RU1841345C - Device for creating flickering interference and method for their formation - Google Patents

Abstract

FIELD: radio countermeasures.

SUBSTANCE: invention relates to the field of radio countermeasures and can be used in active interference stations of the relay type. The claimed device for creating flickering interference consists of a relay path, a selector for regular irradiation and a block for generating interference to selection channels. At the same time, a gain control unit and a time isolation modulator of the relay path are connected in parallel between the outputs of the regular irradiation selector and the inputs of the relay path the modulator of the time decoupling of the relay path. The claimed method of generating flickering interference consists in mutual protection of the system by re-emitting radar station signals by each protected object in flicker mode. At the same time, there is no interference, in the absence of the operation of selectors the triggers of the selectors of regular irradiation are used in the maximum gain mode, designed to affect the side lobes of the radiation pattern of the radar system, and create false marks of range or speed. When the selectors are triggered, the gain is reduced to a value sufficient to affect the main lobe, the switching of the path with a meander-shaped voltage is excluded and distracting interference is formed.

EFFECT: technical result is an increase in the probability of failure of tracking flickering targets by eliminating the loss of repeater output power when the protected object is irradiated with the main lobe of the tracking radar station (radar).

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Description

The proposed device and method for generating flickering interference relate to the field of radio interference and can be widely used in promising active interference stations of the relay type.

At present, the practical implementation of flickering interference with a large base for mutual protection of the aircraft formation encounters difficulties in creating repeaters with a large gain, since the real isolations between the input and output antennas on aircraft, with their wide radiation patterns, are in the range of 60 ÷ 90 dB , which is much less than the required gain (120 dB) to create flickering noise with a large base acting on the side lobes.

Proposed com. comrade Sergievsky B.D. and Fomichev K.I. "Method for decoupling the transmitting and receiving antennas of interference stations" by switching the relay path with a meander-shaped voltage with a period of T=2τ _ass. , where 2τ _ass. - the UHF signal delay in the relay path, although it theoretically provides any decoupling, however, leads to a loss in the output power of the jamming station of the order of 6 dB due to amplitude modulation and blurring of the signal spectrum. In addition, with the specified value of the required gain and the large range of input signals (about 75 dB) taking place, the repeater is oversaturated, sharply reducing its output power.

The purpose of the proposed device and method for creating flickering interference is to increase the probability of disrupting the tracking of flickering targets by eliminating the loss of the output power of the repeater when the protected object is irradiated with the main lobe of the tracking radar. This goal is achieved by changing the operating mode of the retransmission path and the shape of its output signal depending on the level of the input signal (activation of the threshold-type regular irradiation selector switched on at its input) in such a way that, at minimum levels of input signals coming to the input of the repeater from the side lobes The tracking radar, the repeater had a maximum gain, and when the protected object was irradiated with the main lobe, where it is necessary to have maximum power, the repeater would switch to normal operation with a gain factor of - K _c.o. , sufficient to create only distracting interference disruption of tracking (50÷60 dB).

When the protected object is irradiated with the main lobe of the radar radiation pattern, the power at the input of the jamming station

where P - radar power,

- коэффициент усиления передающей антенны РЛС,

- gain of the radar transmitting antenna,

λ - wavelength;

- коэффициент усиления приемной антенны станции помех,

- gain of the receiving antenna of the jamming station,

R - distance from the radar station to the protected object lies within - (45÷80) dB/W.

At the level of side lobes of the radar - (35÷40) dB, the values of the levels of input signals received at the input of the jamming station lie within - (80÷120) dB.

Required repeater gain for effective side-lobe action:

K _s.b. =K _c.o. ⋅K ₁ ⋅K ₂

where K _c.o. - gain of the repeater when operating on the main beam of the radar;

K ₁ - coefficient of suppression of the side lobes of the homing antenna (actually 20÷25 dB);

K ₂ - coefficient of suppression of the side lobes of the radar antenna.

Thus, K _u.b. =105÷125 dB.

With a gain of the relay path of 125 dB, the latter at P _out = 100 W will be saturated from the input signals - 105 dB / W or more. An increase in the input signal above the specified threshold will lead to a decrease in the gain of the path and, as a result, a decrease in the ratio of the signals received through the side lobes to the signal received through the main beam at the input of the GOS. Increasing the input signal (up to a maximum of -80 dB/W) will reduce this ratio to -25 dB. However, this worst-case ratio will still be within the scope of the MARU GOS scheme. Therefore, after resetting the tracking of a target located in the main lobe, the strobe of the speed or range of the GOS (or radar) should capture the signal coming through the side lobe with a distracting interference. A further increase in the input signal of the repeater is possible only if the protected object is accompanied by the main beam of the radar antenna pattern.

In FIG. 1 shows a block diagram of a device for generating flickering interference, placed on one of the protected objects of the system, which implements the proposed method.

The proposed device consists of a regular irradiation selector 1, a device for controlling the gain of the repeater 2, a repeater of the jamming station 3, a modulator that provides isolation of the repeater by modulating the path with a meander with a period of T=2τ _ass . - 4, interference generation devices for selection channels 5.

Selector regular exposure 1 is triggered by the input signal coming through the receiving antenna from the irradiating radar. The output of the regular irradiation selector is connected to the following inputs of the device for controlling the gain of the repeater 2 and the modulator 4. In turn, the outputs of these devices are connected to the corresponding modulation points of the path of the repeater 3. The device for generating interference to the selection channels 5 is also connected to the relay path.

At low levels of signals at the input of the repeater 3 coming through the receiving antenna of the jamming station from the side lobes of the radar (≤-80 dB/W), the selector 1 does not work. Gain Control 2 provides maximum repeater gain. The repeater in this case is modulated by the modulator 4, providing the necessary decoupling of the repeater by modulating the retransmitted signal with a meander with a period of T=2τ _ass . The device for generating interference to the selection channels 5 generates the desired signal at the output of the interference station - flickering false marks of the target.

When selector 1 is triggered (the protected object is exposed to the main beam of the radar radiation pattern), the following occurs:

- gain control device 2 reduces the gain of the relay path to the desired value;

- modulator 4 is disconnected from the relay path;

- the device 5 generates flickering distracting disruption noise.

Claims (2)

1. A device for creating flickering interference, consisting of a relay path, a regular exposure selector and a block for generating interference to the selection channels, characterized in that, in order to increase the energy potential of the interference station, parallel-connected a gain control unit and a time decoupling modulator of the relay path. 2. The method of generating flickering interference during mutual protection of the formation by re-emission of signals from the radar station by each protected object in the flicker mode, characterized in that in order to increase the energy potential of the interference stations of each object in the formation, the interference stations, in the absence of operation of regular exposure selectors, are used in the maximum mode gain, designed for impact on the side lobes of the radiation pattern of the radar system, and create false marks of range or speed, and when the selectors are triggered, the gain is reduced to a value sufficient to affect the main lobe, exclude switching of the path with a meander-shaped voltage and form distracting stall interference.

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