RU-1841396-C - Device for creating a speed-deflecting interference

Abstract

FIELD: aircraft protection against guided missile. SUBSTANCE: invention relates to the field of aircraft protection against guided missile guidance systems, in particular, to devices for creating a speed-diverting jamming signal. The claimed device consists of two phase shifters connected in series, with a modulating oscillation generator connected to one of them and a noise generator connected to the other through a noise amplitude control circuit. A control voltage generator is connected to the input of the modulating oscillation generator, and its second output is connected to the noise amplitude control circuit. EFFECT: technical result is to provide an effect on systems that have a speed channel protection against jamming, while maintaining a minimum energy potential for the jamming station. 1 cl, 2 dwg

Inventors

• BELYAEV YURIJ NIKOLAEVICH
• GUSEV YURIJ STEPANOVICH
• MATVEEV VYACHESLAV ALEKSANDROVICH
• Meleshenkov Yurij Timofeevich
• Ogievskij Vsevolod Vasilevich

Assignees

• Акционерное общество "Центральный научно-исследовательский радиотехнический институт имени академика А.И. Берга"

Dates

Publication Date

20260506

Application Date

19710611

Claims (1)

1. A device for creating a speed-deflecting interference consisting of two series-connected phase shifters, to one of which a modulating oscillation generator is connected, and to the other, through a noise amplitude control circuit, a noise generator, characterized in that, for the purpose of influencing systems that have protection of the speed channel from interference with the minimum energy potential of the interference station, a control voltage generator is connected to the input of the modulating oscillation generator, the second output of which is connected to the noise amplitude control circuit.

Description

Modern jamming stations designed to individually protect aircraft from missile guidance systems contain a range of devices that generate various types of interference. A mandatory component of this system is a velocity-deflecting jammer. This is due to the widespread use of missile guidance systems operating in continuous and quasi-continuous modes (such as the Hawk, Super Hawk, Sparrow, Bloodhound-2, and others) and the role of the velocity-deflecting jammer. While this type of jamming is effective against systems with a limited search range, it is used in combination with angle-measuring jammers to reduce the jamming station's power requirements. It is also an integral part of such promising aircraft defense methods as missile retargeting to chaff clouds, the underlying surface, and decoys. In known jamming stations, the velocity-distorting interference is typically created by phase-modulating the TWT with a sawtooth voltage, the frequency of which smoothly varies from 50-100 Hz to a certain desired value. As a result, the repeater-type jammer retransmits the radar's probing signal, the Doppler frequency of which gradually shifts in one direction or another (depending on the phase of the modulating sawtooth oscillations) from the Doppler frequency of the signal reflected from the protected aircraft, dragging along the radar's speed-tracking strobe (homing head) due to the interference's superior energy over the target signal. However, modern and future missile guidance systems employ special measures to protect against speed-distorting jamming [1, 2], which significantly reduce their effectiveness. These protection circuits operate by diverging the Doppler frequencies of the jamming and signal by an amount greater than the so-called deadband (2-4 times the speed tracking strobe width). These signals are compared based on certain parameters, and the one with the highest probability of matching the signal reflected from the aircraft is selected for further tracking. Consequently, to disrupt the normal operation of the protection circuits, it is necessary to eliminate the possibility of comparing the jamming and signal. This idea is realized using the proposed speed-distorting jamming device. The radar's probing signal enters the receiving antenna (1) of the jamming station (Fig. 1), is amplified by two TWTs (2, 3), which also serve as phase shifters, and is re-radiated by the transmitting antenna (4). A sawtooth voltage (with other types of phase shifters, it may have a different shape) is fed to the TWT coil (2) from the modulating voltage generator (5), the frequency of which changes in accordance with the voltage produced by the control voltage generator (6). This part of the circuit produces a normal type of radiated interference. The output voltage of the low-frequency noise generator (8) is fed to the noise voltage amplitude control device (7), which also receives the control voltage from the generator (6). At the beginning of each output cycle, the low-frequency noise voltage fed to the TWT (3) smoothly changes its amplitude from 0 to some preset value, the magnitude of which, generally speaking, can be changed. As a result of this sequence of operations, the jammer's output signal has the form shown in Figure 2. At the initial stage of deflection, the modulating noise amplitude is close to zero, and all the jammer's power is concentrated in the deflection signal. As deflection increases, the noise voltage amplitude increases, and some of the deflection power is converted into noise spectrum power, such that by the time the deflection reaches the deadband boundary, the signal reflected from the aircraft is completely masked by noise. The operation of protection circuits becomes impossible. As is known, the effectiveness of the diverting interference at the initial stage of diverting is determined by the ratio P yp /P ts , where P yp and P ts are the powers of the diverting interference and the target signal at the input of the radar receiving device (homing head). The proposed device ensures the maximum possible value of the ratio Р уп /Р ц at the initial stage of the withdrawal. After resolving the diverting jammer and target signals by frequency, the power of the diverting jammer can be reduced to further diverge the speed strobe, due to the absence of a reflected signal in the strobe. This is exploited in the proposed device, as the "freed" power of the diverting jammer is converted into background noise, masking the target signal. In general, various types of phase shifters, not just TWTs, can be used to create aliasing and background noise. Literature 1. Osipov, M.L., et al. "A device for protecting radio-technical equipment of a semi-active homing system with continuous radiation from speed-deflecting interference." "Problems of Special Radio Electronics," vol. 13, no. 22, 1966. 2. Rutskoy V.G., Polyakov N.T. Method of increasing the noise immunity of radio engineering systems from escaping int