RU2736330C1 - Transmitting communication complex of ultra-low frequency range - Google Patents

Abstract

FIELD: radio equipment.

SUBSTANCE: invention relates to communication equipment of ultra-low frequency band, and can be used for transmitting signals to deep-loaded and remote objects. Fundamental difference of the disclosed transmitting complex from the known in use electromagnetic field generation method, consisting in that each period of harmonic oscillation is divided into N pulses of rectangular shape of equal amplitude, the sum of which reproduces harmonic signal.

EFFECT: technical result consists in improvement of reliability of the system, as well as reduced dimensions of the used element base and emitting devices.

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Description

The invention relates to the field of radio engineering, in particular to communication technology in the extremely low frequency range, and can be used to transmit signals to deep and remote objects.

Known "Communication system of ultra-low-frequency and extremely low-frequency range with deeply submerged and remote objects", RF patent No. 2444766 from 20.03.2012

Known "Transmitting complex of communication of ultra-low-frequency and extremely low-frequency ranges with deeply submerged and remote objects", RF patent No. 2653110 dated 05/07/2018

The general disadvantages of the known systems and communication complexes of the extreme low frequency (ELF) range with deeply submerged and remote objects can be attributed to the following: - relatively low reliability, since failure of one of the elements of the radio transmission path leads to failure of the entire complex; - extremely large dimensions of the radio engineering elements of the path (capacitors, inductors) due to the large power passing through the path; - extremely large sizes of antenna feeder devices.

The aim of the invention is to increase the reliability of the ELF range communication complex, reduce the dimensions of the radio-technical elements of the path, and reduce the size of the antennas.

This goal is achieved by the fact that the transmitting communication complex of the extremely low-frequency range contains a central control panel with a microprocessor and 200 key amplifiers, each of which is loaded on a separate emitting element, while the current at the output of each key amplifier is equal to one two hundred of the current required to create the required voltage electromagnetic field by a transmitting complex.

FIG. 1 schematically depicts a possible variant of placement of the proposed transmitting communication complex, where the CPU is the central control panel, KU is the key amplifiers and the IE are the emitting elements. Also shown are the two-way connections between the CPU and the key amplifiers.

The work of the transmitting complex is carried out as follows.

The operation of the proposed transmitting complex is based on the well-known method for exciting electromagnetic waves (Method for exciting electromagnetic waves, RF Patent No. 2622620 dated 06.16.2017).

This method consists in the fact that each period of a harmonic oscillation is divided into N rectangular pulses of the same amplitude, the sum of which reproduces a harmonic signal (VF Dmitrikov, NB Petyashin, MA Sivers. Highly efficient shapers of harmonic oscillations. - Moscow: Radio and communication, 1988, pp. 20-21. VL Muravchenko, AN Balakhonov "Electrosvyaz" No. 3, 2014. Key formation of a harmonic signal, pp. 3-4), moreover, each pulse is formed one of N active elements operating in a key mode, with each active element loaded on one of N passive radiating elements. In this case, "it is not required to maintain the correspondence of the geometric dimensions of the emitters to the wavelength of the operating frequency" (the above-mentioned Patent No. 2622620).

Т=0,1 с, с - скорость света 3⋅10⁵ км/с.FIG. 2 graphically presents a method of generating a harmonic signal by the sum of rectangular pulses. The recommended value of N equal to 200 is determined from the condition of ensuring the level of higher harmonics is not more than -68 dB, which in most cases meets the requirements for electromagnetic compatibility of radio electronic means at the facility. The maximum distances between the key amplifiers should be much less than the minimum wavelength of the operating range corresponding to the maximum frequency. This makes it possible to minimize phase deviations between the vectors of magnetic induction, excited by the emitters of the key amplifiers. At a maximum frequency of 10 Hz, the minimum wavelength is 30,000 km. Thus, the maximum distance between key amplifiers and radiating elements that are maximally distant from each other should not exceed 300 km. In this case, the phase shift between the most distant amplifiers

T = 0.1 s, s - speed of light 3⋅10 ⁵ km / s.

From this it is seen that the phase shift Δϕ _max = 2π⋅10 ^-2 = 0.0628 is negligible.

The minimum distance between the key amplifiers will be determined by their design features and can be several tens of meters, which corresponds to even smaller values of Δϕ.

From the central control panel to the microprocessor included in it, information about the required operating frequency, class of radiation, a digitized information message intended for broadcasting, and the start time of work are received. In accordance with the data obtained, the microprocessor solves the problem of determining the time of turning on and off each of the two hundred key amplifier. For this, taking into account the given frequency and, accordingly, the oscillation period T, the pulse duration t _{n is} calculated for each n-th of two hundred (N = 200) key amplifiers using the formula:

The turn-on time t _n1 and turn-off time t _{n2 of} each key amplifier are counted from the beginning to each period of the harmonic oscillation and are calculated by the formulas:

The command on the time of switching on or off in digital form in the form of a code combination containing the digital address of the key amplifier is sent to the control buses of the key amplifiers, at the inputs of which there are digital-to-analog converters (DAC). If the code combination matches, the executive element turns on or off, in accordance with the received command, the n-th amplifier. Information about their health is transmitted from each key amplifier via control buses to the CPU.

An antenna with a low resistance should be used as a radiating element of each key amplifier in the complex to ensure maximum current in the antenna when the key amplifier is open. Taking this requirement into account, a loop of a highly conductive material (for example, copper) is proposed, which also has a low reactance R _X = ωL, taking into account the low values of the frequency ω and the magnitude of the inductance L in the ELF range with one loop in the antenna. The proposed emitter - a loop with a current must ensure the excitation of a magnetic field, the strength of which essentially depends on the value of the current passing through it. FIG. 3 is a schematic representation of a radiating element. FIG. 1 conventionally shows the lines of force of the magnetic field excited by the coils. The actual dimensions of all elements of the complex depend on the specific requirements for the transmission complex in all its parameters.

где: I - ток в одном витке; r - радиус витка; h - расстояние от витка, отмеренное в направлении перпендикулярном к плоскости витка. (Б.М. Яворский, А.А. Детлаф. Справочник по физике. - Москва: Наука, 1965, стр. 399).The intensity of the excited magnetic field by one turn of the n-th emitter can be calculated by the formula:

where: I - current in one turn; r is the radius of the loop; h is the distance from the turn, measured in the direction perpendicular to the plane of the turn. (BM Yavorsky, AA Detlaf. Physics Handbook. - Moscow: Nauka, 1965, p. 399).

As a result of the excitation of all two hundred radiating elements in the space surrounding the transmitting complex, a total magnetic field will arise. The strength of this field will change according to a harmonic law, in accordance with the change in the duration of the current pulses at the outputs of the key amplifiers. In accordance with the change in the magnetic field, the associated electric field also changes.

The use of two hundred key amplifiers allows, in the event of failure of one of them, to continue the operation of the transmitting complex with an insignificantly reduced power, which improves its reliability characteristics relative to the currently known complexes.

Thus, the proposed transmitting complex for communication of the extremely low frequency range of 0.1-10 Hz with deeply submerged and remote objects makes it possible to increase the reliability of the operation of such a complex, as well as to reduce the dimensions of the used element base and radiating devices.

Claims (1)

A transmitting communication complex of the extreme low-frequency range, characterized in that it contains a central control panel with a microprocessor and 200 key amplifiers, each of which is loaded on a separate emitting element, while the current at the output of each key amplifier is equal to one two hundred of the current required to create the required electromagnetic fields by the transmitting complex.

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