FIG. 3, the received signal from the target is input to the low noise amplifier 1 and converted into an IF signal by the mixer. This IF signal is input to the IF gate circuit 4 after being amplified by the IF amplifier 3 to an appropriate level.

In the IF gate circuit 4, the signal is passed only during the time when there is a received signal from the target, and the gate is cut off during the other time. This control is performed by the range gate pulse VR, and FIG. 4 shows the state of these timings. That is, the IF gate circuit 4 plays a role of removing unnecessary signals and noise and improving the signal-to-noise ratio.

The received signal from the target that has passed through the IF gate circuit 4 is converted into a video frequency by the detector 5, amplified by the video amplifier 6, and then sent to the signal processing unit.

[0006]

[Problems to be solved by the device]

 However, this type of conventional tracking receiver has a problem. When the frequency is plotted on the horizontal axis of the range gate pulse VR, its power spectrum is as shown in FIG. 5, and its components spread to the IF frequency band. Therefore, this power spectrum leaks from the IF gate circuit 4 of FIG. 3 into the receiving system, and is converted into a video frequency by the detector 5. The leakage of the range gate pulse VR converted to the video frequency is amplified by the video amplifier 6 and is output to the signal processing unit as an unnecessary video signal. This unnecessary video signal is as shown in FIG. 6, which is a serious problem for the tracking radar receiver.

[0007]

[Means for Solving the Problems]

 The present invention has been made to solve the above problems, and one of them is to add a pulse having a phase opposite to that of the range gate pulse VR to the range gate pulse leaked into the IF system of the generation receiver. Is.

The other is to install a circuit having a range gate function at the rearmost position of the receiver, that is, at the subsequent stage of the video amplifier.

[0009]

[Action]

 In other words, if the range gate pulse that leaks into the receiving system is added with a pulse in the opposite phase to the range gate pulse, the size of the range gate pulse that leaks into the receiving system becomes extremely small, and it is hardly output to the video output. Therefore, it is convenient for the tracking receiver.

If a circuit having a range gate function is installed at the rearmost position of the receiver, the range gate pulse leaked into the receiving system will not be further amplified, so that the range output to the video output will be Gate leakage is significantly smaller than conventional devices of this type.

[0011]

【Example】

 Example 1. FIG. 1 is a block diagram showing an embodiment of the present invention and shows a part of the configuration of a tracking receiver. In the figure, 1 to 6 are the same as those of the conventional device, 7 is an adder, and 8 is a gate pulse inverting circuit.

Next, the operation will be described. In FIG. 1, the operation until the reflected signal from the target is output from the IF gate circuit 4 is the same as that of the conventional device, and therefore the description thereof is omitted.

In FIG. 1, the output signal of the IF gate circuit 4 is input to the adder 7. At this time, the received signal from the target and the range gate pulse leak are mixed. On the other hand, a gate pulse inverting circuit 8 inputs a pulse obtained by inverting the polarity of the range gate pulse VR as shown in FIG. 7 to the adder 7. If the amplitude of the output pulse of the gate pulse inversion circuit 8 is set to be the same as the range gate pulse leakage, and the time relationship is also set to be the same, the output of the adder 7 Only the received signal from the target is present, and the range gate pulse leakage is eliminated.

Next, the output signal of the adder 7, that is, the received signal from the target is converted into a video frequency by the detector 5, amplified by the video amplifier 6, and then sent to the signal processing unit.

Example 2. FIG. 2 is a block diagram showing another embodiment of the present invention and shows a part of the configuration of the tracking receiver. In the figure, 1 to 3 and 5, 6 are the same as the conventional device, 9 is a video gate circuit (1), and 10 is a video gate circuit (2).

Next, the operation will be described. In the configuration of FIG. 2, the received signal from the target is input to the low noise amplifier 1 and converted into an IF signal by the mixer 2. The IF signal is amplified by the IF amplifier 3 to an appropriate size and then input to the detector 5 to be converted into a video frequency. This video signal is amplified by the video amplifier 6 and input to the video gate circuit (1) 9.

In the video gate circuit (1) 9, the signal is passed only during the time when the received signal from the target is present, and the gate is cut off during the other time. This control is performed by the range gate pulse VR, and the timing relationship between the received signal from the target and the range gate pulse VR is the same as that described in the description of the conventional device.

Next, the output signal of the video gate circuit (1) 9 is input to the video gate circuit (2) 10. The video gate circuit (2) 10 has exactly the same function as the video gate circuit (1) 9, and here again, the signal is passed only during the time when the reception signal from the target is present, and the output signal is sent to the signal processing unit. To do.

The double provision of the video gate circuit is to compensate for the drawback that the ON / OFF isolation of the gate is smaller than that of the IF gate circuit.

With such a configuration, unlike the configuration by the conventional device, the range gate pulse leakage is not amplified, so that the unnecessary video signal sent to the signal processing unit has a very small level. Can be suppressed.

[0021]

[Effect of the device]

 As described in detail above, by using the present invention, the amount of leakage of the range gate pulse can be made extremely small, so that a great effect that the signal-to-noise ratio of the radar device can be greatly improved can be obtained.

[Brief description of drawings]

FIG. 1 is a block diagram showing a part of a configuration of a tracking receiver according to a first embodiment of the present invention.

FIG. 2 is a block diagram showing a part of a configuration of a tracking receiver according to a second embodiment of the present invention.

FIG. 3 is a block diagram showing a part of a configuration of a conventional tracking receiver.

FIG. 4 is a waveform diagram illustrating the operation of the present invention.

FIG. 5 is a waveform diagram for explaining the operation of the present invention.

FIG. 6 is a waveform diagram for explaining the operation of the present invention.

FIG. 7 is a timing diagram illustrating the operation of the present invention.

[Explanation of symbols]

 1 Low Noise Amplifier 2 Mixer 3 IF Amplifier 4 IF Gate Circuit 5 Detector 6 Video Amplifier 7 Adder 8 Gate Pulse Inversion Circuit 9 Video Gate Circuit (1) 10 Video Gate Circuit (2)

Claims (2)

[Scope of utility model registration request] 1. A low noise amplifier for amplifying a received signal from a target, a mixer for converting an output signal of the low noise amplifier into an IF signal, an IF amplifier for amplifying an output signal of the mixer, and an IF amplifier for the IF amplifier. An IF gate circuit that has the function of passing only the output signal, that is, the received signal from the target and attenuating other unnecessary signals, and the above-mentioned range gate pulse is input, and the range gate pulse is input. A gate pulse inverting circuit that outputs a phase inverting pulse, an adder that adds the gate pulse inverting circuit output pulse and the IF gate circuit output signal, and a detector that converts the output signal of the adder into a video signal, A tracking receiver comprising a video amplifier that amplifies the output signal of this detector and sends it to the signal processing unit. . 2. A low noise amplifier for amplifying a received signal from a target, a mixer for converting an output signal of the low noise amplifier into an IF signal, an IF amplifier for amplifying an output signal of the mixer, and an IF amplifier for the IF amplifier. A detector that converts the output signal to a video signal, a video amplifier that amplifies the output signal of this detector, and a function that passes only the output signal of this video amplifier, that is, the received signal from the target, and attenuates other unnecessary signals And a tracking receiver comprising a two-stage video gate circuit controlled by a range gate pulse.