RU2097906C1 - Noise signal generator - Google Patents

Abstract

FIELD: radio engineering, electronics, in particular, protection of computer engineering equipment against information attacks using side electromagnetic radiation. SUBSTANCE: device has first and second interconnected self-exciting oscillators, first and second non-symmetrical strip lines and first capacitor, which are mounted in housing. In addition device has third non-symmetrical strip line, second and third capacitors, first, second and third resistors. Each self-exciting oscillator has two transistors connected into 2-cycle circuit with joined emitters. first, second and third non-symmetrical strip lines are designed as three-cycle Archimedean spiral. Bases of first transistors of first and second oscillators and bases of second transistors of first and second oscillators are connected in pairs to initial piece of first non-symmetrical strip line. Collectors of transistors of first and second oscillators are connected to initial pieces of second and third non-symmetrical strip line respectively. Ends of second and third non-symmetrical strip lines are joined and connected through second resistor to positive terminal of power supply, which is connected through fourth resistor to end of first non-symmetrical strip line. First capacitor is introduced between second and third non-symmetrical strip lines. Second and third capacitors are introduced between first and third non-symmetrical strip lines. EFFECT: increased width of signal spectrum, uniform spectral density of output power, increased reliability of noise generation. 2 dwg

Description

 The invention relates to the field of radio engineering and electronics and can be used to protect computer equipment (VT) and electronic equipment (REA) from information leakage as a result of spurious electromagnetic radiation, as well as in measuring equipment.

 An effective way to prevent information leakage from VT and CEA tools is to actively radio-technically mask side electromagnetic radiation using noise signal generators.

The most important requirements for noise generators of this kind are:
the broadband spectrum of the output signal, dictated by the wideband side electromagnetic radiation;
high uniformity of the spectral density of noise power;
stability of noise generation mode;
high efficiency;
small dimensions and weight.

 Known from the literature, noise signal generators do not satisfy the complex of these requirements.

 A known generator of noise signals with delayed feedback [1, Fig. 9.101] containing TWT as a nonlinear active element, a resonant filter and a delay line (LZ). Such a generator has large dimensions and mass. To supply it, a special power source is required, which also differs in large dimensions and weight. These disadvantages prevent the widespread use of generators of this type.

 More promising and more attractive in terms of size and weight, as well as in other respects, are semiconductor noise signal generators.

 A known noise signal generator [2] comprising a non-linear converter, LZ and a band-pass filter connected in a ring, while the non-linear converter is made in the form of a multistage amplifier with intra- and interstage feedback circuits through sections of the LZ, which is made of multi-tap of LC links.

 The disadvantages of this generator include a small efficiency, the instability of the mode of generation of noise signals when the supply voltage changes, poor uniformity of the spectrum.

 A noise signal generator [3] is also known containing a pump source in the form of a frequency-controlled self-oscillating block, a first inductance coil, a generator consisting of an element with negative resistance and an LC-oscillatory circuit formed by a second inductor and a nonlinear capacitor, as well as a coupling element. In this device, by providing random frequency control of the self-oscillating block, a certain improvement in the uniformity of the spectrum is achieved. However, the device is narrow-band and cannot be effective when used to prevent information leakage from VT and CEA.

 Closest to the claimed technical essence and a combination of essential features is the noise generator according to the invention [4] selected as a prototype. This generator contains [4, figure 2] the first and second interconnected oscillators, respectively, with the first and second asymmetric ring-shaped microstrip lines, a feedback capacitor, a microstrip output line with an isolation capacitor. Each of the oscillators is made on one bipolar transistor.

The disadvantages of the prototype include:
a relatively narrow spectrum of the output signal, limited from below due to the insufficient wide-width oscillatory system;
relatively low uniformity of the spectral power density of the noise signal;
low stability of the noise signal generation mode when the supply voltage changes.

 The objective of the invention is the expansion of the spectrum of the output signal while increasing the uniformity of the power spectral density and the stability of the noise signal generation mode when the supply voltage changes.

 The problem is solved in that the noise generator containing the 1st and 2nd interconnected oscillators installed in the screen body with the 1st and 2nd asymmetric strip lines of the NPL, the 1st capacitor, additionally contains the 3rd NPL, 2 3rd and 3rd capacitors, 1st, 2nd and 3rd resistors, while each of the oscillators is made on two transistors in a push-pull circuit with a common emitter, the 1st, 2nd and 3rd NPL are made in the form of a three-way spiral of Archimedes, the base of the first transistors and the base of the second transistors of the first and second oscillators are connected by Arno and connected to the initial section of the 1st NPL connected to the 1st terminal of the 1st resistor, the 2nd terminal of which is connected to the housing, the collectors of the transistors of the 1st and 2nd oscillators are connected to the initial sections of the 2nd and 3rd NPL, the ends of the 2nd and 3rd NPL are connected and through the 2nd resistor are connected to the positive input of the power supply connected through the 3rd resistor to the end of the 1st NPL, the 1st capacitor is connected between the 2nd and the 3rd NPL, the 2nd and 3rd capacitors are connected between the 1st and 3rd NPL, and the output of the generator is any point of the 2nd and 3rd NPL.

 The technical result of the invention consists in the multiple expansion of the spectrum of the output signal while increasing the uniformity of the spectral power density of the noise signal and the stability of the generation mode of the noise signal when the supply voltage changes. In particular, the overlap in the range in the proposed device is 100,000 times in comparison with 8 of the prototype.

 The achievement of the indicated technical result can be explained by the increase in the number of degrees of freedom in the proposed generator compared to the prototype due to the implementation of the NPL in the form of a three-way Archimedes spiral, the turns of which are inductively coupled to each other, the connection of the collectors of two pairs of transistors of oscillators with bases through the NPL and feedback capacitors and connection oscillatory system to a power source through a limiting resistor. As a result of this, a complex dynamic vibrational system is formed with super-deep positive feedback and a large number of vibrational circuits with different resonant frequencies and a chaotic change in these frequencies, as well as the phases of the onset and breakdown of high-frequency oscillations. The spectrum of the output signal of such a system is practically continuous in a wide frequency band, and the spectral power density has a high uniformity.

 A large number of degrees of freedom determines, at the same time, a higher stability of the noise signal generation mode when the supply voltage changes.

 In FIG. 1 shows an electrical diagram of the proposed device; figure 2 its amplitude-frequency characteristic (AFC).

The inventive device contains (figure 1): housing-screen 1; the first and second interconnected push-pull oscillators, made according to the scheme with a common emitter, respectively, on transistors 2, 3 and 4, 5 with the first NPL a ₁ b ₁ c ₁ d ₁ e ₁ , the second NPL a ₂ b ₂ c ₂ d ₂ e ₂ and third NPL a ₃ b ₃ c ₃ d ₃ e ₃ ; a first feedback capacitor 6 connected between the second and third NPL; second 7 and third 8 feedback capacitors included between the first and third NPL; the first resistor 9, one terminal of which is connected to the initial section a ₁ b _{1 of the} first NPL, and the other is connected to the housing; a second resistor 10, one terminal of which is connected to the positive input 11 of the power source, and the other terminal with the ends of the second and third NPL; a third resistor 12 connected between the end of the first NPL and the positive input 11 of the power source; a blocking capacitor 13 connected between the positive 11 and negative 14 inputs of the power source; isolation capacitors 15 and 16 for removing the output signals through the output level controller on the variable resistors 17 and 18.

The first, second and third NPLs form a three-way Archimedes spiral, while the bases of the first transistors 2, 4 and the bases of the second transistors 3, 5 of the first and second oscillators are paired and connected to the initial section of the first LPL at points b ₁ and a ₁ , the collectors of transistors 2 and 3 of the first oscillator are connected to the initial section a ₂ b _{2 of the} second NPL, the collectors of transistors 4 and 5 of the second oscillator are connected to the initial section a ₃ b _{3 of the} third NPL, the ends e ₂ and e _{3 of the} second and third NPL are connected to each other and connected to vyvo do resistor 10. Blocking capacitor 13 can be installed in the power source. An isolation capacitor 13 may be installed in the power source. The isolation capacitors 15, 16 and the noise level controller on the resistors 17 and 18 are shown in FIG. 1 as an example of a possible implementation of a device for removing the output signal of the generator. The output of the generator, in principle, can be any point of the second and third NPL.

 Each of the NPL is made in the form of a coil and, therefore, represents an inductance. Due to their location in close proximity to each other, all three NPLs are inductively interconnected. Capacitors 6 8 determine the electrical connection between the NPL, and these capacitors, on the one hand, provide feedback, and on the other are capacitors of oscillatory circuits. As a result, a complex oscillatory system is formed with a large number of oscillatory circuits and degrees of freedom, which determines the superdeep hard positive feedback in the circuit of self-oscillators. The distributed system also includes the distributed capacitance between the NPL and the housing. An oscillatory system is connected to a power source through a resistor 10, i.e. it is not purely reactive, but with losses.

 The operation of the proposed device is based on the principle of intermittent generation of high-frequency oscillations, repeated at low frequency. The root cause of the stochastic behavior of the system is the natural fluctuations of the initial conditions for the appearance of high-frequency oscillations, the amplitude of which due to the effect of super-regenerative amplification takes a significant increment, but does not reach a stationary value determined by the nonlinearity of the active elements, since the energy in both self-oscillators comes from one power source through a common resistor 10, limiting current of active elements. With the saturation of the active elements and the charge of the capacitors of the oscillatory circuits, there is a sharp decrease in the current through these elements, after which, due to the deep positive feedback, the capacitors of the oscillatory circuits discharge through the inductances of these circuits, which leads to shock excitation of the oscillatory circuits. Due to the inductive coupling of the NPL, this process extends to all oscillatory circuits and each of them creates high-frequency oscillations at a frequency determined by the parameters of this circuit. Due to the large number of degrees of freedom, the dynamic mode of operation of the generator is characterized by a chaotic change in the resonant frequencies of the oscillatory circuits and the phases of the beginning and end of high-frequency oscillations, which determines both the expansion of the spectrum of the output signal and the increase in the uniformity of the spectral power density of the noise signal. A large number of degrees of freedom provides at the same time high stability of the noise signal generation mode when the supply voltage changes.

 A prototype device was made on a printed circuit board of double-sided foil fiberglass 1.5 mm thick using serial elements (transistors, capacitors, resistors). Asymmetrical strip lines in the form of copper printed conductors had a width of 2.5 mm. The screen housing is made of metal and has dimensions of 75 x 100 x 15 mm.

 The graph of the frequency response of the prototype (figure 2) shows that the proposed device provides overlap in the range of 100,000 times with high uniformity of the spectrum.

 The noise signal generation mode remains stable when the supply voltage changes within 3.5 to 7 V.

 The industrial feasibility of the invention is visible from the description of the proposed device in statics and dynamics and is confirmed by the fact of manufacturing and successful testing of a prototype with the achievement of the specified technical result.

Literature
1. Neymark Yu. I. Land P.S. Stochastic and chaotic oscillations. M. 1987

 2. Auth. St. USSR N 292209, class H 03 B 29/00, publ. 01/06/71

 2. Auth. St. USSR N 1555804, class H 03 B 29/00, publ. 04/08/90

 2. Auth. St. USSR N 1806439, class H 03 B 29/00, publ. 03/30/93

Claims (1)

 A noise signal generator comprising first and second interconnected oscillators installed in a screen housing with first and second asymmetrical strip lines, a first capacitor, characterized in that it further comprises a third asymmetric strip line, second and third capacitors, first, second and third resistors, in this case, each of the oscillators is made on two transistors in a push-pull circuit with a common emitter, the first, second and third asymmetric strip lines are made in the form of a three-way sp Archimedes rails, the bases of the first transistors of the first and second oscillators and the bases of the second transistors of the first and second oscillators are paired and connected to the initial section of the first asymmetric strip line connected to the first output of the first resistor, the second output of which is connected to the housing, the collectors of the transistors of the first and second oscillators connected to the initial sections of the second and third asymmetric strip lines, respectively, the ends of the second and third asymmetric strip lines connected They are connected through a second resistor and connected to the positive input of the power supply connected through the third resistor to the end of the first unbalanced strip line, the first capacitor is connected between the second and third asymmetric strip lines, the second and third capacitors are connected between the first and third asymmetrical strip lines, and the generator output any point of the second and third asymmetric strip lines can serve.

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