JP2020003389A - Reflection controller and detection obstructing device - Google Patents

Abstract

To provide a reflection controller which can make it difficult to be detected by a rader device on the other side.SOLUTION: A reflection control unit 10A as a reflection controller includes: a mixer 22 for generating a modulation wave formed by mixing an RF signal received as an electric wave and a noise signal 51 generated separately from the RF signal; and an amplifier 23 for amplifying and outputting the modulated wave generated by the mixer 22.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a reflection control device and a detection / jamming device that generate a signal to be transmitted to a counterpart radar device.

  The radar device emits a radar wave toward a target, receives a reflected wave of the radar wave reflected by the target, and detects a distance to the target and the like based on the received reflected wave.

  A technique for hindering detection by the other party's radar device is described in, for example, Patent Document 1. The jamming device described in Patent Document 1 has a function of receiving a radar signal transmitted from a counterpart radar device and generating the same signal as the received radar signal in order to prevent detection by the counterpart radar device and its function. It has the function of adding a time delay to radar signals and transmitting them.

JP-A-5-87907

  However, in Patent Document 1 as the conventional technique, it is necessary to provide a signal generator for generating the same signal as the radar signal received from the other party, or to store the received radar signal in a memory, There is a problem that the device becomes larger. In addition, although a time delay is performed as a disturbing means, there is a problem that if the delay time becomes apparent, the effect of the disturbing is lost.

  The present invention has been made in view of the above, and an object of the present invention is to provide a reflection control device and a detection obstruction device that can be hardly detected by a counterpart radar device.

  In order to solve the above-described problems and achieve the object, the reflection control device and the detection and jamming device of the present invention are generated as a first signal received as a radio wave and a signal different from the first signal. A mixing unit that generates a modulated wave by mixing the second signal, which is a signal, and a level adjustment unit that adjusts and outputs the signal level of the modulated wave or the first signal.

  ADVANTAGE OF THE INVENTION According to this invention, it is effective in being hard to be detected by the radar apparatus of the other party.

The figure which shows the structure of the detection obstruction apparatus concerning embodiment. FIG. 2 is a diagram illustrating a first configuration example of a reflection control unit according to the embodiment; FIG. 3 is a diagram illustrating a second configuration example of the reflection control unit according to the embodiment; FIG. 4 is a diagram for explaining a signal transmitted by the detection and jamming device according to the embodiment;

  Hereinafter, embodiments of a reflection control device and a detection / obstruction device according to the present invention will be described in detail with reference to the drawings. It should be noted that the present invention is not limited by the embodiment.

Embodiment.
FIG. 1 is a diagram illustrating a configuration of a detection and jamming device according to an embodiment. The detection and obstruction device 100 includes a reception antenna 21, a reflection control unit 10X that is a reflection control device, and a transmission antenna 25. The detection and disturbance device 100 is arranged in a radar device or the like.

  The receiving antenna 21 receives an RF (Radio Frequency) signal radiated by the other radar device, and inputs the received RF signal to the reflection control unit 10X. The reflection control unit 10X mixes the received RF signal with a noise signal to generate a modulated wave, adjusts the signal level of the modulated wave, and inputs the modulated wave to the transmission antenna 25. The transmission antenna 25 radiates the modulated wave generated by the reflection control unit 10X. The modulated wave radiated by the transmitting antenna 25 has a large amount of noise included in the RF signal so that only the reflected wave of the RF signal is not directly received by the other radar device. Therefore, the signal that the reflection control unit 10X mixes with the received RF signal may be other than noise, but a signal that makes it difficult for the other radar device to detect the reflected wave of the RF signal is desirable.

  In the detection and jamming device 100, for example, the receiving antenna 21 and the transmitting antenna 25 are arranged on the side surface of the cylindrical member, and the reflection control unit 10X is arranged inside the cylindrical member.

  FIG. 2 is a diagram illustrating a first configuration example of the reflection control unit according to the embodiment. Here, a configuration of a reflection control unit 10A which is a first example of the reflection control unit 10X will be described.

  The reflection control unit 10A includes a mixer 22, an amplifier 23, and an attenuator 24. The mixer 22 is a circuit for mixing signals, the amplifier 23 is a circuit for amplifying the signal level, and the attenuator 24 is a circuit for attenuating the signal level. The mixer 22 here is a mixing unit, and the amplifier 23 and the attenuator 24 are a level adjustment unit. Note that the reflection control unit 10A may not include the attenuator 24.

  The receiving antenna 21 is connected to a mixer 22, and the mixer 22 is connected to an amplifier 23. The amplifier 23 is connected to an attenuator 24, and the attenuator 24 is connected to a transmission antenna 25.

  Receiving antenna 21 receives the RF signal radio wave radiated from the radar apparatus of the other party, and inputs this RF signal to mixer 22. The mixer 22 mixes a modulated signal, which is a mixed signal, by mixing an RF signal as a first signal and a second signal generated by the reflection control unit 10A that is different from the RF signal. Input to the amplifier 23. An example of the second signal is a noise signal 51. That is, the mixer 22 superimposes the noise signal 51 near the frequency of the RF signal and inputs the signal to the amplifier 23. Thus, the modulated wave input to the amplifier 23 by the mixer 22 becomes a noise wave close to the frequency of the radio wave radiated from the other radar device. The noise signal 51 is a low frequency signal including a direct current (DC) signal. Here, the DC signal includes frequencies in a range that can be regarded as the frequency of the DC signal. Since the DC signal also includes a noise component, the mixer 22 mixes the noise component signal with the RF signal. The noise signal 51 may have any frequency as long as it has a small frequency. Further, the noise signal 51 may include a plurality of signals having different frequencies, such as 1 Hz and 1.1 Hz. Further, the noise signal 51 may be generated by a noise generator that randomly generates a noise signal. That is, the noise signal 51 may include a plurality of signals having random frequencies.

  The amplifier 23 amplifies the signal level of the modulated wave so that the signal level of the modulated wave approaches the signal level of the RF signal reflected by the body of a platform such as an airplane equipped with the detection and jamming device 100. There is a proportional relationship between the signal level of the RF signal reflected by the body of the platform on which the detection and jamming device 100 is mounted and the signal level of the RF signal received by the receiving antenna 21. Therefore, the amplifier 23 performs amplification corresponding to the proportional relationship determined in advance. That is, the amplifier 23 adjusts the signal level of the RF signal to a magnitude corresponding to the signal level when the RF signal is received. In the following description, the signal level of the RF signal reflected by the body of the platform on which the detection and jamming device 100 is mounted may be referred to as a target signal level. The amplifier 23 inputs the modulated wave to the attenuator 24.

  When the signal level of the modulation wave is higher than the target signal level, the attenuator 24 attenuates the modulation wave so as to approach the target signal level. The attenuator 24 inputs the modulated wave to the transmission antenna 25. The transmission antenna 25 transmits the modulated wave from the attenuator 24.

  When the reflection control unit 10A is applied to the detection and jamming device 100, the other radar device converts the RF signal reflected by the body of the platform on which the detection and jamming device 100 is mounted and the modulated wave from the detection and jamming device 100. Receive. In other words, the other radar device receives the RF signal reflected from the body of the platform and the modulated wave incident on the receiving antenna 21 and modulated by the reflection control unit 10A among the radiated RF signals. As a result, in the other radar device, the noise level of the received signal increases, and the signal-to-noise (S / N) ratio, which is the signal-to-noise ratio, deteriorates. As a result, in the other radar device, the target detection capability is reduced.

  Note that, in the reflection control unit 10A, an RF signal may be slightly output from the mixer 22 to the amplifier 23. When this RF signal is transmitted from the transmitting antenna 25 via the amplifier 23 and the attenuator 24, the RF signal which is a carrier wave from the other radar device leaks. That is, the detection and jammer 100 may transmit the received RF signal together with the modulated wave. Here, a configuration of the reflection control unit 10X that can prevent the transmission of the RF signal received from the other party's radar device will be described.

  FIG. 3 is a diagram illustrating a second configuration example of the reflection control unit according to the embodiment. Here, the configuration of a reflection control unit 10B that is a second example of the reflection control unit 10X will be described. Components that achieve the same functions as those of the reflection control unit 10A shown in FIG. 2 among the components in FIG. 3 are denoted by the same reference numerals, and redundant description will be omitted.

  The reflection control unit 10B includes a frequency divider 31, an amplifier 32, a harmonic mixer 33 as a mixing unit, and an attenuator 24. The frequency divider 31 is a circuit that converts the frequency of the input RF signal to a half frequency, and the amplifier 32 is a circuit that amplifies the signal level, like the amplifier 23. The harmonic mixer 33 is a circuit that mixes a signal having a frequency twice as high as that of the input signal and the noise signal 51. Here, the harmonic mixer 33 is a mixing unit, and the amplifier 32 and the attenuator 24 are a level adjustment unit.

  The receiving antenna 21 is connected to a frequency divider 31, and the frequency divider 31 is connected to an amplifier 32. The amplifier 32 is connected to a harmonic mixer 33, and the harmonic mixer 33 is connected to an attenuator 24, and the attenuator 24 is connected to a transmission antenna 25. The reflection control unit 10B does not need to include the attenuator 24.

  When receiving the radio wave of the RF signal radiated from the other radar device, the receiving antenna 21 inputs the RF signal to the frequency divider 31. The frequency divider 31 converts the frequency of the input RF signal into a half frequency and inputs the frequency to the amplifier 32. The amplifier 32 amplifies the signal level of the RF signal from the frequency divider 31 so that the signal level of the RF signal from the frequency divider 31 approaches the target signal level. The amplifier 32 inputs the RF signal to the harmonic mixer 33.

  The harmonic mixer 33 mixes the RF signal whose frequency has been converted and the noise signal 51 whose frequency is low, and inputs a modulated wave that is a mixed signal to the attenuator 24. Specifically, the harmonic mixer 33 mixes the noise signal 51 with a signal having a frequency twice as high as the RF signal input from the amplifier 32. The harmonic mixer 33 inputs the modulated wave obtained by the mixing to the attenuator 24. Thus, the modulated wave input to the attenuator 24 by the harmonic mixer 33 becomes a noise wave close to the frequency of the radio wave radiated from the other radar device.

  When the signal level of the modulation wave is higher than the target signal level, the attenuator 24 attenuates the modulation wave so as to approach the target signal level and inputs the attenuation to the transmission antenna 25. The transmission antenna 25 transmits the modulated wave from the attenuator 24.

  As described above, in the case where the reflection control unit 10B is applied to the detection / jamming device 100, similarly to the case where the reflection control unit 10A is applied, the noise level of the signal to be received becomes high in the other radar device, and the signal pair The S / N ratio, which is the noise ratio, deteriorates.

  Further, when the reflection control unit 10B is applied to the detection and jamming device 100, even if a small RF signal is output from the harmonic mixer 33, the frequency of the RF signal output from the harmonic mixer 33 is One half of the frequency of the RF signal. That is, even when the RF signal is transmitted from the transmission antenna 25, a signal having a frequency half that of the RF signal that is a carrier wave leaks. The other radar device detects a target position or the like by receiving a reflected wave of the emitted RF signal. For this reason, it is difficult for the partner radar device to detect the position of the target or the like even if it receives a signal having a frequency different from the reflected wave of the emitted RF signal. Therefore, even when the other party's radar device receives an RF signal having half the frequency of the RF signal, the other party's radar device detects a platform such as an airplane equipped with the detection and interference device 100. Is less likely to be done. The platform on which the detection and obstruction device 100 is mounted is not limited to an airplane, and may be a satellite, a ship, a vehicle, a flying object other than an airplane, or the like.

  FIG. 4 is a diagram for explaining a signal transmitted by the detection and jamming device according to the embodiment. The horizontal axis of the graph shown in FIG. 4 is frequency, and the vertical axis is signal level. The waveform shown in FIG. 4 is a signal waveform at a certain timing.

  The signal level L3 is the level of the signal 43 reflected by the body of the platform on which the detection and jamming device 100 is mounted. The signal 43 is a reflected signal corresponding to the RF signal radiated from the other radar device. The signal level L1 is the level of the noise signal 41 received by the other radar device when the platform is not equipped with the detection and jamming device 100, and the signal level L2 is the level of the noise detection and jamming device 100 mounted on the platform. , The level of the noise signal 42 received by the other party's radar device. Here, the signal level L3 is higher than the signal levels L1 and L2, and the signal level L2 is higher than the signal level L1.

  When a radio wave of an RF signal having a specific frequency band is radiated from the radar apparatus of the other party, the signal 43 of the signal level L3 is reflected on the body of the platform on which the detection and jamming apparatus 100 is mounted.

  When the detection and jamming device 100 is not mounted on the platform, the other radar device receives the signal 43 of the signal level L3 and the noise signal 41 of the signal level L1. On the other hand, when the detection and jamming device 100 is mounted on the platform, the detection and jamming device 100 mixes the RF signal and the noise signal 51 received from the other party's radar device, and then transmits a modulated wave to the other party's radar device. . This corresponds to the detection / jamming device 100 generating and transmitting the noise signal 42 having the signal level L2 larger by ΔL than the signal level L1. That is, the detection jammer 100 reflects the signal 43 of the signal level L3 and transmits the noise signal 42 of the signal level L2 close to the signal level L3. Thus, the other radar device receives the signal 43 of the signal level L3 and the noise signal 42 of the signal level L2 close to the signal level L3. Since the frequency and signal level of the signal 43 and the noise signal 42 are close to each other, it is difficult for the other radar device to separate the signal 43 and the noise signal 42, and it is difficult to detect the signal 43.

  As described above, the detection and jammer 100 transmits the noise signal 42 having the signal level L2 close to the signal level L3, so that the S / N ratio of the other radar device can be deteriorated.

  As a method of realizing detection interference with the other party's radar device, there are a method of reducing a signal received by the other party and a method of increasing a noise signal received by the other party in order to deteriorate the SN ratio.

  First, a method for reducing the signal received by the other party will be described. The method of reducing the signal received by the other party is a method of lowering the signal level L3 of the signal 43 while keeping the signal level L1 of the noise signal 41 shown in FIG.

  This method includes a method of reducing reflected waves by absorbing radio waves radiated from the other party's radar device with an absorber, and a method of scattering radio waves from the other party's radar device in directions other than the direction of arrival. There is a method of reducing the reflected wave received by the other party by applying to a platform.

  In the method using the absorber, the level of the RCS depends on the material properties of the absorber, so that maintenance of the absorber is required to maintain the material properties, resulting in a problem that the cost is increased. Further, in the method of applying a shape that scatters reflected waves to a platform, the platform must have a special shape, which imposes restrictions on the shape and dimensions of equipment mounted inside the platform.

  Further, as a method of increasing the noise signal received by the other party, there is a method of transmitting an interference wave from the own apparatus and increasing the noise signal received by the radar apparatus of the other party. However, in this method, the frequency of the interference wave must match the frequency of the radio wave from the other party. Further, since the interfering wave must be continuously transmitted, the own aircraft cannot perform the radar detection operation while transmitting the interfering wave. In addition, since the interfering wave is transmitted, the other party can easily detect the interfering wave.

  In order to make it difficult for the other radar device to detect the noise signal, the noise signal to be received by the other radar device must be close to the frequency of the RF signal radiated from the other radar device. In the detection / jamming device 100, since the modulation is executed by superimposing a low-frequency noise signal on the RF signal radiated from the other party, the frequency of the modulated wave matches the frequency of the received RF signal. For this reason, the detection and jammer 100 does not need any special processing for matching the frequency of the jammed wave that is a modulated wave with the frequency of the radio wave from the other party. Further, since the detection / jamming device 100 generates the modulated wave using the received RF signal, the modulated wave can be transmitted with a reduced delay.

  Also, the detection / jamming device 100 can superimpose and transmit the noise signal 51 only when receiving the radio wave emission from the other party, and can emit the radio wave from the radar device regardless of the operation of the detection / jamming device 100. .

  Further, since the detection / jamming device 100 transmits the modulated wave at the same timing as the echo of the radio wave emitted by the other party's radar device, it is difficult for the other device's radar device to detect. The echo received by the other party's radar device is obtained by reflecting the radio wave emitted by the other party's radar device on the platform on which the detection and interference device 100 is mounted.

  As described above, in the detection and jamming device 100, the signal level of the noise signal received by the other radar device is increased, so that the RF signal reflected by the platform on which the detection and jamming device 100 is mounted and the noise signal 41 are combined. The difference in signal level can be reduced. Thereby, similarly to the case where the signal level of the RF signal reflected by the platform on which the detection and jamming device 100 is mounted is reduced, the detection and jamming for the other radar device can be realized. Further, the detection and jamming device 100 does not require an absorber for the RF signal, and does not need a shape for scattering the reflected wave with respect to the RF signal.

  By providing the transmission antenna 25 with directivity, a modulated wave to which the noise signal 51 is added may be transmitted only in the direction of arrival of the RF signal received from the other party. As a result, unnecessary emission of radio waves can be prevented. The detection and interference device 100 may detect the direction of arrival of the RF signal by a sensor, or may calculate the direction of arrival based on the RF signal received by the receiving antenna 21.

  As described above, the detection and jamming apparatus 100 according to the embodiment generates and transmits a modulated wave obtained by mixing the RF signal received from the other radar apparatus and the noise signal 51 having a frequency lower than the specific frequency. . This makes it difficult for the other radar device to detect the RF signal reflected by the platform on which the detection and jamming device 100 is mounted. Therefore, the detection and obstruction device 100 can be hardly detected by the other party's radar device.

  In addition, when the noise signal 51 includes a plurality of signals having different frequencies, the detection and disturbance device 100 can generate a modulated wave including many frequencies. Is less likely to be detected by the other party's radar device than when the frequency is one frequency.

  Further, when the noise signal 51 includes a plurality of signals having random frequencies, a modulated wave including a random frequency can be generated. Therefore, the frequency of the noise signal 51 is fixed. This makes it more difficult for the other party's radar device to detect the situation as compared with the case in which it is performed.

  The configurations described in the above embodiments are merely examples of the contents of the present invention, and can be combined with other known technologies, and can be combined with other known technologies without departing from the gist of the present invention. Parts can be omitted or changed.

  10A, 10B, 10X reflection control unit, 21 receiving antenna, 22 mixer, 23, 32 amplifier, 24 attenuator, 25 transmitting antenna, 31 divider, 33 harmonic mixer, 41, 42, 51 noise signal, 43 signal, 100 detection Jamming device.

Claims (9)

A mixing unit that generates a modulated wave by mixing a first signal received as a radio wave and a second signal that is a signal different from the first signal and that is generated;
A level adjusting unit that adjusts and outputs a signal level of the modulated wave or the first signal;
A reflection control device comprising: The second signal includes a plurality of signals having different frequencies.
The reflection control device according to claim 1, wherein: The second signal includes a plurality of signals having random frequencies,
The reflection control device according to claim 1, wherein: The second signal is a signal of a noise component included in the DC signal,
The reflection control device according to claim 1, wherein: The level adjustment unit includes an amplifier that amplifies the signal level of the modulated wave,
The reflection control device according to any one of claims 1 to 4, wherein: A frequency divider for converting a frequency of the radio wave signal to a half frequency;
The mixing unit is a harmonic mixer that mixes a signal having a frequency twice as high as the signal converted to the half frequency and the second signal.
The reflection control device according to any one of claims 1 to 5, wherein: The level adjustment unit adjusts the first signal to a magnitude corresponding to a signal level when the first signal is received, and outputs the adjusted first signal.
The reflection control device according to any one of claims 1 to 6, wherein: A receiving antenna for receiving radio waves,
A reflection control device that generates a modulated wave using the received radio waves,
A transmitting antenna for transmitting the modulated wave,
Has,
The reflection control device,
A mixing unit that generates a modulated wave by mixing a first signal received as a radio wave and a second signal that is a signal different from the first signal and that is generated;
A level adjusting unit that adjusts and outputs a signal level of the modulated wave or the first signal;
A detection and jamming device comprising: The transmission antenna has directivity, and transmits the modulated wave in the direction of arrival of the radio wave,
The detection and jamming device according to claim 8, wherein:

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