This article examines the problem of implementing comprehensive protection for the population and critical infrastructure equipment from exposure to radiofrequency electromagnetic (RFEM) fields from 5G mobile communications equipment. This problem is relevant due to the expanding use of TDD pulsed mode in 5G systems. The article discusses the potential for providing such comprehensive protection for elements of the biosphere, which involves expanding the existing sanitary and hygienic certification system for transmitting radio facilities by defining protective zones and development restrictions based on the susceptibility of technical equipment to RFEM fields and hygienic regulation of the population’s susceptibility to TDD RFEM fields.

The effect of heat treatment (annealing) conditions in the range of 200–400 °C on the electrical resistivity, temperature coefficient of resistance, phase composition and structure of vanadium oxide films with a thickness of (100 ± 5) nm deposited on oxidized silicon substrates by pulsed magnetron sputtering has been studied. It has been found that annealing films at 200–275 °C in an environment of N₂ or O₂ makes it possible to form films with a linear dependence of resistivity on temperature in the range from 0.4 to 1.6 Ohm×cm with a temperature coefficient of resistance from –1.7 to –2.0 %/°C. Such films can be used in microbolometers with an operating temperature range of 25–85 °C. Annealing of films at 400 °C in an O₂ medium leads to a hysteresis dependence of their resistivity on temperature in the range from 0.9 to 2.9 Ohm×cm, with an absolute value of the temperature coefficient of resistance of 3.2–3.4 %/°C. The studied resistive properties are determined by the presence and quantitative ratio of the crystalline phases VO₂, V₂O₅, and VO_x formed during annealing.

A device structure for a superjunction insulated-gate bipolar transistor featuring a floating charge-carrier accumulation layer has been proposed and investigated via computer simulation. In this structure, the accumulation layer is shielded by an underlying p-type layer. It is established that the charge-carrier concentration within the accumulation layer does not affect the breakdown voltage. Furthermore, the proposed insulated-gate bipolar transistor structure demonstrates superior efficiency compared to conventional superjunction trench insulated-gate bipolar transistor’s, as well as those utilizing a floating p-region or an adaptive holeextraction path. Specifically, at an identical on-state voltage drop of 0.946 V, the turn-off energy loss of the proposed device is 75.38 % lower than that of a superjunction trench insulated-gate bipolar transistor with a floating p-region, and 52 % lower than that of a device with an adaptive hole-extraction path. Conversely, for a constant turn-off energy loss of 2.3 mJ/cm², the on-state voltage drop of the proposed device is 39.86 % lower than that of a standard superjunction trench insulated-gate bipolar transistor.

The article considers the synthesis of a binary radar recognition device in the absence of a priori analytical models of classification feature distributions. A methodology for sequential radar target recognition is proposed, based on the combined use of support vector machines and Wald’s sequential probability ratio test. At the training stage, a separating hyperplane is constructed, with respect to which the multidimensional feature space is transformed into a one-dimensional decision variable represented by the signed distance to the class-separation boundary. Based on the training sample, the conditional probabilities of correct and false recognition are estimated and used to form increments of the decision statistic. At the recognition stage, the statistic is recursively accumulated and compared with threshold levels until a decision is made. The methodology preserves a unified algorithmic structure when the feature set changes and allows adaptation through repeated classifier training.

Experimental Verification and Efficiency Analysis. The results of testing typical channel scenarios for visible light communication systems are presented. Heat maps of threshold parameters and algorithm efficiency are analyzed for the average data transfer rate and the number of switches for all scenarios. Experimental verification, conducted on the developed setup presented in Part 1, demonstrated an increase in the average data transfer rate in the range of 1.88 to 47.62 % relative to the classical threshold algorithm in all studied channel dynamics scenarios. The proposed algorithm reduces the number of modulation order switches relative to the classical threshold method in the range of 7.1 to 81.2 %, depending on the nature of the channel dynamics.

A discrete filter is examined for the joint estimation of the coordinates, velocity, and angular rate W of a target performing a steady turn, based on indirect (polar/spherical) radar measurements. When W is included in the augmented state vector, the increment conversion matrix becomes a nonlinear function of W itself; consequently, linearization – as employed in previously studied versions of the extended Kalman filter for indirect measurements – requires recalculating the Jacobian matrix at each step and introduces an additional methodological error. An unscented transformation of the augmented state vector is proposed to eliminate the need for linearizing the motion and measurement models. Monte Carlo statistical simulations (N_run = 545) were conducted to compare the proposed algorithm with its linearized counterpart across eight standard surveillance radar types (2D and 3D) and five target turn rates. The results demonstrate that the proposed algorithm yields a root-mean-square error for the W estimate that is, on average, 4.3 times lower (median 4.0; range 1.4–14.0 across all observation conditions) than that of the linearized extended Kalman filter, while offering a more modest improvement (averaging 1.2 times) in the root-mean-square error of the position estimate.

Instrumentation amplifiers, which are differential voltage amplifiers with high impedance at each input and a fixed gain, are widely used in various electronic equipment. The typical implementation of instrumentation amplifiers by connecting three operational amplifiers does not provide high voltage gain stability over a wide range of input common-mode signals, especially at high gain. To solve this problem, the design and circuitry features of precision instrumentation amplifiers from Analog Devices were studied. Based on the analysis results, the main blocks of instrumentation amplifier microcircuits with a single-supply voltage using bipolar transistors and junction field-effect transistors were developed. The article presents electrical schematic diagrams and circuit simulation results for all units, demonstrating the capability to program various combinations of parameters.

The possibility of using noise diodes as sensing elements of hot-wire anemometers was investigated. The dependence of the average value of the noise pulse amplitude on the temperature and air flow velocity was experimentally established for the ND102L and ND103L diode models. It was shown that, at a constant bias voltage corresponding to the breakdown voltage of the noise diode at the maximum temperature in the studied range, an increase in the cooling air flow velocity leads to a linear increase in the noise pulse amplitude. The sensitivity of the proposed method was determined to be 156.9 mV·s/m for the ND102L diode and 105.9 mV·s/m for the ND103L diode. A comparison of the amplitude method of velocity measurement with the frequency method was performed. It was found that the proposed amplitude method provides a lower error (4.5 % for ND102L and 2.1 % for ND103L), higher speed and simplicity of hardware implementation, which makes it promising for use in compact real-time measuring devices.

This paper considers the problem of increasing the accuracy of object distance determination in a video-centric self-organizing multi-robot system without odometry (POM-MRS) operating in a quasi-stationary mode. In modern POM-MRS, the tasks of detecting a reference agent for measuring the distance to an environmental object, network identification of the reference agent (establishing a correspondence between the agent’s image and its network address), and determining its orientation are solved using complex neural network detection. This limits the distributed stereo basis and results in relatively low accuracy of object distance measurements in large-scale open spaces. To improve the accuracy of environmental distance determination, we propose a model based on local consistent triangulation with an analytical assessment of measurement errors and protocol-geometric verification of agent detection hypotheses. The model reduces these errors compared to single-robot system models based on odometry and existing POM-MRS models based on complex neural network agent detection.

An analysis of post-processing circuits based on a linear feedback shift register is carried out. A modification of the random number post-processing circuit using a multi-input signature analyzer is proposed, which employs a time compression factor and a variable number of entropy sources. The influence of the circuit’s key parameters on the entropy of processed sequences and on the results of NIST 800-22 statistical tests is analyzed. The hardware costs of implementing the circuit on programmable logic integrated circuits are estimated, and a comparison with similar circuits is performed. The results confirm the circuit’s potential for use in energyefficient and area-efficient true random number generators.

The rapid growth of the internet of things ecosystem is constrained by the challenge of powering distributed sensor modules. Research has shown that attempts to harvest energy from standard Wi-Fi traffic are hindered by the low duty cycle of the useful signal, a consequence of the protocol’s random medium access mechanisms. To address this, the article proposes a two-stage approach. The first component is a software-reconfigurable transmitter based on the ESP32-S3 platform, designed to generate continuous-wave emission in the 2.4 GHz (ISM) band – an optimal choice for wireless power transfer. The second component is a multi-channel rectifying antenna (rectenna) featuring a controllable radiation pattern; beam switching is achieved using an ADG902 RF switch, while two patch antennas are arranged with orthogonal polarization. Experimental data confirm the effectiveness of the proposed solutions.

Conventional finite element analysis of the lumbar spine is strictly limited to the static geometry obtained via computed tomography with the patient in a static, supine position. Direct calculation of the stressstrain state for alternative physiological postures in real time is unfeasible due to high computational demands and the lack of computational meshes corresponding to various body positions (such as forward bending, lateral bending, or load-bearing) and loading scenarios. This article describes the development of a hybrid biomechanical approach that utilizes resting-state computed tomography data to predict changes in the stress-strain state resulting from variations in body position and loading conditions. Gradient boosting algorithms – specifically XGBoost and CatBoost – are employed to approximate the physical fields. The proposed approach enables the identification of zones with critical stress and strain concentrations during changes in body position and allows for the modeling of biomechanical states that are otherwise inaccessible to direct numerical analysis.