RU38257U1 - RADIOMASKING DEVICE - Google Patents

Description

Radio masking device

The proposed utility model relates to radio engineering and specifically to the field of active radio engineering masking of secondary electromagnetic emissions and pick-ups (PEMIN) of computer equipment and control systems.

The spectrum of informative spurious electromagnetic radiation and interference from modern computers and peripheral devices occupies a frequency range from units of kilohertz to 1800 MHz 1, which is associated with an increase in the speed of modern computer technology. Interception of PEMIN is possible in the same frequency range at a distance of several hundred meters with a complete recovery of the information processed by the computer 2. In this regard, the issues of protecting information processed by computer technology from its leakage through physical channels remain relevant.

Traditional protection methods consist in minimizing emissions and interference of informative signals using filters, decoupling devices, screens, etc. In addition, motor generators are used to protect leakage information on the mains. Such protection methods give a positive effect, but there are difficulties associated with the installation, operation and periodic verification of additional elements of the protection system and its cost increases 3.

A device is known for protecting information processed by computer equipment from leakage through the side electromagnetic radiation channel 4, comprising a noise generator and a loop antenna, in which, by changing the configuration of the loop antenna, a uniform electromagnetic masking field strength is achieved in three orthogonal planes. The disadvantage of this device is that the energy spectrum of the masking signal is shifted to the low frequency region.

Of the known devices, the closest to the proposed technical essence is a radio masking device 5 containing a noise generator, a communication element, an active antenna circuit and a low-frequency noise source. The noise generator is made in the form of a system of two generators connected by a communication element, the first generator containing a nonlinear amplifier with inertial

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auto bias and delayed feedback circuit, the second generator contains a nonlinear amplifier and an adjustable feedback circuit, the output of the first generator is connected to the input of the second generator using a capacitive coupling element, and the active antenna circuit is made in the form of a radiating antenna, one end of which is connected to the output of the second generator , and the other with a common bus. To increase the stability of the radio masking device, a low-frequency noise source is introduced into it, the output of which is connected to the input of the first generator.

The disadvantage of this device is the low level of the masking signal at the top of the operating frequency range.

The technical problem, the solution of which the proposed utility model is aimed at, consists in expanding the frequency range of the radio masking device by increasing the level of the masking signal in the upper part of the frequency range. To do this, in a radio masking device containing a noise generator, a communication element, an active antenna circuit and a low-frequency noise source, the noise generator is made in the form of a system of two coupled generators, the first of which is a generator with delayed feedback and inertial auto-bias, and the second is made with adjustable feedback, the output of the first generator is connected to the input of the second generator using a communication element, the active antenna circuit is made in the form of a radiating antenna, one end of which is connected nen with output of the second oscillator and the other to a common bus introduced splitter, the output of the low frequency noise source connected to the input of the splitter, a first output connected to the input of the first oscillator, the second output of the splitter - to the input of the second generator.

The following drawings are presented as explanatory material:

FIG. 1. Functional diagram of the inventive device radio masking.

FIG. 2. The spectrogram of the output oscillations of the noise generator.

FIG. 3. The electrical circuit of the device specific implementation.

FIG. 4. Levels of masking and informative signals

A functional diagram of the inventive radio masking device is shown in FIG. 1. The device comprises a noise generator, which consists of a system of two connected generators 1, 2 and a capacitive coupling element 3 between them, a radiating antenna 4, a source of low-frequency noise 5 and a splitter 6.

The generator 1 contains a non-linear amplifier 7, a delay line 8 with a delay T and an inertial auto-bias circuit 9, the output of a non-linear amplifier 7 is connected to its input via a delay line 8, an inertial auto-bias circuit 9

is connected between the common electrode of the active element of the nonlinear amplifier 7 of the generator 1 and the common bus.

The generator 2 contains a non-linear amplifier 10 and an adjustable delay line 11, the output of the non-linear amplifier 10 is connected to the input through an adjustable delay line 11. The delay line 11 provides the ability to adjust the position of the natural frequencies of this generator. The output of the generator 1 is connected to the input of the generator 2 using a capacitive coupling element 3. The element of the oscillating system is a radiating antenna 4, one end of which is connected to the output of the generator 2, the other with a common bus.

The source of low-frequency noise 5 contains a source of noise voltage and amplifying - limiting device. The output of the low-frequency noise source is connected to a splitter 6, which contains one input and two outputs. The first output of the splitter 6 is connected to the input of the first generator, the second output of the splitter is connected to the input of the second generator.

The radio masking device operates as follows.

Generator 1 generates multi-frequency oscillations with spectral density maxima at natural frequencies, the interval between which is AFj l / Tj (where Tj is the delay time of the signal in the delay line of the first generator). The factors determining the complex dynamics of oscillations of the generator are the nonlinear properties of the active element, inertia and delay in the feedback circuit. There is a range of parameters at which the existence of regimes with chaotic dynamics is ensured in the generator.

Generator 2 generates multi-frequency oscillations with spectral density maxima at their own frequencies, the interval between which is DR2 1 / T2 (where 2

is the delay time of the signal in the delay line of this generator) and enriches the spectrum of oscillations of the system with additional frequency components with non-equidistant arrangement of natural frequencies with respect to the oscillations of the first generator. The avalanche multiplication of the combination components of partial generators and their nonlinear interaction through a coupling element leads to stochastization of the oscillatory process. Reducing the delay time of the T2 signal in the line

delay 11 allows you to expand the operating range in the region of high frequencies and thereby increase the level of the masking signal of the radio masking device

partial frequencies of oscillation of the generators, the magnitude of the connection between them and the level of external impact of 6.7. The influence of external low-frequency noise on generators 1 and 2 contributes to the destruction of synchronous oscillation modes and the formation of broadband noise, the band of which is determined by the passband of partial generators. Moreover, the effectiveness of the influence of external noise increases in the case of simultaneous exposure to both generators, which is characterized by normalization of the process and a decrease in the unevenness of the masked signal (Fig. 2). For this, a splitter is installed at the output of the low-frequency noise source, the two outputs of which are connected to the inputs of the first and second generators, respectively.

Thus, it is possible to expand the frequency range of the radio masking device and increase the level of the masking signal in the upper part of the operating range by reducing the delay time of the signal due to the feedback of the second generator, that is, moving the “natural frequency grid of the second generator using adjustable feedback in the region of more high frequencies.

As an example of a specific implementation of the claimed useful model, Fig. 3 shows a circuit diagram of a radio masking device that contains a noise generator, a communication element, an active antenna circuit, a low-frequency noise source, and a splitter.

The noise generator is a system of two coupled generators on transistors VT4 and VT5. The first generator on transistor VT4 contains a delay feedback circuit L1 (, 6ns), made in the form of a microstrip

lines, and inertial auto-bias circuit R11, Sat. The interval between the natural frequencies of this generator is 180 MHz. The second generator is executed on the transistor VT5 and contains an adjustable delayed feedback circuit L2, C7, C8 (,, 0ns). The interval between the natural frequencies of this generator may

adjusted when the capacitance of the capacitor C8 changes within the MHz. The connection between the generators is carried out using a capacitor C5.

As a low-frequency noise source, a UD1 noise diode is used, operating in the avalanche mode of the rn junction and a three-stage amplifier limiter on transistors VT1 - VT3. The noise source generates a noise signal in the frequency band from units of kilohertz to 6 MHz. From the output of the transistor VT3, the noise signal is fed to the input of the splitter, which is a microstrip line with taps, and then to the inputs of the oscillators 1,2 (from tapping 1 through the low-pass filter SI,

L4 to the input of the generator 1, from tap 2 through the low-pass filter SZ, L3 to the input of the generator

The loop antenna WA is included in the collector circuit of the transistor VT5 so that the full current of the transistor passes through the antenna. The properties of the antenna are weakly dependent on the frequency, which eliminates the frequency filtering of the signal and ensures the formation of a broadband noise electromagnetic field with a law of distribution of instantaneous values close to normal.

The use of a splitter and the simultaneous influence of an external low-frequency signal on the input circuits of coupled generators 1 and 2, as well as a certain selection of the time constant of the inertial mixing circuit R11, C6 and the delay time of the signals in the feedback circuits of these generators, allows us to expand the frequency range of the radio masking device from 100 kHz to 1800 MHz and increase the level of the masking signal at frequencies from 1000 MHz to 1800 MHz.

The power supply of the radio masking device is carried out from a DC source with a voltage of 12V.

Structurally, the prototype radio masking device, made in accordance with the claimed utility model, is a printed circuit board measuring 100 x 100x1.5 mm, which is located in a plastic case with a single-turn frame antenna with a diameter of 0.6 m fixed on it.

Measurements of the electromagnetic field radiated into the surrounding space by a prototype radio masking device show that the level of the masking signal is 10 -20 dB higher than the level of spurious emissions of computer equipment (Fig. 4) in the entire PEMI frequency range. At the same time, the operating range of the radio masking device, in comparison with the prototype, expanded to 1800 MHz, which corresponds to the regulatory requirements of 8 for active radio-technical masking (protection) of information at computer facilities of category 1-3. Currently mastered the mass production of radio masking devices made in accordance with the claimed formula of the utility model. References:

1. Anansky E.V. Information security is the foundation of business security. Security Service Magazine. Kiev. 2000, .№ 1-2.

2.Wim van Eyck. Electromagnetic iz.11 the study of video display modules: the risk of information interception // Information Protection Confident. 2001. No. 1, No. 2.

3. GOST R 50752-95. Information technology. Information protection against leakage due to spurious electromagnetic radiation during its processing by computer technology. Test methods.

4. Gorrokhovatsky A.N., Zapletin Yu.V., Bezginov I.G. “A device for protecting computer technology from electromagnetic spurious emissions. Patent. No. 2204882, Russia. Publication Date 2003.05.20.

5.Bezrukov V.A., Ivanov V.P., Kalashnikov B.C., Lebedev M.N. “Radio masking device. Patent No. 2170493, Russia. Publication Date 2001.07.10.

6. Lebedev M.P., Ivanov V.P. “Generators with chaotic dynamics. Instruments and experimental technique. Moscow, Nauka, 2002, No. 2, p. 94.

7.Kalyanov E.V., Ivanov V.P., Lebedev M.N. Forced and mutual synchronization of generators in the presence of external noise. Radio engineering and electronics. Moscow, 1990, Volume 35, Issue. 8.

8. The collection of standards for the protection of technical equipment from information leakage due to spurious emissions and interference. State Technical Commission of Russia, 1998

SCHUOZI

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Claims (1)

A radio masking device containing a noise generator, a communication element, an active antenna circuit and a low-frequency noise source, wherein the noise generator is made in the form of a system of two coupled generators, the first of which is a generator with delayed feedback and inertial auto-bias, and the second is made with adjustable feedback , the output of the first generator is connected to the input of the second generator using a communication element, the active antenna circuit is made in the form of a radiating antenna, one end of which is connected to the output ohm of the second generator, and the other with a common bus, characterized in that a splitter is inserted into it, while the output of the low-frequency noise source is connected to the input of the splitter, the first output of which is connected to the input of the first generator, the second output of the splitter is connected to the input of the second generator.