Noise generator. RU patent 2292109.

FIELD: radio engineering.

SUBSTANCE: proposed noise generator that can be used in small-size noise transmitters and data protection systems for blocking mobile telephone communications by generating masking noise has n amplifying components and two integrated feedback-interconnected multiple-resonant oscillatory systems.

EFFECT: enhanced high value of generated noise in broad frequency range at same mean noise power.

1 cl, 4 dwg

The invention relates to electrical engineering and can be used in small jammer and information security systems to block mobile phone by creating a masking noise.

Known broadband digital noise generator (Russia, author's certificate No. 2208289, IPC 7 H 03 In 29/00; 2003), which contains a clock generator, a shift register, modulo 2, the trigger circuit, the power amplifier, umerically diode and strip line.

The disadvantage of this device is the inability to obtain the noise signal at frequencies above 2 GHz due to the limited performance of digital circuits.

Known generator of the noise (Russia, author's certificate No. 2220508, IPC 7 H 04 To 3/00; 7 H 03 In 29/00, 2003), comprising a generator of high-frequency signal connected to the input of the power amplifier is operating in a nonlinear mode, and loaded on a non-Autonomous dynamical system in the form of parallel nonlinear oscillatory circuit, with parallel non-linear resonant circuit has an amplitude-frequency characteristic with hysteresis region.

The disadvantage of this device is the inability to obtain a noise signal with a wide and uniform spectrum due to the limited hysteresis area in the amplitude-frequency characteristic of the nonlinear parallel circuit.

The closest in technical essence and significant positive effect to the claimed solution is the source of the noise (Russia, author's certificate No. 292209, IPC 7 H 03 In 29/00, 1971), containing the n gain elements and the delay line, the sections of which form vnutrichasovye feedback amplifying elements, and the connection of the reinforcement elements of the delay line is made variable.

The disadvantage of this device is the dependence of the parameters of the delay line from the range of frequencies that it is not possible to obtain a noise signal at frequencies above 100 MHz and a bandwidth of more than 10 MHz.

The technical result of this invention is to improve the upper bounds generated noise in a wide frequency band while maintaining the average power of the noise and mass-dimensional characteristics of the noise generator.

The required technical result is achieved by the fact that in the known noise generator containing the n gain elements with variable connection, two United multiresonant oscillatory system, which are interconnected feedback, and one United multiresonant oscillatory system is connected to the inputs of the respective amplifier elements, and the other United multiresonant oscillating system to the outputs of the respective amplifying elements.

For the formation of the noise voltage in the desired range of frequencies is necessary to create a multi-frequency generation of independent harmonic oscillations and their components sum, while the cutoff frequency and bandwidth of the generated noise is determined by the parameters of the United multiresonant vibrating systems and their AC connection to the respective amplifying elements; average power and uniformity of the spectrum of the noise - the amount and type of reinforcing elements; physical specifications generator - size characteristics of the United multiresonant oscillatory systems.

Figure 1 shows the block diagram of the noise generator, figure 2 - equivalent circuit of the United multiresonant oscillatory system, figure 3 - photograph of practical realization of the noise generator, figure 4 is a spectrogram of the noise practically implemented generator.

The noise generator (see figure 1) consists of n gain elements 1.1, 1.n, the corresponding outputs are connected to first United multiresonant oscillatory system 2.1 and the corresponding inputs to other United multiresonant oscillatory system 2.2, which are connected feedback 3, while the connection of the reinforcement elements to the United multiresonant oscillatory systems 2.1, 2.2 is made variable, so that conditions are created multi-frequency lasing frequencies .

New in the realization of the noise generator is the use of two United multiresonant oscillatory systems 2.1, 2.2.

The equivalent circuit of the United multiresonant oscillatory system 2 is presented in the form of an electric line (coaxial, strip, waveguide of length L with the wave resistance W, short-circuited at the ends (0, 0′), in parallel to which increments ΔL in points 1...p...p n are connected amplifying elements 1.1....1.n (figure 2).

Structurally integrated multiresonant oscillatory system has the form of a closed loop, point, line, 0, 0′ short and have the same potential.

The sections of the power line L (i (ω k+1-i )L k+1-i (ω (i ) in relation to a connection point of the reinforcement element R can be considered as two quarter-wave short-circuited segment, equivalent to two parallel circuits with resonant frequencies ω i , ω k+1-i .

To obtain multi-frequency resonance in the frequency band parameters combined multiresonant oscillatory system 2.1, 2.2, derived in the course of the field experiment are determined by the ratios

The presence of the generator of n gain elements 1.1...1.n and two United multiresonant oscillatory systems 2.1, 2.2, covered by a frequency-dependent feedback 3 create conditions of generation k=2n - harmonic oscillations with step nastroyki frequency .

The advantage of combined multiresonant oscillatory system over other multiresonant oscillatory systems 2 that the number of generated frequencies twice the amplifying elements, the system is the joint that allows for simultaneous summation of the generated oscillations.

The presence of the United multiresonant oscillatory systems 2.1.2.2, n non-linear amplifier elements 1.1...1.n create conditions of mutual modulation amplitude, frequency and phase between the independent harmonic oscillations and the formation in the vicinity of frequencies ω i , adjacent spectra S(ω (i ) a band of frequencies Δω′ i , which in theory is confirmed by the conclusion of the Central limit theorem: the sum of a sufficiently large number (more than 5) uncorrelated harmonic oscillation forms a stationary ergodic random process, is close to normal (Ishonamanki "Radio circuits and signals", M: - Owls. radio, 1977, s).

The total spectrum of the noise has a specific structure that has the property of Delta-correlation with average power equal to the sum of the capacities (Shibasaki "Radio circuits and signals", M.: Higher school, 1988, s).

The unevenness of the total envelope of the spectrum of the noise is caused by the change in the quality factor of the resonant systems for the various connection points of the reinforcement elements, and is determined by the magnitude of the detuning frequency between adjacent harmonics

The most uniform range and high quality of the noise is obtained when the magnitude of the detuning frequency between adjacent harmonics, corresponding to the phenomenon of "partial entrainment" frequency (Dsplind "radio Transmitting devices", M.: Energy, 1974, p.77).

When the frequency detuning more bandwidth adjacent spectra Δω i >Δω′ i in the total spectrum formed failures.

When the frequency detuning less bandwidth "capture" in the total spectrum, there is a significant emissions.

Correction spectrum of noise from discrete to continuous, can be achieved by alternating the connection of the reinforcement elements 1.1...1.n to the United multiresonant oscillatory systems 2.1, 2.2, and in a small range by changing the parameters of feedback 3.

Depending on the frequency range as amplifying elements 1.1...1.n you can apply bipolar and field-effect transistors, as well as amplifying elements with negative resistance (Gunn diodes, tunneling), as the United multiresonant oscillatory system 2 - LC circuit, resonators with distributed parameters in the form of segments of coaxial and strip lines, waveguides. A specific embodiment of the generator of the noise depends on the desired range of frequencies, the spectrum and power of the generated noise.

The physical feasibility of the proposed noise generator is confirmed by conducting field experiments. The noise generator is made for meter range in the band 100-250 MHz on the amplifying elements 1.1 1.6.... - transistors CT A connected to the United multiresonant oscillatory systems 2 in the form of two closed paths of lengths of the strip lines, feedback 3 - capacitive, selection of energy made by autotransformer diagram (figure 3).

The spectrum of the generated noise shown in the picture 4. Power spectral density of the noise is 0.02 W/MHz, the irregularity of the spectrum of the noise - 20%.

Thus, the proposed noise generator in comparison with the prototype allows to generate uniform noise signal in any radio frequency in the desired frequency band while maintaining the average power of the noise and mass-dimensional characteristics, with cutoff frequency and bandwidth of the generated noise is determined by the parameters of multiresonant vibrating systems and their connection to the amplifying elements; average power and uniformity of the spectrum of the noise - the amount and type of reinforcing elements; physical specifications generator - size characteristics of the United multiresonant oscillatory systems.

The noise generator containing the n gain elements with variable connection, characterized in that it introduced two United multiresonant oscillatory system, which are interconnected feedback, and first United multiresonant oscillatory system connected to the outputs of the respective amplifying elements, and the second United multiresonant oscillating system to the inputs of the respective amplifier elements.