RU197903U1 - NOISE SIGNAL SHAPER - Google Patents

Abstract

The utility model relates to the field of computing. The technical result consists in increasing the linearity of the spectral density of the amplitudes of the noise signal. The noise signal generator comprises a noise generator, a first frequency selective circuit, a second frequency selective circuit, a first amplitude modulator and an analog adder, where the output of the noise generator is connected to the first inputs of the first and second frequency selective circuits, the output of the first frequency selective circuit the first input of the first amplitude modulator, and the output of the second frequency selective circuit is connected to the second input of the first amplitude modulator, the output of the first amplitude modulator is connected to the second input of the analog adder, the output of the analog adder is the output of the device, the second input of the first frequency selective circuit is the first control input , the second input of the second frequency selective circuit is a second control input, and a third frequency selective circuit and a second amplitude modulator are further introduced, the first input of the third frequency selective circuit connected to the output of the noise generator, output t a frequency selective circuit is connected to a first input of a second amplitude modulator, a second input of a second amplitude modulator is connected to an output of a second frequency selective 2 ill.

Description

The proposed utility model relates to techniques for generating radio signals and can be used in the development and modernization of noise generators for masking spurious electromagnetic emissions and pick-ups (PEMIN) emitted by information processing equipment; Stations of radio communication lines.

A device of a shaper of modulation noise signals (Kupriyanov A.I. Radioelectronic wrestling / A.I. Kupriyanov. - M.: University Book, 2013, p. 124, Fig. 6.7), including an amplitude modulator that generates an amplitude-modulated signal and noise generator. A harmonic signal is applied to the first input of the amplitude modulator. The output of the noise generator is connected to the second input of the amplitude modulator, to which a noise signal ξ _w (t) is supplied. The output of the amplitude modulator is the output of the device. In the shaper of modulation noise signals, the harmonic signal is modulated by a noise signal. As a result of this modulation, a noise signal is generated that includes the upper sideband (ƒ> ƒ ₀ , where ƒ ₀ is the frequency of the harmonic signal and ƒ is the current frequency) and the lower sideband (ƒ <ƒ ₀ ).

Signs of an analogue that coincide with the features of the claimed technical solution is the presence of an amplitude modulator and a noise generator.

The disadvantages of the analogue include the following. When a harmonic signal is modulated by a noise signal, a functional connection of the phases of the spectral components in the upper and lower side bands appears. In this regard, the side bands in the spectrum of the noise signal at the output of the amplitude modulator turn out to be correlated (Kupriyanov A.I. Radioelectronic Wrestling / A.I. Kupriyanov. - M.: University Book, 2013, p. 125, paragraph 4). In accordance with this, there is a fundamental possibility for effective protection against such a noise signal. In addition, one can note other shortcomings inherent in this modulator of noise modulation signals: firstly, the strong unevenness of the spectral density of the amplitudes of the noise signal in the vicinity of the frequency ƒ _{0 of the} harmonic signal, which follows from the spectrogram of the amplitude-modulated signal (Fundamentals of the theory of electronic warfare / Ed. NF Nikolenko - M .: Military Publishing House, 1987. - p. 111, Fig. 6.3, b); secondly, in the noise signal at the output of the shaper of modulation noise signals in the frequency range from ƒ ₀ -ƒ _Sh. to ₀ ƒ ₀ + ƒ _{Sh. there} will be no spectral components of noise (ƒ _{Sh.- the} lowest frequency at which there is a spectral noise component at the output of the noise generator), which is due to the principle of the formation of amplitude-modulated signals; thirdly, there is no adjustment of the width of the spectrum of the noise signal at the output of the amplitude modulator, which reduces the electromagnetic compatibility of such a device.

A device for interfering with radar stations is known (Patent 2217874 RU, IPC H04K 3/00, Blokhin V.P. (RF), Volodin A.V. (RF), Dyatlov A.P. (RF), Polyanichenko V.P. , publ. November 27, 2003). In this device, the noise shaper includes a balanced modulator, which is a type of amplitude modulator, in the output signal of which there is no spectral component of the carrier oscillation, and a noise generator. A harmonic signal is supplied to the first input of the balanced modulator from the output of the high-frequency amplifier, and a noise signal is supplied to the second input of the balanced modulator. A noise signal obtained by the modulation method and having a spectrum width sufficient to suppress the signal of the radar station is removed from the output of the balanced modulator.

Signs of an analogue that coincide with the features of the proposed technical solution is the presence of a balanced modulator and noise generator.

The disadvantages of the analogue include the following. As a result of modulation of the harmonic signal by a noise signal, there is a functional relationship between the phases of the spectral components of the upper and lower side bands of the amplitude-modulated signal. This leads to the fact that the side bands in the spectrum of the noise signal at the output of the balanced modulator are correlated (Kupriyanov A.I. Radioelectronic Wrestling / A.I. Kupriyanov. - M.: University Book, 2013, p. 125, paragraph 4). In accordance with this, there is a fundamental possibility for effective protection against such a noise signal. In addition, one can note other shortcomings inherent in this modulator of noise modulation signals: firstly, the strong unevenness of the spectral density of the amplitudes of the noise signal in the vicinity of the frequency ƒ _{0 of the} harmonic signal, which follows from the spectrogram of the amplitude-modulated signal (Fundamentals of the theory of electronic warfare / Ed. NF Nikolenko - M .: Military Publishing House, 1987. - p. 111, Fig. 6.3, b); secondly, in the noise signal at the output of the shaper of modulation noise signals in the frequency range from ƒ ₀ -ƒ _Sh. to ₀ ƒ ₀ + ƒ _{Sh. there} will be no spectral components of noise (ƒ _{Sh.- the} lowest frequency at which there is a spectral noise component at the output of the noise generator), which is due to the principle of the formation of amplitude-modulated signals; thirdly, there is no adjustment of the width of the spectrum of the noise signal at the output of the amplitude modulator, which reduces the electromagnetic compatibility of such a device.

Of the known technical solutions, the closest in technical essence to the claimed one is a noise signal shaper (Utility Model Patent 193698, IPC Н03В 29/00, H04K 3/00, Zemlyanukhin P.A. (RF), Ochirov Ts.V., publ. 11/11/2019 Bull. No. 32). The noise signal generator includes a noise generator, an amplitude modulator, a first frequency selective circuit, a second frequency selective circuit, a noise signal level setting unit, and an analog adder. The output of the noise generator is connected to the first inputs of the first frequency selective circuit and the second frequency selective circuit, the output of the first frequency selective circuit is connected to the first input of the amplitude modulator and to the input of the noise level setting block, the output of the second frequency selective circuit is connected to the second input the amplitude modulator, the output of the unit for setting the noise signal level is connected to the first input of the analog adder, the output of the amplitude modulator is connected to the second input of the analog adder, the output of the analog adder is the output of the noise shaper, the second inputs of the first and second frequency-selective circuits are the first and second inputs, respectively shaper noise signal for supplying control signals to the center frequencies of the first and second frequency selective circuits. The noise signal obtained by the modulation method is removed from the output of the noise shaper.

Signs of the prototype, which coincides with the features of the proposed technical solution, is the presence of a first amplitude modulator, a noise generator, a first frequency selective circuit, a second frequency selective circuit and an analog adder.

The prototype is characterized by the following disadvantages.

When generating a noise signal using the modulation method (amplitude modulation is used), despite the fact that narrow-band (quasi-harmonic) noise signals are used as the carrier wave and the modulating signal, which are generated by the first and second circuits, frequency-selective, the amplitudes of the spectral components of the noise signal decrease in the vicinity of the center frequency of the noise signal, which plays the role of a carrier oscillation. In the prototype, to overcome this drawback, a block for setting the noise signal level is used, which transmits noise from the output of the first frequency selective circuit to the first input of the analog adder. This makes it possible to superimpose the spectral components of the noise coming from the output of the first frequency selective circuit onto the spectral components of the noise signal obtained in the process of amplitude modulation, and partially solve the problem of equalizing the amplitudes of the spectral components of the noise signal at the output of the noise generator. However, the width of the noise spectrum at the output of the first frequency selective circuit is fixed and determined by the quality factor of the first frequency selective circuit. This leads to the fact that at the output of the noise signal shaper at frequencies close to the center frequency of the first frequency selective circuit, a decrease in amplitudes (spectrum unevenness) of the spectral components of the noise signal will be partially observed. This non-uniformity of the amplitudes of the spectral components of the noise signal will strongly manifest with an increase in the central noise frequency at the output of the second frequency selective circuit (control of the spectral width at the output of the noise shaper), since in this case the spectral densities of the amplitudes of the lower and upper side bands of the amplitude-modulated signal will move away from the center frequency of the carrier oscillation entering the first amplitude modulator from the output of the first frequency selective circuit.

The technical result of the noise generator is to increase the linearity of the spectral density of the amplitudes of the noise in a predetermined and adjustable frequency range in which the formation of the noise signal is carried out, with an increase in the width of the spectrum of the noise signal at the output of the device.

Evidence of a causal relationship between the claimed combination of features and the achieved technical result is given below.

To achieve a technical result, the following devices are additionally introduced into the known device: a third frequency selective circuit and a second amplitude modulator.

The technical result is achieved in that in the noise shaper, comprising a noise generator 1, a first circuit selective in frequency 2, a second circuit selective in frequency 3, a first amplitude modulator 5 and an analog adder 6, where the output of the noise generator 1 is connected to the first inputs of the first circuit frequency selective 2 and a second frequency selective 3 circuit, the output of the first frequency selective circuit 2 is connected to the first input of the first amplitude modulator 5, the output of the second frequency selective circuit 3 is connected to the second input of the first amplitude modulator 5, the output of the first amplitude modulator 5 is connected with the second input of the analog adder 6, the output of the analog adder 6 is the output of the device 9, the second input of the first frequency selective circuit 2 is the first input of the device 7 and serves to supply the control signal of the center frequency of the first frequency selective circuit 2, the second input of the second selective circuit frequency 3 is the second input 8 of the device and serves to supply a control signal for the central frequency of the second frequency selective circuit 3, a third frequency selective circuit 10 and a second amplitude modulator 4 are introduced, the first input of the third frequency selective circuit 10 being connected to the output of the noise generator 1, the output of the third selective circuit in frequency 10 is connected to the first input of the second amplitude modulator 4, the second input of the second amplitude modulator 4 is connected to the output of the second frequency selective circuit 3, the output of the second amplitude modulator 4 is connected to the first input of the analog adder 6, the second input of the third circuit selective in frequency 10 the third control input 11 and serves to supply a control signal for the central frequency of the third circuit selective in frequency 3.

The essence of the proposed device is illustrated by drawings.

In FIG. 1 is an electrical structural diagram of a noise shaper.

In FIG. 2 shows diagrams of the spectral components of the signals at the outputs of the second frequency selective circuit (FIG. 2, a), the first frequency selective circuit (FIG. 2, b), the third frequency selective circuit (FIG. 2, c) and the shaper output noise signal (Fig. 2, g).

The diagrams shown in FIG. 2, obtained by modeling one of the possible variants of the circuitry implementation of the noise shaper (Fig. 1). The simulation was performed using the Micro-Cap 9 circuit simulation program.

The noise signal generator comprises a noise generator 1, a first amplitude modulator 5, a second amplitude modulator 4, a first circuit selective in frequency 2, a second circuit selective in frequency 3, a third circuit selective in frequency 10 and an analog adder 6. The output of noise generator 1 is connected to the first the inputs of the first circuit selective for frequency 2, the second circuit selective for frequency 3 and the third circuit selective for frequency 10, the output of the first circuit selective for frequency 2 is connected to the first input of the first amplitude modulator 5, the output of the second circuit for selective frequency 3 is connected to the second inputs of the first amplitude modulator 5 and a second amplitude modulator 4, the output of the third frequency selective circuit 10 is connected to the first input of the second amplitude modulator 4, the output of the first amplitude modulator 5 is connected to the second input of the analog adder 6, the output of the second amplitude modulator 4 is connected to the first input of the analog adder 6 analog output torus 6 is the output 9 of the device. The second input of the first frequency selective circuit 2 is the first input 7 of the device and serves to supply the central frequency control signal of the first frequency selective circuit 2. The second input of the second frequency selective circuit 3 is the second input of the device 8 and serves to supply the second frequency control signal frequency selective circuit 3. The second input of the third frequency selective circuit 10 is the third input 11 and serves to supply a central frequency control signal of the third frequency selective circuit 10.

The noise shaper operates as follows.

In the noise generator 1, “white noise” is generated in the frequency range from very low to frequencies exceeding the operating frequencies of the inventive noise shaper. From the output of the noise generator 1, “white noise” is supplied to the inputs of the first circuit selective in frequency 2, the second circuit selective in frequency 3 and the third circuit selective in frequency 10. As the first circuit selective in frequency 2, the second circuit selective in frequency 3 and third Frequency selective circuits 10 can be used, for example, serial or parallel oscillatory circuits. The resonant frequencies of the first circuit selective in frequency 2, the second circuit selective in frequency 3 and the third circuit selective in frequency are equal to ƒ ₀₁ , ƒ ₀₂ and ƒ ₀₃ , where ƒ ₀₁ > ƒ ₀₂ , ƒ ₀₃ > ƒ ₀₁ . The quality factors of these frequency selective circuits are respectively equal to Q ₁ , Q ₂ and Q ₃ .

Then the frequency range in which the spectral components of the noise signal will be allocated at the level of 0.707 by the first circuit selective in frequency 2 will be equal to:

The frequency range in which the spectral components of the noise signal will be allocated at the level of 0.707 by the second frequency selective circuit 3 will be equal to:

For the third circuit, frequency selective 10, the frequency range in which the spectral components of the noise signal will be allocated at the level of 0.707 will be equal to:

Accordingly, for the first circuit selective at a frequency of 2 at a level of 0.707, the maximum and minimum frequencies (ƒ _{max. 1} and ƒ _{min. 1} ) are equal to:

ƒ _max . ₁ = ƒ ₀₁ + Δƒ ₁ ; ƒ _min . ₁ = ƒ ₀₁ -Δƒ ₁ .

For the second circuit selective at a frequency of 3 at a level of 0.707, the maximum and minimum frequencies (ƒ _max.2 and ƒ _min.2 ) are equal to:

ƒ _max . ₂ = ƒ ₀₂ + Δƒ ₂ ; ƒ _min . ₂ = ƒ ₀₂ -Δƒ ₂ .

For the third circuit selective at a frequency of 10 at a level of 0.707, the maximum and minimum frequencies (ƒ _max.3 and ƒ _min.3 ) are equal to:

ƒ _max . ₃ = ƒ ₀₃ + Δƒ ₃ ; ƒ _min . ₃ = ƒ ₀₃ -Δƒ ₃ .

The spectral noise components allocated by the first circuit of frequency-selective 2 noise are fed to the first input of the first amplitude modulator 5. The spectral noise components allocated by the third circuit of frequency-selective 10 10 are fed to the first input of the second amplitude modulator 4. The noise spectral components allocated by the second circuit of frequency 3 are fed to the second inputs of the first 5 and second 4 amplitude modulators.

In the first amplitude modulator 5, the output signal is formed by multiplying the input signals coming from the outputs of the first 2 and second 3 frequency selective circuits. In accordance with this, in the claimed device, each spectral component of the signal coming from the output of the first circuit selective in frequency 2 to the first input of the first amplitude modulator 5 will be multiplied with each spectral component of the signal coming from the output of the second circuit selective in frequency 3 to the second input of the first amplitude modulator 5. As a result, an amplitude-modulated signal is generated at the output of the first amplitude modulator 5, including the upper and lower side bands in the frequency range from ƒ _AM.H = ƒ ₀₁ -Δƒ ₁ -ƒ ₀₂ -Δƒ ₀₂ to ƒ _AM.B = ƒ ₀₁ + Δƒ ₁ + ƒ ₀₂ + Δƒ ₂ . As a result of this, the width of the spectrum of the noise signal at the output of the first amplitude modulator 5 is equal to:

Δƒ _AM = ƒ _AM.B -ƒ _AM.H = 2 (ƒ ₀₂ + Δƒ ₁ + Δƒ ₂ ).

You can see that the spectrum width of the amplitude-modulated signal at the output of the first amplitude modulator 5 directly depends on the resonant frequency of the second circuit selective in frequency 3. Thus, by supplying a control signal 8 to the second input of the second circuit selective in frequency 3, the amplitude of the spectrum is controlled -modulated signal at the output of the first amplitude modulator 5.

However, it should be noted that the spectral noise components of the lower and upper side bands will be located in the vicinity of the frequencies: for the lower side band this frequency is ƒ ₀₁ -ƒ ₀₂ , and for the upper side band this frequency is ƒ ₀₁ + ƒ ₀₂ . Then, when the frequency ƒ ₀₂ is greater than the frequency Δƒ ₁ -Δƒ ₂ , in the frequency range from ƒ ₀₁ -Δƒ ₁ + ƒ ₀₂ to ƒ ₀₁ + Δƒ ₁ -ƒ _{02 there} will be a sharp decrease in the amplitudes of the spectral components of noise at the output of the first amplitude modulator 5 .

To overcome this, the inventive device uses a third frequency selective circuit 10 and a second amplitude modulator 4. A signal from the output of the third selective circuit 10 is received at the first input of the second amplitude modulator 4. Resonant frequency ƒ _{03 of the} third selective circuit 10 is selected higher than the resonant frequency of the first selective circuit 2 by the value of (Δƒ ₁ -Δƒ ₂ ) / 2. Accordingly, the resonant frequency of the third electoral circuit will be equal to

The amplitude-modulated signals from the outputs of the first 5 and second 4 amplitude modulators are fed to the second and first inputs of the analog adder 6. Given the distribution of the spectra of the lower and upper side bands at the outputs of the first 5 and second 4 amplitude modulators, the output of the analog adder 6 is the spectrum of the lower side band the signal at the output of the second analog modulator 4 is located between the spectra of the lower and upper side bands of the signal at the output of the first amplitude modulator 5. This compensates for the decrease in the amplitudes of the spectral components of the noise signal in the frequency range between the spectra of the lower and upper side bands formed at the output of the first amplitude modulator 5, thereby ensuring the linearity of the spectrum of the noise signal at the output of the analog adder 6 and, accordingly, at the output 9 of the noise shaper.

The upper side band of the spectrum of noise generated at the output of the second amplitude modulator 4, at the output of the analog adder 6 and, accordingly, at the output of the noise shaper is located to the right of the spectrum of the upper side band of noise generated at the output of the first amplitude modulator 5. This allows you to expand the frequency band into which generates a noise signal at the output of the device 9, without violating the linearity of the spectrum and spectral density of the energy potential of the noise signal at the output of the inventive shaper of the noise signal.

Claims (1)

A noise signal generator comprising a noise generator, a first frequency selective circuit, a second frequency selective circuit, a first amplitude modulator and an analog adder, where the noise generator output is connected to the first inputs of the first and second frequency selective circuits, the output of the first frequency selective circuit with the first input of the first amplitude modulator, and the output of the second frequency selective circuit connected to the second input of the first amplitude modulator, the output of the first amplitude modulator connected to the second input of the analog adder, the output of the analog adder is the output of the device, the second input of the first frequency selective circuit is the first control the input, the second input of the second frequency selective circuit is a second control input, characterized in that a third frequency selective circuit and a second amplitude modulator are additionally introduced, the first input of a third frequency selective circuit being connected to a generator output noise, the output of the third frequency selective circuit is connected to the first input of the second amplitude modulator, the second input of the second amplitude modulator is connected to the output of the second frequency selective circuit, the output of the second amplitude modulator is connected to the first input of the analog adder, the second input of the third frequency selective circuit is third control input.

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