Introduction. An original approach to electrical circuit reservation, referred to as modal reservation (MR), is developed with the purpose of increasing the reliability and functional safety of radio electronic equipment (REA). A specific feature of this method consists in the use of strong electromagnetic coupling between the conductors, thereby increasing the reliability and ensuring the electromagnetic compatibility of the device under development. Printed circuit boards (PCBs) with MR are conventionally constructed using a structure designed to maintain mirror symmetry along the vertical, and, in some cases, along the horizontal axis. Meanwhile, asymmetrical options for PCB layouts with MR have not been previously considered.
Aim. To compare triple MR PCBs constructed using symmetrical and asymmetrical layout options to identify beneficial effects in the time domain.
Materials and methods. Simulations were carried out in the TUSUR.EMC software environment without considering losses in the conductors and dielectrics. A mirror-symmetrical four-wire transmission line with edge and broad-side couplings was selected as the initial triple MR design.
Results. No asymmetric sets of parameters that would attenuate the interference pulse of more symmetric sets (1 and 2) were found for all possible failure scenarios. However, sets 8, 9, and 12 allowed 2.38, 2.75, and 2.22 times higher ∆τ_min values to be achieved compared to set 1 (whose ∆τ_min value was greater than with symmetric set 2).
Conclusion. The discovered sets 8, 9, and 12 show that the arrangement w1 = w2 ≠ w3 = w4, s1 = s2 can be used to reduce the probability of pulse overlap on actual devices, as well as to implement shorter-length PCBs compared to the symmetrical option without the risk of pulse overlap. The data obtained can be used when tracing PCB layouts in situations requiring an increase in the delay difference.

Introduction. This paper presents a procedure for synthesis of phase-correcting elements (PCE) based on band-pass filter using specialized software developed for these purposes. The amplitude response of the synthesized PCE and LC-filters based on lumped elements is compared. The obtained structures can be applied in deflecting and focusing transmitarrays and in low-profile scanning antenna systems of ground terminals of satellite communication systems, which is particularly significant for the advancement of satellite communications used by medium- and low-orbit spacecrafts.
Aim. Software development for PCE synthesis based on band-pass filters (BPF) for application in deflecting and focusing transmitarrays.
Materials and methods. The filter characteristics were calculated using the MATLAB, Filter Solutions, and AWR DE software applications. Characteristics of the synthesized PCE were obtained by electrodynamic modeling using the finite element and finite integration methods.
Results. BPF were calculated in different software applications according to the given characteristics: center frequency – 10 GHz; bandwidth – 40%; and irregularity in the bandwidth – 0.1 dB. A software environment for synthesis of PCE was developed based on Chebyshev filters of type 1 of even and odd orders from 3 to 9. A satisfactory match between the characteristics of the coupled resonator filter and PCE was obtained. The deflecting and focusing structures were synthesized, and their electrodynamic modeling was carried out. The slope angle of the radiation pattern of the deflecting structure was 20º. The reflection coefficient of the focusing structure ranged within 10.7…12.7 GHz, not exceeding –15 dB. The directivity coefficient varied from 25.8 to 28 dB.
Conclusion. The synthesized deflecting and focusing structures can be used both independently and as control layers in low-profile scanning antenna systems. The developed software provides a significant reduction in the time required for the calculation and synthesis of a large number of PCE.

Introduction. Wireless sensor networks can be used to solve various economic problems, including detection of objects (phenomena) of interest. Most of the well-known information processing algorithms in such networks are built according to a radial architecture. Such an approach assumes each sensor to have a direct access to the central node responsible for making the final decision. At the same time, this approach cannot always be implemented in practice, largely due to the complicated topography of the area. In this connection, the development of an integrated detection algorithm for sequential transmission of information from sensor to sensor is a relevant research task. This algorithm will contribute to improving the efficiency of decision making, extending the detection area and increasing the operation duration of the power sources of sensors.
Aim. Synthesis and analysis of an integrated algorithm for object detection in wireless sensor networks with a linear topology.
Materials and methods. The detection algorithm was synthesized based on the statistical theory of optimal signal detection and, specifically, on the following a priori information: the probability of errors in the detection of each sensor object and the probability of errors in communication channels. The efficiency of the synthesized algorithm was evaluated numerically in the MATLAB environment.
Results. An algorithm for integrated detection of objects in wireless sensor networks was proposed. The efficiency of the developed algorithm was evaluated and the influence of such parameters as the signal/noise ratio and the number of sensors in the system on the detection efficiency was analyzed.
Conclusion. The analysis of the synthesized algorithm can be performed with sufficient accuracy, with the algorithm parameters and the probability of errors when moving from sensor to sensor being determined by fairly simple recurrent expressions. Future research directions should address the influence of communication channels with fading and scattering on the detection efficiency, as well as the development of integrated detection algorithms with unknown target coordinates.

Introduction. Deep convolutional neural networks are effective tools for classifying objects on radar images; however, their decision-making process is not transparent. This makes the determination of classification features of objects that affect the entire network operation a relevant research task. Such a study contributes to the field of explainable AI (XAI).
Aim. Determination of the classification features of military objects, detected by a deep convolutional neural network during training.
Materials and methods. The convolutional neural network was designed, trained, and tested using Keras and Tensorflow 2.0 libraries on the open part of the MSTAR dataset. The GradCAM method was used to visualize and determine the classification features of objects in the dataset.
Results. When using MSTAR images with an unsuppressed background, the object itself makes a significant contribution to the classification result only for 58 % of the images. For 6 % of the images, the classification result is determined by the object radar shadow, and for 25 % of images – by the background. For 11 % of the images, the most significant classification feature could not be established. For images with a suppressed background, in 60 and 40 % of the cases, brightness distribution and the object contour, respectively, made the main contribution to the classification result.
Conclusion. In the MSTAR dataset, each class of objects is represented by a set of radar images of the same real object from different view angles. This determines local background features, invisible to humans and unique to each class of objects. These features have a significant effect of the training outcome of the neural network. This effect can be eliminated by suppressing the background and reducing the image dimensionality. The obtained results also suggest the feasibility of further research into the XAI capabilities in relation to modern neural detectors and radar image datasets.

Introduction. The growing power of modern electronic devices imposes stricter requirements on their cooling systems. One promising cooling method employs the electrocaloric effect as the most accessible and simple phenomenon among all caloric effects to implement. However, thermal hysteresis near the phase transition point negatively affects the magnitude of the electrocaloric response and the cooling efficiency. Another important factor is the requirement for environmental friendliness of the devices, which makes the use of lead-containing compounds undesirable despite their pronounced electrocaloric effect. A possible alternative to such materials comprises solid solutions based on barium titanate; however, their temperature hysteresis phenomena are poorly studied.
Aim. Investigation of temperature hysteresis phenomena in ferroelectric ceramics.
Materials and methods. The samples under study were placed in a liquid thermostat to undergo a heating and cooling cycle at a given rate. The value of temperature hysteresis was calculated from the temperature dependencies of dielectric permittivity. The average grain size was estimated using SEM images of the sample surface.
Results. The influence of synthesis processes on the structure and grain size of ceramic barium titanate, as well as its dielectric properties, were studied. Temperature dependencies of the grain size of barium titanate and the porosity of sintered samples were studied experimentally. The temperature range of effective sintering above 1320 °C was determined. Dielectric characteristics of the samples at heating and cooling were studied. The parameters of temperature hysteresis and dielectric properties were determined. Changes in the value of temperature hysteresis were shown to be associated with changes in the grain size of barium titanate and the contact area between the grains.
Conclusion. An assumption about the optimal temperature of sample sintering was made. At this temperature, the material exhibits sufficiently good dielectric properties at a low temperature hysteresis.

Introduction. Thermal field treatment (TFT) of MOS structures causes instability of the threshold voltage associated with the transport of mobile ions of alkaline earth metal impurities (mainly Na⁺) in the electric field of the gate dielectric. Experimental kinetics of accumulation and restoration of the mobile charge during TFT deviate from the known descriptions by Snow’s diffusion and Hofstein’s boundary capture models.
Aim. Development of a quantitative model for the behavior of MOS structures during thermal field treatment in the modes of accumulation and restoration of the mobile charge of an ionic impurity.
Materials and methods. The model is based on the analysis of the capture kinetics of mobile impurity ions on polyenergetic traps in the volume of an amorphous gate dielectric. Following the analysis of physical processes, a system of differential equations is compiled and solved by the finite difference method using explicit and implicit difference schemes.
Results. The conducted comparison of the data calculated by the developed model and the experimental data reported in literature for the time dependencies of the threshold voltage shift of MOS structures with positive and subsequent negative gate bias determined the range of binding energies, the characteristic dispersion energy, the concentrations of impurity ions and traps near the gate and the silicon substrate, and the width of the region of their localization. A decrease in the range of binding energies in the vicinity of the SiO₂–Si interface compared to the SiO₂–metal gate interface was found, which may indicate the presence of an ordered thin SiO₂ layer in the vicinity of silicon.
Conclusion. It was shown that the charge recovery process occurs at a higher rate than the accumulation process due to the difference in the distribution of traps in the vicinity of the interphase boundaries of SiO₂ with the silicon substrate and with the gate. The proposed model can be used to describe the experimental asymmetric behavior of MOS structures contaminated with alkaline earth metal ions during TFT.

Introduction. Aperiodic order offers the possibility of creating new materials and structures with nonstandard properties. Active research is currently underway to obtain materials from non-atom building blocks, materials and elements based on aperiodic deterministic structures, photonic crystals and quasicrystals, and metamaterials. In the absence of natural analogues, the development of theoretical principles for the targeted rational design of their structures plays an important role. An important requirement consists in combining subunits and building blocks into a complex hierarchical nanostructure such that the local order would change only slightly when passing through interface regions. A possible solution to this problem is epitaxial matching between individual layers of the nanostructure. More complex structures are built on the principles of modular design. Previously, the principles of modular design have not been applied to quasicrystalline structures.
Aim. Apply the general principles of modular design to hierarchical structures containing quasicrystalline blocks.
Materials and methods. The structure of icosahedral quasicrystals was studied by computer simulation within the unit cell concept. The modular design of interfaces was based on the preliminary construction of a 3D icosahedral packing followed by cutting out those 2D fragments that intersect along common chains of equivalent nodes. The layers cut from quasicrystalline packings perpendicular to the symmetry axes of the icosahedron contain structurally similar fragments of identical subunits, separated by alternating long and short spaces in accordance with the LS Fibonacci sequence. Projection of icosahedral structure elements onto a kinked surface provides a coherent cross-linking of fragments with different symmetries by using the modular design of nanostructures from quasicrystalline blocks.
Results. The possibility of coherent cross-linking of fragments with different symmetries, which appears to be incompatible from the standpoint of classical theory, using the modular design of nanostructures from quasicrystalline blocks is confirmed.
Conclusion. Examples of cross-linking of alternating layers with 2, 3, and 5-fold symmetries into a single hierarchical nanostructure without a significant violation of the local order when passing through interface regions are presented.

Introduction. The current trends in the development of electronics require miniaturized devices with increased performance at affordable costs. The introduction of nanoscale structures and layers based thereon, including island structures, offers great opportunities for the development of various branches of electronics. Island thin films and nanostructures (INS) are thin-film structures whose formation has been completed at the initial stages. The size of the islands does not exceed 100 nm in the lateral and vertical directions, which makes the INS arrays to exhibit dimensional effects (electrical, magnetic, optical, mechanical, etc.). The formation of a composite dielectric layer with embedded conductive INS presents particular interest.
Aim. Development of a technique and testing of formation modes of a composite coating with INS.
Materials and methods. The research was carried out at the Department of Electronic Technologies in Mechanical Engineering of Bauman Moscow State Technical University. The research materials alumina and copper. A MVTU-11-1MC vacuum unit, equipped with magnetron and ion sources, was used as technological equipment. The roughness of the substrate and coating surfaces was studied using a Solver NEXT atomic force microscope; the geometric parameters of the composite layer were studied using a CROSSBEAM 550 scanning electron microscope.
Results. The average absolute deposition rates for copper and alumina were 25.9 and 0.3 nm/min, respectively. A conductive insert with a diameter of 25 mm and a width of 0.46 mm was used to form a composite structure with a diameter of 100 nm and a distance between the islands of 3…5 nm. To obtain a homogeneous structure and a high-quality adhesion of the composite layer to the substrate, preliminary ion treatment of the substrate for 120 s was required.
Conclusion. The developed method for forming a composite coating with INS involves the use of a combined target. The results obtained can be used when creating composite thin-film coatings from dielectric and conductive nanoscale structures by magnetron sputtering in vacuum.

Introduction. The article addresses the problem of creating an automated system for data collection from heat metering units, as well as a digital twin of such a system. Digital twins are widely used in the energy sector to optimize the operation of thermal power plants, including their timely maintenance, forecasting various emergency scenarios, or planning thermal energy production. Practical examples of such systems are presented. The relevance of this work lies in the possibility of predicting the size of pipeline defects based on both measurement and digital twin data.
Aim. Development of a distributed information and measurement system for heat supply monitoring with the introduction of a digital twin.
Materials and methods. The parameters of the heat-carrying agent, such as temperature, pressure, and flow, were simulated according to the normal distribution law and the thermal schedule of power plants. This information was further used to develop a mathematical and algorithmic support for predicting the state of technological equipment. The depth of a cavity defect which may occur in the pipeline was predicted. The strength condition was used as a criterion for the failure limit state. To determine the ultimate strength of the pipe wall, OST 153-39.4-010–2002 and the Barlow formula were used.
Results. The obtained results include a digital twin of the heat supply control system, the structure of a distributed information and measurement system for the unit of heat supply monitoring, algorithmic and software systems for the operation of the distributed information and measurement system and for predicting the failure state of the pipeline. The software operability was verified in normal operation and in the absence of access to the server.
Conclusion. The use of digital twin technology in heat supply monitoring makes it possible to optimize the thermal graph of the object by simulating the optimal values of the heat-carrying agent based on environmental parameters with an error in modeling the water temperature in the supply pipeline of Δt = ±5°C at ambient temperatures from –8 to +3 °C.