The influence of rapid heat treatment (450 °C, 7 s) on the electrical parameters of CMOS integrated circuits during the formation of ohmic contact between aluminum metallization and polysilicon is considered. The following volt-ampere characteristics of the dependence of drain current on voltage were chosen as the analyzed parameters of n- and p-channel transistors: at the gate when diode-connected; on the drain at different gate voltages; on the drain in the channel breakdown mode without applying potential to the gate. A comparison of these parameters was carried out with respect to microcircuits manufactured using standard technology (450 °C, 20 min) to form these contacts. Analysis of the results showed that the use of rapid heat treatment to form an ohmic aluminum-polysilicon contact can significantly improve the above characteristics of n-MOS and p-MOS transistors. From the current-voltage characteristics of n- and p-channel transistors it follows that in the region of gate voltages greater than 0.65 V, the drain current after long-term heat treatment is higher than after quick heat treatment. Analysis of the current-voltage characteristics of the drain current versus the drain voltage showed that the drain current when using long-term heat treatment is significantly higher than after rapid heat treatment. In this case, for long-term heat treatment, there is a decrease in the channel breakdown voltage only for n-channel transistors and an increase in the drain current in the region of more than 5 V for both n- and p-channel transistors. Such improvements occur by eliminating the formation of polysilicon conglomerates in the aluminum contact, significantly reducing the epitaxial recrystallization of silicon doped with aluminum on the silicon surface, as well as reducing the microrelief of the interface of this contact and reducing the growth in the size of contact windows due to the lateral interaction of aluminum with polysilicon.

Photosensitive silicon/barium titanate/nickel structures with undoped barium titanate and doped europium were synthesized using the sol-gel method. The current-voltage characteristics were studied under illumination with a xenon lamp, highlighting a monochromatic line in the range of 400–800 nm and in dark mode. The synthesized structures showed the presence of a photocurrent on the reverse branch of the current-voltage characteristics over the entire studied range of illumination wavelengths. The maximum reverse branch current for a structure with undoped barium titanate was achieved when exposed to radiation with a wavelength of 470 nm and was about 0.6 μA for a bias voltage ranging from 2 to 10 V. Doping barium titanate with europium leads to an increase in the photocurrent by 17–26 %.

Using scanning electron microscopy, the structures of the surface and internal regions of porous silicon obtained by anodizing heavily doped plates of single-crystal silicon with electron conductivity in a hydrofluoric acid solution at different current densities were studied. It is found that the porous silicon surface has dark gray and light gray pores, which differ in size and surface distribution density. Dark gray pores possess larger sizes, and their density is about 5–10 times less than that of light gray pores. Based on the cross-section imagery, it is shown that light gray pores correspond to underdeveloped channels of small depth, while dark gray pores are the entrance points of deep bottle-shaped channels passing from the surface into the depth of the silicon wafer. The equivalent diameters of light gray pores on the surface of porous silicon are 12–15 nm and are practically independent of the anodic current density. At the same time, the equivalent diameters of dark gray pores and average distances between their centers increase linearly from 15 to 35 nm on the surface and from 35 to 120 nm in the volume of porous silicon when the current density is increased from 30 to 90 mA/cm². The average thickness of silicon skeleton elements is about 3 nm on the surface and increases to 5–6 nm in the volume. By setting the density of the anode current, it is possible to obtain layers of porous silicon with different structural parameters. The obtained research results have practical significance for the formation of composite materials based on porous silicon, which can be used as a porous matrix for the deposition of metals and semiconductors.

The need of modern microelectronics in the development of technological processes for the formation of nanostructured layers puts forward the necessity of understanding the mechanisms of nucleation and growth of deposits. The article considers the features of the initial stages of electrocrystallization of coatings with tin and tin-copper and tin-copper-ultradisperse diamond alloys. The kinetic regularities of electrode processes were studied by the voltammetry method. Based on the experimental data, the nucleation parameters (nucleation energy, effective interphase surface energy, radius and volume of the nucleus) were calculated. SEM images were obtained and the features of the roughness of the coating surfaces after deposition for 10, 20, 30 and 60 s were studied. It was found that co-deposition of tin-copper alloys and tin-copper-ultradisperse diamond particles increases the value of the limiting current from 2.8 · 10^–2 to 5.0 · 10^–2 A/cm². With an increase in electrocrystallization over-voltage, the rate of nucleation increases and their size decreases, while fine-grained and dense deposits are formed. With an increase in the deposition duration, crystallites grow and gradually coalesce with each other, the value of the equivalent diameter of the grain coatings increases, respectively, for: Sn – from 1 ⋅ 10^–6 to 4 ⋅ 10^–6 m, Sn-Cu – from 0.3 ⋅ 10^–6 to 1.3 ⋅ 10^–6 m, Sn-Cu-ultradispersed diamond – from 0.9 ⋅ 10^–6 to 1.4 ⋅ 10^–6 m. The established patterns make it possible to control the structure of the coatings and obtain deposits with specified properties. The presented results may be of interest to specialists involved in the formation of solderable galvanic coatings.

One of the factors causing the failure of spacecraft integrated circuits is exposure to heavy charged particles. The entry of heavy charged particles into electronic devices leads to the appearance of single event transients (short current pulses), which in analog microcircuits manifest themselves in distortion of the output signal shape, and in digital microcircuits can cause a single event upset. The article discusses a technique for circuit mode-ling of the effect of heavy charged particles on bipolar analog microcircuits, including the developed equivalent electrical circuit of a bipolar transistor for LTSpice and the procedure for modeling transient processes. Despite the simplifications adopted, namely: failure to take into account the dependence of the duration of the rise and fall of the current pulse generated by a charged particle on the parameters of the transistor structure, the assumption that the entire charge is generated in the active base and the space charge regions of the emitter and collector junctions, an equivalent circuit has been developed made it possible to determine that the shape of the collector current pulse for circuit with a common emitter when exposed to a heavy charged particle is determined by the speed of the transistor and its operating mode. Using the developed methodology, the “critical” transistors of the two studied analog microcircuits were determined, and the need to bypass the current-setting resistors with a small capacitor was justified.

A technique has been proposed for predicting the average intensity of electromagnetic background created near the Earth’s surface by a constellation of communication satellites, taking into account the number of satellites in the constellation, the satellite total radiated power, parameters of its radiation in the main and side lobes, the orbit altitude and restrictions on the tilt angle of service of ground-based equipment. The results of the analysis of the dependence of the average electromagnetic background levels at the Earth’s surface on the number of satellites in the constellation under various scenarios for the implementation of information services for terrestrial subscriber terminals are presented, confirming the adequacy of the developed approach. It is concluded that the expected levels of electromagnetic background in the microwave range created by megaconstellations of low-orbit communication satellites are many orders of magnitude higher than the levels of electromagnetic background of natural origin, which significantly changes the physical characteristics of the habitat.

The inverse antenna aperture synthesis technology used to construct a radar image of an aircraft’s propellers has shown high efficiency. The radar image allows to visualize the blades of the rotors included in the functional group (traction rotors of an aircraft, rotors of a twin-rotor helicopter, rotors of a multicopter). In the case of a single rotor in an aircraft (an airplane’s tractor rotor, a single-rotor helicopter’s main rotor), the radar image is simple and clearly perceptible. In the case of several propellers belonging to the same functional group, the ana ysis of the radar image becomes significantly more complicated. This is due to the random relative position of the blades of different propellers at the moment the image begins to be constructed, as well as the possible random coincidence of the spatial position of the blades belonging to different propellers. In this regard, determining the number of propellers in an aircraft is a new urgent task, the solution of which allows us to obtain additional information for recognition. The method under consideration for determining the number of propellers is based on the most common design features – the blades in the propeller follow at the same angular interval, in the propellers of the functional group the number of blades is the same.

A method for estimating the orbital parameters of a nanosatellite-relay, implemented by measuring the total electron content in the ionosphere based on relaying GPS navigation signals at frequencies of 150/400 MHz, is substantiated. The method involves estimating the Cartesian coordinates of the nanosatellite-relay based on the results of measurements of the total ranges “navigation satellite – nanosatellite relay – ground receiving point”, obtaining estimates of the orbital plane inclination angle and the longitude of the ascending node using the least squares method, and estimating the remaining orbital parameters using the maximum likelihood method. Simulation results and accuracy characteristics of the proposed method are presented. It is shown that for a typical signal-to-noise ratio in the equipment of the receiving point and an observation time of the nanosatellite-relay of 600–800 s, the mean square errors in estimating the orbital parameters of the nanosatellite-relay are: for angular quantities – fractions of arc seconds, the semi-major axis of the ellipse – 4–5 m, eccentricity – 2–3 ppm.

Two algorithms for calculating the phase transformation, which consists in calculating the outputs of a chain of phase links, are considered. The algorithms are based on the idea of synthesis of a dual phase link, which allows calculating the outputs of a cascade of two-phase links in one pass. To synthesize dual phase links, the representation of digital filters by the space state method is used. The proposed algorithms are implemented in the C language, and they are compared with the direct form of implementation of the phase transformation. During the experiments, the speed of calculating the chain of phase links on a personal computer with an Intel Core i7-37700 processor was estimated using the profiler built into the Visual Studio environment. The results showed that both algorithms allow accelerating the calculation of the chain of phase links by 1.3 and 1.8 times, respectively.

The article considers types, functions and some features of cryptosystems, as well as circuit design options for expanding their functionality. Options for generating keys and ciphers used in cryptosystems with a typical structural organization, and technologies for creating encryption chains are presented. An encryption scheme is described, in the recurrent formula of the algorithm of which the previous blocks of both encryption and plaintext are used. This scheme reliably protects against any unauthorized modification of the encrypted text. Structural diagrams of the organization of symmetric and asymmetric cryptosystems are given. A variant of implementing a decoding procedure in a threshold MIMA cryptomodule for sharing a secret with a masking transformation is proposed, in which the necessary time and hardware costs for performing the procedure of reconstructing the original secret are minimized. The presented material can be the part of the original sections of a necessary and sufficiently provided in mathematical terms textbook on the basics and modern problems of cryptography.

Today, the issues of transferring private households to independent energy sources, including solar panels and solar collectors, are relevant. The article examines software options for hardware systems that can be used to manage energy supply systems for private homes. Technologies for using independent energy sources in the energy consumption system are presented, as well as the mathematical model for their optimization for remote country houses.

Existing and currently widely used data storage technologies are considered. It is noted that the growth in the volume of digital information resources at an astronomical pace has led to the rapid development of technologies for their creation, storage, and access to them. In the context of Industry 4.0, the use of digital technologies to create intelligent and interconnected production and data processing processes is of particular importance. Blockchain technology and cloud technologies have become integral components of modern digital transformation. Taking into account the current state of data storage and blockchain technologies, network capabilities, enterprise needs and other factors, the possibilities of selecting and using storage tools and technologies, principles of joint implementation and application of different technologies, as well as modern virtualization approaches and blockchain technology for solving distributed data storage issues have been explored.

The work of a network that implements algorithms for IT diagnostics of neurological diseases based on the Internet of Things technology has been developed and modeled. The network includes a smartphone, a platform, a neural network, and applications. First, the voices of sick patients are entered from the smartphone to train the neural network, and then the examined patients for IT diagnostics. Data is transferred between the smartphone and the platform (ThingSpeak) via the MQTT protocol. The smartphone’s mobile application extracts the voice functions of the examined patients and records them on the Internet of Things network platform. Recognition is performed using the trained neural network. The structure and algorithm of the ThingSpeak platform are presented. IT diagnostics data are displayed in the application on the smartphone. The patient data used in the study are taken from the ADReSS 2020 Challenge program, which contains speech data of patients with Alzheimer’s disease and healthy people.