• 专利附录
  • 专利说明
  • 权利要求
  • 类似技术
  • 同族专利
  • 引用文献
  • 法律状态
  • 优先权
    • 专利摘要:

    公开号:NL8702132A
    申请号:NL8702132
    申请日:1987-09-08
    公开日:1998-02-02
    发明作者:
    申请人:Dassault Electronique；
    IPC主号:
    专利说明:

    Short designation: active electromagnetic radar disturbance device, and method for radar disturbance.
    The invention relates to electromagnetic radar disturbance, the object of which is to cause enticing and deception effects on systems of radar weapons with fire control of projectiles and cannons.
    In its siphon protection function, the purpose of electromagnetic radar disturbance is to generate target distortions against tracking radars or self-conductive radar radars (ground-to-air, air-to-air systems) in order to draw the gun or projectile fire at these false targets, referred to as the "lure or deception effect" is going to be.
    These false targets must be as credible from the viewpoint of the enemy radar system or projectile as the skin echo or drawing of the aircraft itself. Moreover, they must be more attractive than the aircraft so that the threat posed by this weapon system differs from the aircraft.
    The electromagnetic signals transmitted thereby are normally part of a radiation back onto the target. The radiated signals are increasingly processed coherently in the receivers to only recognize the position of the target relative to the weapon it is attacking, but also to derive the target's approach speed through Doppler processing .
    In fact, the Doppler processing allows for very good discrimination of moving targets from the ground disorder, further distinction between the different echoes delivered by different targets, and increased acuteness in tracking a target after initial recognition or " acquisition "thereof.
    The developed systems, called "Pulse-Doppler", are even capable of examining the correlation between the distance and velocity of the targets to remove all fictitious and unlikely echoes generated by elementary disturbance modes.
    Different flying aircraft can use a disturbance mode called "multi-carrier" which is particularly effective. Such a method is useless in the case of an isolated aircraft. In some cases, it must be content with basic perturbation modes, such as transmission through a continuous barrier noise jamming device. It is known to use counter-countermeasures in a self-conductor such as "target source of interference": the self-conductor is satisfied with the interference source being tracked by the aircraft no longer sweeping allowing it to unite with its target.
    It will therefore be understood that an isolated aircraft may be in a predicament.
    In addition, passive electromagnetic radar disrupters are known which use spangles, which are also referred to as "chaff" (anti-radar snow). These are convenient to use due to integrated radar jamming device lances with little weight gain. An aircraft can therefore occupy a very large number of spangles inexpensively and these can form an important equivalent radar surface provided the formation of the cloud they form after shedding is sensibly controlled. Combined with a noise disturbance, and possibly avoidance maneuvers ordered by the aircraft, these passive radar disturbances are effective, at least when the threat is equipped with a non-coherent radar.
    It is different in the opposite case, i.e. when the threatener uses a coherent radar. In fact, the distance-speed correlation then makes it possible to immediately recognize that it is a cloud of sequins and not an aircraft.
    In short, the sudden delay caused by the sequins after ejection creates easy speed discrimination on the part of enemy systems.
    The main object of the invention is to provide an active electromagnetic radar jamming device of high credibility, which is particularly effective with regard to enemies using a low level Doppler signal.
    Another object of the invention is to provide such a device that is inexpensive, small in size and lightweight, and also with a very simple electronic and mechanical structure.
    Another object of the invention is to provide such a radar disturbance device which is as little as possible subject to an initial speed jump upon its ejection from the aircraft.
    According to a general feature of the invention, the proposed active electromagnetic radar disturbing device, in combination: an antenna, a duplexer, which is connected to the antenna and has an output and an input, a fixed high-frequency amplification circuit which is connected between the output and the input of the duplexer and independent means for powering this amplification chain.
    According to another important feature of the invention, the gain circuit comprises at least one delay means and a fast switch modulator is arranged between the output and the input of the duplexer, in series with or in the gain chain. This provides a coherent responder with short-term broad band.
    The amplification circuit comprises at least two amplifiers, with a gain of at least 30 dB, with at least one delay line between them.
    In a special embodiment, the amplification chain is formed by two amplifiers, with a gain of 35 dB with a delay line of 10 nanoseconds between them and an attenuation of -5 dB. The modulator works with a rhythm corresponding to the length of the delay line and will therefore be at least several tens of Megahertz. For example, one will take 50 MHz.
    Preferably, the radar disturbing device additionally comprises a gain control device which is selective as a function of the frequency and which acts on the two amplifiers. This makes it possible in particular to compensate for the gain variations over the useful bandwidth in which the radar disturbing device can operate.
    In addition, the foods preferably comprise one or more lithium batteries or thermal batteries.
    It is advantageous if the duplexer is a circulator for limiting unwanted links between its input and output with respect to the gain circuit.
    In addition, the antenna is preferably a spiral antenna with a large angle opening.
    In a particular application, the radar disturbing device is mounted in a small-sized container or housing, such as a cartridge whose head dome contains the antenna and the rear portion of which contains the battery, as well as suitable aerodynamic members, such as fins, for minimizing the initial velocity of the cartridge at its launch.
    The cartridge may also contain a delayed acting self-destruct charge, energized at launch.
    In a special embodiment, the circulator and the switch modulator are arranged axially in the cartridge, surrounded by the amplifiers, which in turn are surrounded by a coaxial cable winding forming the delay line.
    The invention also provides a method of radar disturbance which consists in ejecting a radar disturbance device from an aircraft as explained above.
    It is very advantageous when this method involves energizing a noise member simultaneously with the ejection of the radar disturbing device, i.e. coincident with this ejection. The ejection of the radar disturbing device and / or the excitation of the noise element take place successively upon detection of a threat.
    The purpose of the murmur is to cover the drawing of the aircraft while the radar jamming device can generate a much more powerful signal that will progressively move away from the aircraft and thereby form a very credible fictional target for deflecting the threat.
    The invention will be elucidated with reference to the figures. In the figures shows:
    Figure 1 shows the electrical principle diagram of a radar disturbance device according to the invention; and
    Figure 2 shows an implantation example of this radar disturbance device in a cartridge.
    The figures, and in particular figure 2, comprise geometric elements. Therefore, they are included not only in the description for perfection thereof but also, if necessary, to contribute to the definition of the invention.
    In Figure 1, a wide-angle spiral antenna 1 is connected to a duplexer 2, which is a circulator here.
    The output of the circulator supplies a gain circuit 3 consisting of a first amplifier 31 with a gain of 35 dB, followed by a delay line 32, with a delay time of 10 nanoseconds and an attenuation of -5 dB.
    This delay line 32 is followed by a switch 35 associated with a 50 MHz controlled modulator 34. Finally, the switch 35 is followed by another amplifier 33, which is equal to the first, and which terminates the gain circuit 3 and therefore with the input of the circulator 2 is connected.
    The signals received by the spiral antenna 1 are therefore fed through the output of the circulator 2 to the amplification circuit 3 which returns the considerably amplified signals to the input of the circulator 2 for retransmission by the spiral antenna 1.
    Even when it is formed by a ferrite circulator, the multiplexer 2 does not guarantee perfect decoupling between its output and input. In fact, the loop gain formed by the gain circuit 3 is substantial and, moreover, the antenna itself provides only minor decoupling.
    The delay line 32 and the switch modulator 34 and 35 therefore intervene in combination.
    The delay line 32 accumulates receive signals during the time the switch 35 is open. When the delay line is filled, the switch 35 is closed, allowing retransmission of the stored signals up to the antenna 1. This can prevent the system from spontaneously oscillating on its own.
    The expert will understand that the interruption rhythm must first of all be fast enough not to be detected by the enemy radar. Moreover, it is desirable to limit the length of the delay line and thereby the losses generated by it to favor the amplification factor of the amplifiers as much as possible. The choice thereof, their number, their positions relative to the delay line and their respective amplification factors, should be considered as necessary to optimize the signal-to-noise ratio properties.
    As an alternative to the illustrated embodiment, three amplifiers can be used which are then separated by two delay lines. For its part, the modulator switch group can be arranged either in the amplification chain or outside it, provided it remains in the loop defined between the output and the input of the circulator 2.
    It is useful to provide a gain correction device 36 that acts on one of the amplifiers 31, 33 or better on both. The purpose of this correction device is to change the gain of the gain chain taking into account variations of the losses in the transmission line and the delay line, as a function of the frequency, and possibly with variations of the gain of the amplifiers as a function of the frequency.
    For example, amplifiers 31 and 33 may be monolithic amplifiers having gallium arsenide as the semiconductor and whose output power is up to 500 mW or 1 W. Their electrical supply can be provided by a lithium battery. They can cover a frequency band of 7 to 16.5 GHz corresponding to the aforementioned threats with a low Doppler level.
    The system thus obtained reacts directly in every high-frequency band of the amplifiers. It can have a total gain of 62 dB. Taking into account the loss due to the rapid interruption, this gives an equivalent 2 radar area of about 15 m, as a linear function, i.e.
    prior to saturation of the amps. The equivalent 2 radar image of a military aircraft can be up to 5 m, from which it follows that the radar disturbing device according to the invention is at least three times more powerful than the radar drawing of the aircraft which is masked by the aforementioned crossover.
    In a particular application, the radar disturbing device as shown in Figure 2 is patterned.
    The antenna 1 is arranged behind a dome 51 forming the head of the cartridge 5. The rear portion 52 thereof, which is provided with fins 58, which on the one hand permits ejection of the cartridge at a low speed relative to the aircraft and on the other hand permits stabilization of the cartridge in the air jets so that it does not decelerate too quickly , preferably contains a destruction charge 56. The lithium battery 4 is arranged on its side.
    The circulator 2 and the modulator / switch group 34, 45 are arranged on the shaft between this battery and the antenna. The two amplifiers 31, 33 (or possibly more) can be arranged on either side. Finally, a coaxial cable 32 defining the delay line (possibly delay lines) is wound around the group. The connections between the various elements are realized in a manner known to those skilled in the art by means of decoupling with waveguides and the waveguide / coax transitions.
    The radar jamming device is used as follows: ejection from the aircraft, simultaneously energizing the destruction charge 56, which will destroy the radar jamming device after a selected time, - low relative speed of the radar jamming device to the aircraft, and stabilizing the radar jamming device in the direction of the air flows using the fins 58 so that the device maintains a regular and continuous delay relative to the aircraft, application of noise generation which is also automatically started by the ejection.
    Simultaneously or quasi-simultaneously, the threat detection means will have started the aircraft noise element which then masks the radar drawing thereof, which can also take place during avoidance maneuvers.
    On the noise side, a target will be visible whose radar drawing dominates that of the aircraft without being more powerful than this, with the threatener likely to be misled by this radar disruption device.
    It will be apparent to those skilled in the art that the invention, with great efficiency and great cost control of resources, provides a significant improvement in material self-protection and in aircraft, especially when isolated.
    权利要求:
    Claims (14)
    [1]
    An electromagnetic radar disturbing device characterized by: an antenna (1), a duplexer (2), which is connected to the antenna and has an output and an input, a fixed high-frequency amplification circuit (3) which is between the output and the input of the duplexer connected and independent resources (4) to feed this reinforcement chain.
    [2]
    Radar jamming device according to claim 1, characterized in that the amplification circuit (3), at high amplification, comprises at least one delay means (32) and that a fast switch is connected between the output and the input of the duplexer in series or in the amplification chain. modulator (34, 35) is provided, providing a coherent responder with transient broad band.
    [3]
    Radar interference device according to claim 2, characterized in that the amplification chain comprises at least two amplifiers (31, 33) with at least a gain of 30 dB with a delay line (32) in between.
    [4]
    Radar interference device according to claim 3, characterized in that the amplification circuit comprises two amplifiers (31, 33) with gain 35 dB with a delay line of 10 nanoseconds and an attenuation of -5 dB between them.
    [5]
    Radar interference device according to claim 4, characterized by a gain control device (36) which is selective as a function of the frequency and acts on the two amplifiers.
    [6]
    Radar interference device according to claim 4 or 5, characterized in that the modulator (34) operates on at least a few tens of Megahertz.
    [7]
    Radar interference device according to one of the preceding claims, characterized in that the power supply means (4) comprise a lithium battery.
    [8]
    Radar disturbance device according to one of the preceding claims, characterized in that the duplexer (2) is a circulator.
    [9]
    Radar disturbing device according to one of the preceding claims, characterized in that the antenna (1) is a spiral antenna.
    [10]
    Radar interference device according to any one of the preceding claims, characterized in that the device is arranged in a container of limited dimensions such as a cartridge whose dome of the head contains the antenna and the rear part of which (52) contains the battery and also suitable aerodynamic means (58) for minimizing the initial velocity of the cartridge at its launch.
    [11]
    Radar interference device according to claim 10, characterized in that the cartridge also contains a delayed self-destruct charge (56) energized at launch.
    [12]
    Radar interference device according to claim 10 or 11, in combination with any one of claims 2 to 6, characterized in that the circulator (2) and the switch / modulator (34, 35) are arranged axially in the cartridge by the amplifiers (31, 33), which in turn are surrounded by a coil (32) of a coaxial cable forming the delay line.
    [13]
    A method of electromagnetic radar disturbance characterized by ejecting a radar disturbing device according to any one of the preceding claims from an aircraft.
    [14]
    A method according to claim 13, characterized by energizing a jamming means upon shedding the radar jamming device following detection of a threat to cover the aircraft's drawing.
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    同族专利:
    公开号 | 公开日
    NL194250C|2001-10-02|
    DE3732032C1|1997-05-22|
    FR2739193B1|1998-04-03|
    NL194250B|2001-06-01|
    FR2739193A1|1997-03-28|
    BE1012189A4|2000-07-04|
    引用文献:
    公开号 | 申请日 | 公开日 | 申请人 | 专利标题
    US3187258A|1962-11-27|1965-06-01|Sperry Rand Corp|Saturable multi-mode responder|
    US3720952A|1964-12-29|1973-03-13|L Lawsine|Signal processing apparatus|
    US3909828A|1965-11-23|1975-09-30|Us Navy|Airborne repeater decoy|
    DE3346155A1|1983-12-21|1985-07-04|Licentia Patent-Verwaltungs-Gmbh, 6000 Frankfurt|FLIGHT BODY FOR INTERFERENCE WITH GROUND-BASED TRANSMITTER RECEIVING DEVICES|
    法律状态:
    1998-02-02| A1A| A request for search or an international-type search has been filed|
    1998-04-01| BB| A search report has been drawn up|
    1998-09-01| BC| A request for examination has been filed|
    2004-06-01| V1| Lapsed because of non-payment of the annual fee|Effective date: 20040401 |
    优先权:
    申请号 | 申请日 | 专利标题
    FR8613283A|FR2739193B1|1986-09-23|1986-09-23|ACTIVE ELECTROMAGNETIC LURE, AND LURE METHOD|
    FR8613283|1986-09-23|
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