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The object of research is the process of radiation of electromagnetic waves from a flexible antenna-wristband. The subject of research is the wave parameters and directional properties of a flexible antenna-wristband. The existing problem is that it is necessary to ensure the electromagnetic compatibility of the radio frequency units of the wrist-worn infocommunication device. This problem is due to the fact that LTE/NB-IoT, Bluetooth/Wi-Fi, and GPS antennas must be placed inside the small-sized case of the infocommunication device. To solve this problem, let’s propose a simple and cheap version of a broadband flexible bracelet antenna for LTE networks, located outside the device case. As a basis for the development of a flexible antenna-wristband, the authors chose a patch antenna, which is the base of the theory of microstrip antennas. This is due to the fact that the theoretical material is well developed for the calculation and study of the patch antenna. Structurally, a patch antenna consists of an upper metal layer that emits electromagnetic waves, a solid dielectric base, and a lower metal layer that acts as a reflector. With the classical approach to constructing a patch antenna, the width and length of its upper layer are commensurate, and its lower metal layer has geometric dimensions much larger than the upper metal layer. In contrast to the classical design, the authors proposed a new shape of the patch antenna, in which the length of the upper layer of the radiation surface is much greater than its width (5–6 times), and the lower metal layer has dimensions slightly larger than the dimensions of the upper layer. The authors have developed a flexible antenna-wristband for the frequency range of 800–1300 MHz with a wave impedance of 50 ohms, 118.7×23 mm of the upper metal layer, and 124.7×25 mm of the lower metal layer. The length of the microstrip feed line of the antenna is 54.6 mm, its width is 2 mm, and the length of the insert is 51.6 mm. The flexible antenna-wristband is connected to the printed circuit board of the infocommunication device by soldering or using a mini-coaxial cable. The authors developed an experimental layout of a flexible antenna-wristband and studied its wave and directional properties. It has been established that in the frequency range 800–1300 MHz the voltage standing wave ratio coefficient of this antenna does not exceed 3.5. The flexible antenna-wristband has directional properties, which allows reducing the level of electromagnetic radiation in the direction of the human body.

Artificial intelligence is employed for solving complex scientific, technical, and practical problems. Such artificial intelligence techniques as neural networks, fuzzy systems, and genetic and evolutionary algorithms are widely used for communication systems management, optimization, and prediction. Artificial intelligence approach provides optimized results in a challenging task of call admission control, handover, routing, and traffic prediction in cellular networks. 5G mobile communications are designed as heterogeneous networks, whose important requirement is accommodating great numbers of users and the quality of service satisfaction. Call admission control plays a significant role in providing the desired quality of service. An effective call admission control algorithm is needed for optimizing the cellular network system. Many call admission control schemes have been proposed. The paper proposes a methodology for developing a genetic neurofuzzy controller for call admission in 5G networks. Performance of the proposed admission control is evaluated through computer simulation.

Purpose. Investigation of a moisture frequency transducer based on a moisture-sensitive capacitive element of a cylindrical structure with mesh electrodes for a system for measuring the amount and parameters of crude oil. Methodology. When constructing a moisture-sensitive element, an oscillatory method for measuring humidity was applied to achieve high sensitivity and accuracy while maintaining a low cost of the device. A moisture sensitive capacitive sensor based on a cylindrical structure with mesh electrodes was introduced into the measuring generator system based on a transistor structure with a negative differential resistance. Findings. Analytical expressions are obtained to describe the dielectric constant of an inhomogeneous mixture of water and oil. Using these equations, the capacitance of a moisture-sensitive sensor with mesh electrodes is calculated as a dependence of the moisture content of crude oil. It was determined that the capacitance of the moisture sensitive sensor increased from 20 to 44 pF when the mass moisture of crude oil changed from 0 to 30%. The sensitivity of the developed capacitive sensor is 0.8 pF/% when using a measuring device in the form of a crude oil pipeline with a diameter of 50 millimeters. Originality. A mathematical model has been developed for the primary transducer of the moisture content of crude oil based on a cylindrical capacitor structure with net-like electrodes, which allows determining the value of the capacitance of the primary transducer of the moisture content of crude oil. A self-oscillator device for controlling the moisture content of crude oil has been developed on the basis of the structure of bipolar and field-effect transistors with a cylindrical capacitor structure with mesh electrodes. Practical value. Circuitry solutions for a moisture transducer for crude oil have been developed. The results of experimental studies showed that for the selected version of the moisture converter circuit, the output signal frequency decreased in the range from 1.617 to 1.27 MHz with a change in the mass moisture content of the Turkmen mixture from 0 to 30%, respectively, and is close to a linear dependence. The wide frequency range of the output signal of the secondary converter with the frequency output of the measured information increases the accuracy of moisture measurement in crude oil by an order of magnitude.

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A problem of estimating the movement and orientation of a mobile robot is examined in this paper. The strapdown inertial navigation systems are often engaged to solve this common obstacle. The most important and critically sensitive component of such positioning approximation system is a gyroscope. Thus, we analyze here the random error components of the gyroscope, such as bias instability and random rate walk, as well as those that cause the presence of white and exponentially correlated (Markov) noise and perform an optimization of these parameters. The MEMS gyroscopes of InvenSense MPU-6050 type for each axis of the gyroscope with a sampling frequency of 70 Hz are investigated, as a result, Allan variance graphs and the values of bias instability coefficient and angle random walk for each axis are determined. It was found that in the output signals of the gyroscopes there is no Markov noise and random rate walk, and the X and Z axes are noisier than the Y axis. In the process of inertial measurement unit (IMU) calibration, the correction coefficients are calculated, which allow partial compensating the influence of destabilizing factors and determining the perpendicularity inaccuracy for sensitivity axes, and the conversion coefficients for each axis, which transform the sensor source codes into the measure unit and bias for each axis. The output signals of the calibrated gyroscope are noisy and offset from zero to all axes, so processing accelerometer and gyroscope data by the alpha-beta filter or Kalman filter is required to reduce noise influence.

The method of non-destructive control of the molecular structure of solid materials is improved, the distinguishing feature of which is a new sign of suitability for the peak values of the thermodynamic process in solid materials, which made it possible to increase the reliability of the non-destructive control. A statistical norm for deciding on the suitability of solid materials was introduced, which made it possible to organize statistical express control of solid materials under conditions of industrial production of electronic devices. In the practical plan, a structural scheme and an algorithm for measuring control of the peak values of the differential-thermal analysis of solid materials are proposed, on the basis of which a microprocessor based device for statistical express control is developed.