Кафедра електроніки, фізики та СМАРТ-систем
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Item type:Наукова стаття, DEVELOPMENT OF A MODIFIED METHOD OF NETWORK TRAFFIC FORMING(2023-03-31) Kozlovskiy, Valeriy; Yakymchuk, Natalia; Selepyna, Yosyp; Moroz, Serhii; Tkachuk, AnatoliiBased on the analysis of the statistical characteristics of heterogeneous network traffic of "Quadruple Play" mobile subscribers, it is shown that it cannot be represented by Poisson or Erlang distributions. It is shown that for such similar traffic, the rate of growth of the required buffer volume increases as the Hurst parameter increases. A method of adaptivetraffic formation using the control of the length of intervals of the intensity of the arrival of data packets has been developed. Congestion management is carried out by changing the frequency of the marker generator (GM) on the basis of the results of forecasting the required bandwidth of the system and the required buffer size. The shaper adapts to changes in the length and instantaneous intensity of packet input in real-time.Item type:Наукова стаття, MODEL OF THE FLAT FAIRING ANTENNA DIELECTRIC LAYER WITH AERODYNAMIC HEATING(2023-12-20) Kozlovskiy, Valerii; Kozlovskiy, Valeriy; Nimych, Oleksii; Klobukova, Lyudmila; Yakymchuk, NataliaTo protect the antenna systems of modern aircraft, radio-transparent dielectric fairings are widely used. At low flight speeds, when designing and evaluating the characteristics of the fairing-antenna, it is assumed that the dielectric constant is a constant value and does not depend on the aircraft's flight speed. As the flight speed increases, as a result of aerodynamic heating of the fairing, its dielectric permeability changes, which leads to errorsin the processing of received signals. Currently, to take into account the effect of dielectric coatings heating when designing antenna systems,the temperature of the fairing wall is averaged over its thickness. This method during maneuvering and at high flight speeds leads to large errorsin determining the characteristics of the fairing antenna since the nature of the temperature distribution along the thickness of the fairing wall is not taken into account. A new approach to the analysis of dielectric layers with their uneven heating along the thickness is proposed. The obtained results makeit possible to adjust the signal processing algorithms with analog and digital matrices, as a result of taking into account the emerging heat flows affecting the fairing of the aviation antenna, which leads to the improvement of the characteristics of the antenna systems.Item type:Наукова стаття, Synthesis of Bandpass Filter as a Four-Pole Based on a Non-Homogeneous Line(2024-07-29) Kozlovskiy, Valeriy; Kozlovskiy, Valerii; Boiko, Juliy; Balanyuk, Yuriy; Yakymchuk, NataliaThe article deals with the synthesis of band-pass filters (BPF) for the design of microwave filtering devices, by using non-homogeneous lines (NL) with the selection of the appropriate wave impedance W. For this purpose, equivalent NL substitution circuits were created in the region of resonant and anti-resonant frequencies, and four-pole matrices of the transmission line were determined, whose matrix of impedances and admittances does not have partial poles, and the transmission admittance and transmission impedance do not have zeros. BPF prototypes were synthesized with two parallel plumes based on a closed homogeneous line and one plume based on three NLs. A band-pass filter with an extended blocking band was implemented, and its amplitude-frequency characteristics were obtained. The use of NLs as resonators allows the choice of wave impedance to increase the blocking band of the BPF compared to the BPF on resonators based on homogeneous lines.