This article discusses the possible formats of signals of 5G mobile communication networks (NR, IMT-2020): configurations of the number of resource blocks and frequency shifts of subcarriers. modulation schemes, organizations of the physical level, as well as the broadband signals of these networks and, as a result, the need for introducing a margin on the linearity of the transceiver’s paths to eliminate distortion or the manifestation of blocking effects when the signal interferes with third-party means. We analyze the characteristics of the dynamic range of the signals from IMT-2020 ground mobile systems and make a conclusion about the noise-like signals. To find the ratio of the maximum amplitude to its average value and a given ratio not exceeded with a given probability, the Matlab mathematical models were used. We infer that the law of probability distribution of the module of the instantaneous amplitude of the 5G signals corresponds to the distribution characteristic of narrow-band radio noise. Based on the study, the peak factor of the signal of the IMT-2020 ground mobile systems for various variations is obtained and a sufficient level of power reserve is provided to ensure, with high probability, the transmission of the 5G signals through radio paths, eliminating signal distortion. The results of this study were applied in the examination of the electromagnetic compatibility of radio electronic devices of cellular mobile communications with existing and promising electronic means of civil and special purposes and in the study of the protection of ground satellite stations from the effects of radio electronic means of IMT-2020 cellular mobile telecommunication networks located at border territories.

The purpose of this work is to theoretically study the contact interaction of a pre-stretched flexible elastic tensile belt with a fixed pulley. The case of linear distribution of the specific pressure from the pulley on the belt along the length of the coverage arc is considered. For this case, an expression is obtained for the belt tension force distributed along the coverage arc. It is shown that for a flexible link in the form of a tape, there are two types of sections within the coverage arc: two symmetrically arranged sections of an elastically deformable tape corresponding to the sliding arcs, and a section of a non-deformable tape located between them. Under certain conditions, there is no non-deformable section of the tape, i.e. the tape is elastically deformed within the entire coverage arc, which in this case is a sliding arc. Theoretical studies of the contact interaction of an elastically deformable flexible link with a fixed pulley have revealed the effect of independence of the length of the sliding arc, i.e., the flexible link that is deformed in the coverage area, from the tension force. The length of this section is determined by the angle of coverage and the coefficient of friction for the flexible link and pulley materials. The results obtained add to the information about the mechanics of interaction of the flexible link with the leading and driven links of the belt drive and allow you to get additional information about the phenomenon of elastic sliding that occurs in these gears.

In this paper, we describe a method that allows one to realize highly efficient amplitude modulation of radiation at the output of electro-optical laser switches with two coupled resonators, in which electro-optical elements are located both in two split arms and in every arm of a multipath interferometer with combined channels with a control voltage 2 times lower than in existing laser switches. Moreover, the electro-optical elements located in the two split arms of a multipath interferometer with combined channels, with one passage of the light flux through the electro-optical element, must make the opposite controlled changes in the phase difference of the interfering light beams. Therefore, for such electro-optical switches with two coupled resonators the value of the required electric power will be, respectively, 2 times less than that of the existing ones, which significantly expands their operating frequency range. In this case, a laser switch with electrooptical elements located in the two split arms of a multipath interferometer has an asymmetric dependence of the output radiation intensity on the change in the phase difference of the interfering light beams relative to the zero value of the light intensity. A laser switch with electro-optical elements located on all arms of a multipath interferometer with combined channels has a symmetric dependence of the output radiation intensity on the magnitude of the phase difference of the interfering light beams relative to the zero value of the light intensity. In addition, due to the coherent summation of the amplitudes of the interfering light waves, such laser electro-optical shutters also have amplification of radiation with a resonant wavelength.

A composite material based on zinc oxide nanoparticles synthesized by the chemical hydrothermal method and a polymer insulated matrix of sodium silicate was obtained. Free zinc oxide nanoparticles were formed by heating an equimolar solution of zinc nitrate and hexamethylenetetramine with different pH values (3–5). Nanoparticles were introduced into an aqueous sodium silicate solution and applied on a silicon substrate by centrifugation. Using scanning electron microscopy, we studied the structure and morphology of zinc oxide nanoparticles on a silicon substrate in unbound state and after their introduction into the sodium silicate matrix. It was found that the obtained particles have a hexagonal crystal lattice and a bimodal size distribution. After introduction in the matrix of sodium silicate, only smaller zinc oxide nanoparticles with an average diameter of 45 nm remain in it. Studying of the photoluminesclence spectra of a composite material, including zinc oxide nanoparticles obtained at different pH values of the initial solution, showed the presence of exciton and defectrelated photoluminescence bands with intensity’s maximums located at 383 and 590 nm, respectively. Zinc oxide nanoparticles in the stabilizing matrix of sodium silicate exhibit a higher relative intensity of exciton photoluminescence than unbound particles. The highest value of the relative intensity of exciton photoluminescence was achieved for a composite material including zinc oxide nanoparticles synthesized at pH=3,35 of the initial solution. The resulting composite materials can be used in optoelectronic and photovoltaic devices, and as an optical medium of non-cavity lasers.

The purpose of the work is to confirm experimentally theoretical estimates for time complexity of operations of the string processing model linked with the metric space for solving data processing problems in knowledge-driven systems including the research and comparison of the operation characteristics of these operations with the characteristics of similar operations for the most relevant data structures. Integral and unit testing were used to obtain the results of the performed computational experiments and verify their correctness. The C \ C++ implementation of operations of the string processing model was tested. The paper gives definitions of concepts necessary for the calculation of metric features calculated over strings. As a result of the experiments, theoretical estimates of the computational complexity of the implemented operations and the validity of the choice of parameters of the used data structures were confirmed, which ensures near-optimal throughput and operation time indicators of operations. According to the obtained results, the advantage is the ability to guarantee the time complexity of the string processing operations no higher than O  at all stages of a life cycle of data structures used to represent strings, from their creation to destruction, which allows for high throughput in data processing and responsiveness of systems built on the basis of the implemented operations. In case of solving particular string processing problems and using more suitable for these cases data structures such as vector or map the implemented operations have disadvantages meaning they are inferior in terms of the amount of data processed per time unit. The string processing model is focused on the application in knowledge-driven systems at the data management level.

Currently, robot manufacturers usually use closed proprietary protocols, which significantly complicates the development and integration of new robots and complexes. We propose to use a standard sequence of requests and responses between the control server and the client (some steps may be skipped). The first and second steps are designed to check the availability of equipment when you first turn on the system or during connection setup. If the verification is successful, the сontrol server proceeds to the next step. The third and fourth steps stand for initial configuration and adjustment of remote control. In the fifth step, the digital control signal is transmitted from the control server to the robot. The signal transmits all the necessary information to control the robot device. The keys are string fields (up to 256 characters). At the sixth step, the control server receives a сontrol response - the structure of the data transmitted from the client (robot) to confirm data acceptance and return of additional parameters. To identify robots, we propose to classify them by type and designation and indicate available types of control. For a detailed description of the robot, the entire initialization scheme is used. The proposed methodology is intended to describe infrastructure and platform independent interaction, which allows it to be used in various types of robotic systems.

To implement natural language user interface and an intelligent answer to questions, the knowledgebased semantic model for Chinese language processing is proposed. The article gives careful consideration to the existing methods and various knowledge bases for natural language processing. The analysis of these methods has led to the conclusion that in natural language processing, the knowledge base is the most fundamental and crucial part. The knowledge base makes it possible to ensure processing of a natural language based on initially described knowledge and to explain the processing operations. By virtue of the analysis of various methods for constructing knowledge bases about the English and Chinese languages, an ontological approach to the Chinese language processing was proposed. The Chinese language processing model has two main aspects: the design of knowledge base about the Chinese language and the development of ontology-based knowledge processing machine. The proposed approach is aimed at developing a semantic model of knowledge on the Chinese language. As a stage in the implementation of the approach, I designed the ontology of the Chinese language that can be applied for further processing of the language. This paper considers the preliminary version of the ontology and the principle of building a knowledge base about the Chinese language. There are no uniform standards and evaluation system for designing an ontology. Expansion, refinement and evaluation of the ontology require further research.

The study is devoted to the research of the dependence of the processing results of photoresistive films on the silicon wafers surface in an ozone environment on the conditions and parameters of the process. The high oxidizing potential of ozone justifies the possibility of its use for removing organic films under atmospheric pressure. The experiments were carried out using the developed research bench, in which the mode and method of heating, as well as the method of supplying gas to the surface of the photoresist, were varied. Silicon wafers with a formed 1,35-μm thick masking photoresist film were used as experimental samples. It was found expedient that uniform heating of the plate over its entire surface can be achieved using a ceramic IR heater. When the ozone-air mixture was introduced into the center of the heated sample, the presence of the removed photoresist residues was observed, which was associated with a temperature drop in its surface area. To solve this problem, the computer models of the temperature regimes of the reaction volume elements were calculated. They showed that the scattering of the working gas flow over the surface of the silicon wafer would significantly increase the efficiency of photoresist removal, and with a good selection of the treatment regime it would ensure complete removal of the photoresist. The data obtained were experimentally confirmed by using an ozone-air mixture flow separator. Experiments were carried out to study the effect of the distance from the wafer surface to the working gas inlet on the photoresist removal rate. They showed that a decrease in the distance reduces the ozone loss due to thermal decomposition and, consequently, increases the material removal rate.

Adaptive broadband low-noise radio frequency amplifiers (ABLNRFA) are widely used in the construction of systems for protecting radio receiving paths from nonlinear damage in a non-stationary electromagnetic environment (EME). One of the promising focus areas on the creation of ABLNRFA is the development of devices in the class of circuits with switched networks. The creation of such devices has certain features, since, along with the need to ensure a low noise figure and digital control of the regulation characteristic, it is required to provide high linearity and a large dynamic range (DR) of the device. This paper presents the results of the logical-heuristic synthesis of ABLNRFA with an adaptively adjustable transducer gain, which changes due to switching of transformer feedback circuits. In order to check the functional and technical characteristics of the synthesized ABLNRFA and optimize its parameters, a model was developed and studied in the ADS environment. The proposed ABLNRFA technical solution provides a discrete (23, 14, 10 and 5 dB) wideband change in the transmission coefficient, while the DR for third-order intermodulation in terms of a 1 MHz band is 83, 92, 98 and 104 dB, respectively. A step change in the transducer gain in the circuit of the lossless feedback circuit developed by ABLNRFA avoids the accumulation of additional noise in the structure and provides a low-noise figure that does not exceed 1 dB. The technical characteristics of ABLNRFA allow one to adaptively increase the overload capacity of the radio receiving path with a proportional expansion of its DR in the conditions of non-stationary EME, and thus increase the efficiency of the level protection system against nonlinear damage to the receiving paths of radio communication, radar and radio navigation.

To determine the dielectric permittivity of materials in a wide frequency range with the automation of measurements and the necessary accuracy, measuring cells have been created to ensure the simplicity of the design of the waveguide path. In order to obtain information about the suitability of measuring cells based on irregular SHF waveguides for estimation of dielectric parameters of materials, we simulated the structure of electromagnetic field in the system consisting of two irregular waveguides and waveguide chamber placed between them using a three-dimensional electrodynamic simulation in Ansoft HFSS package environment. The distribution of the electric field was simulated when an empty polyethylene tube, a rod of fluoroplastic and a rod of textolite are placed in the measuring cell. It was demonstrated that high order modes fade out in irregular waveguide and do not affect the precision of obtained results, and significant edge effects were not detected. It allows one to utilize measuring cells based on irregular waveguides together with a scalar or vector network analyzer and using the partial filling of the waveguide method or the modified Nicholson – Ross – Weir method for measurements of dielectric permittivity  of materials. The results of modeling the dependence of the amplitude and phase of the reflection coefficient of the textolite and fluoroplastic on the frequency in Ansoft HFSS environment are given. The simulation results are compared with the results obtained experimentally. The frequency dependencies of  were obtained experimentally for test materials – textolite and fluoroplastic – in the frequency range of 25,95–37,50 GHz. The experimental data are in satisfactory agreement with the results of theoretical calculations and do not go beyond the boundaries specified by the measurement uncertainty.

The purpose of the work is to systematically analyze and generalize a high-precision measuring signal for assessing the security in leakage channels in high-level noise by discrete-quantized representation of speech signals using the principles of amplitude-pulse modulation. It has been established that time sampling and level quantization of high-speed high-quality speech signals for digitalization are the main sources of information leakage. It is shown that to determine the degree of information security for high-quality high-speed transmission in broadband information transmission channels, it is necessary to use a complex measuring (test) composite signal. Requirements for the measuring signal are determined by the features of the discretequantized representation of speech signals. It is proposed to use a periodic pulse sequence of a triangular shape as a measuring signal. The triangular measurement signal has an advantage over the harmonic signal in the quantization noise extraction process, since allows you to achieve higher accuracy when processing it. To assess the security of the channel due to pulse-amplitude modulation, a harmonic signal is used, formed from a periodic pulse sequence of a triangular shape by the Fourier transform method. The use of the proposed measuring composite signal makes it possible to establish its numerical dependence with the numerical value of the signal taken as normalized and compare it to make a decision about the security of the speech signal. The materials presented in the article are original and can be used to assess the security of the channels of leakage of speech signals converted into digital form. In addition, the results obtained make it possible to carry out further studies of the security of speech signals during their reverse conversion from digital form to the original signal.

The paper presents justification of a binder material for incorporating carbon particles into the interfiber space of electromagnetic radiation absorber. A method for carbon particles incorporation into a fibrous material has been developed. It is based on applying a carbon-containing nanocomposite to the fibrous material’s surface. Previously, the research of carbon particles incorporation into a synthetic material by using an aqueous solution were carried out, which ensured a uniform distribution of carbon particles in the material structure. However, the properties of the material have changed significantly upon mechanical deformation. Therefore, the carbon particles incorporation process was investigated using various nanocomposites obtained on the basis of mixtures of vinyl acetate polymer, or epoxy polymer, or surface-active substance with carbon black. Based on the results of electron microscopic analysis and the reflection and transmission coefficients frequency dependences in the frequency range 0.7–17 GHz, the efficiency of using a nanocomposite based on a mixture of surface-active substance and carbon black to create electromagnetic radiation absorbers was justified. Such electromagnetic radiation absorbers have the transmission coefficient value about –18 dB and reflection coefficient value about –12 dB in the frequency range 7–13 GHz. Carbon-containing electromagnetic radiation absorbers based on fibrous material have thickness less than 3 mm, properties of flexibility and resistance to mechanical deformation. It can be used in various fields, in particular for hiding objects from radio frequency reconnaissance or protecting equipment from external interference.

The aim of this work was to study the effect of the gas composition during sputtering on the electrophysical properties of vanadium oxide films deposited by pulsed reactive magnetron sputtering of a vanadium target in an Ar/O2 medium of working gases.

The dependences of the magnetron discharge voltage, deposition rate, resistivity, temperature coefficient of resistance (TCR), and the band gap of vanadium oxide films on the oxygen concentration in the gas mixture are obtained. It was found that amorphous films of vanadium oxide are formed during reactive magnetron sputtering. It is shown that the properties of the deposited vanadium oxide films have a strong dependence on the oxygen concentration in the Ar/O2 gas mixture, which is associated with the formation of a mixture of various intermediate vanadium oxides in the film. It was found that from the point of view of using vanadium oxide films as thermosensitive layers of microbolometers, the films must be deposited at oxygen concentrations in the gas mixture of 17 to 25 %. At the given oxygen concentrations without heating the substrates, vanadium oxide films with a resistivity (0.6–4.0)·10-2 Ohm·m, TCR 2.2–2.3%/°C and a band gap for direct transitions of 3.7–3.78 eV. The obtained characteristics make it possible to use these films as thermosensitive layers of microbolometers.