Experimental researches of the characteristics of antennas in the presence of electromagnetic screens

2021 ◽  
Author(s):  
A.V. Shlyahov
Keyword(s):  
Electromagnetic Radiation ◽  
Electromagnetic Compatibility ◽  
Confined Space ◽  
Electromagnetic Environment ◽  
Innovative Technologies ◽  
Limited Application ◽  
Interference Frequency ◽  
Spaced Antennas ◽  
Experimental Researches ◽  
Antenna Systems

When placing various antenna systems in a confined space, one has to deal with a complex electromagnetic environment and insufficient isolation between the antennas. And, although the methods of ensuring electromagnetic compatibility of such groups of radio electronic means are well known, taking into account the peculiarities of the objects under consideration, they have very limited application. The use of innovative technologies developing in recent years, including the use of screens made of metamaterials, makes it possible to significantly expand the "limits of applicability" of these methods. As the studies have shown, the screen made of metamaterial has special characteristics in comparison with traditional screens, namely: at the operating frequency of the antenna, the screen is practically permeable to electromagnetic radiation, and at the interference frequency it becomes low-transparent and works as a reflector. The results can be used to improve isolation between closely spaced antennas, such as at the tops of towers or masts.

Gradient structures of Ni – Zn ferrites for electromagnetic radiation protection devices

2021 ◽  
Vol 5 ◽  
pp. 39-46
Author(s):  
V. V. Karanskij ◽  
◽  
S. V. Smirnov ◽  
A. S. Klimov ◽  
E. V. Savruk ◽  
...  
Keyword(s):  
Electron Beam ◽  
Electromagnetic Radiation ◽  
Radiation Protection ◽  
Electromagnetic Compatibility ◽  
Protective Coatings ◽  
Frequency Range ◽  
Near Surface ◽  
Zn Ferrite ◽  
Absorbing Materials ◽  
Plasma Electronic

Increasing the reliability requirements for electromagnetic compatibility of electronic equipment requires the creation of protective coatings that absorb electromagnetic radiation or the development of new radio-absorbing materials. In the frequency range up to 1 GHz, radio-absorbing materials based on Ni – Zn ferrites are of the greatest interest. The absorption of electromagnetic radiation by ferrites occurs due to resonant phenomena at the level of domains and atoms. Improving the performance of ferrites is possible by modifying their surface properties. In this paper, gradient structures for electromagnetic radiation protection products are obtained by treating the surface of Ni – Zn ferrite samples with a low-energy electron beam. To generate the electron beam, a unique development was used — a forevacuum plasma electronic source that allows forming and transporting a beam with a power density of up to 105 W/cm2 under conditions of high pressure and high gas release. As a result of processing, gradient structures were found on the surface of ferrites. A theoretical analysis and experimental study of the obtained structures “non – magnetic conductor – ferrite”, characterized by an increased attenuation coefficient and a reduced reflection coefficient of electromagnetic radiation in the frequency range from 0.5 to 2.5 GHz. The possibility of obtaining near-surface layers depleted in zinc with increased electrical conductivity and reduced magnetic permeability is shown.

ASSESSMENT OF THE ELECTROMAGNETIC ENVIRONMENT AND RADIO MONITORING OF SIGNAL PROPAGATION AND RECEPTION CONDITIONS

2020 ◽  
Author(s):  
С.В. КИЗИМА ◽  
Е.Г. РУДЕНКОВА
Keyword(s):  
Frequency Spectrum ◽  
Electromagnetic Compatibility ◽  
Measurement Data ◽  
Signal Propagation ◽  
Radio Sources ◽  
Electromagnetic Environment ◽  
Radio Monitoring ◽  
Radio Frequency Spectrum ◽  
Radio Signals ◽  
Problematic Situations

Рассматривается технология комплексного радиомониторинга излучений в заданной географической точке. Полученные результаты сопоставляются с разрешенными уровнями излучений. Технология направлена на решение задач оценки условий распространения и приема радиосигналов, планирования использования радиочастотного спектра (РЧС), выявления помех и других проблемных ситуаций, связанных с обеспечением электромагнитной совместимости ( ЭМС) действующих и перспективных радиосредств. The article describes the technology of complex radio monitoring of emissions from multiple radio sources. The measurement data are compared with the permitted emission levels. The application of the technology helps to assess the conditions for the propagation and reception of radio signals, planning the use of the radio frequency spectrum, identifying interference and other problematic situations related to electromagnetic compatibility of existing and promising radio facilities.

scholarly journals METHODS FOR ASSESSMENT AND FORECASTING OF ELECTROMAGNETIC RADIATION LEVELS IN URBAN ENVIRONMENTS

2021 ◽  
Vol 11 (1) ◽  
pp. 24-27
Author(s):  
Denys Bakhtiiarov ◽  
Oleksandr Lavrynenko ◽  
Nataliia Lishchynovska ◽  
Ivan Basiuk ◽  
Tetiana Prykhodko
Keyword(s):  
Electromagnetic Radiation ◽  
Radio Channel ◽  
Technical Information ◽  
Information Leakage ◽  
Urban Environments ◽  
Radio Interference ◽  
Structural Diagram ◽  
Electromagnetic Environment ◽  
Acoustic Information

Methods for synthesis a structural diagram of the processes for detecting and locating technical information leakage channels are analysed. Software for defining a controlled room zone was also presented. A proprietary approach to search the electromagnetic environment under radio interference has been developed to detect devices for unauthorized control of acoustic information using microphones and transmission of this information using a radio channel.

scholarly journals Electromagnetic radiation shielding composite coatings based on powdered alumina and ironoxide

Doklady BGUIR ◽  
2021 ◽  
Vol 19 (3) ◽  
pp. 104-109
Author(s):  
D. I. Penialosa Ovalies ◽  
O. V. Boiprav ◽  
M. V. Tumilovich ◽  
L. M. Lynkou
Keyword(s):  
Iron Oxide ◽  
Electromagnetic Radiation ◽  
Electromagnetic Compatibility ◽  
Composite Coatings ◽  
Radiation Shielding ◽  
Frequency Range ◽  
Reflection And Transmission ◽  
Powdered Iron ◽  
Transmission Coefficients ◽  
Experimental Substantiation

The  article  presents  the  results  of  experimental  substantiation  of  the  method  for  improving the shielding  properties  of  composite  coatings  based  on  powdered  alumina  (electrocorundum,  alum  earth), which  consists  in  modifying  the  composition  of  such  coatings  by adding  to  it  powdered  iron  oxide. This experimental substantiation consisted in the development of the technique for obtaining composite coatings based on powdered alumina and iron oxide, the manufacture of the experimental samplesusing the developed technique,  measurements  of  electromagnetic  radiation  reflection and  transmission  coefficients  values in the frequency range 0.7…17.0 GHz of the manufactured samples; implementation of the comparative analysis of the measured values with the similar values typical for the composite coatings filled with powdered alumina oxides, and composite coatings with the fillers such as powdered iron oxide. The obtained results revealed that by  adding  powdered  iron  oxide  to  the  composite  coatings  based  on powdered  alumina  oxides,  it  is  possible to reduce by 1.0…8.0 dB their electromagnetic radiation transmission coefficient values in the frequency range 0.7…17.0 GHz. In addition, we found that the implementation of the proposed method allows one to decrease by  2.0…20.0  dB  the  electromagnetic  radiation  reflection  coefficient  values  in  the  specified  frequency  range of the considered composite coatings, if such are applied to metal substrates. We propose to use the composite coatings, obtained on the base of the substantiated method, in order to ensure the electromagnetic compatibility of radio-electronic equipment.

scholarly journals Detecting Electromagnetic Geographical Environment Changes Based on the Frequency-Intensity Curve

2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Yi Huang ◽  
Mengyi Wang ◽  
Qianqian Qiu ◽  
Lizhi Miao ◽  
Haiping Zhang ◽  
...  
Keyword(s):  
Electromagnetic Radiation ◽  
Communication Systems ◽  
Human Life ◽  
Radiation Condition ◽  
Electromagnetic Environment ◽  
Intensity Curve ◽  
Monitoring Method ◽  
Geographic Environment ◽  
Spatial Positioning ◽  
Frequency Intensity

Electromagnetic geographic environment is closely related to human life. With continuous popularization of public infrastructures and daily electronic instruments, such as electric power communication systems and household appliances, electromagnetic radiation sources have increased sharply in the geographic environment, which leads to increasingly serious electromagnetic radiation pollution. Thus, it is significant to monitor, evaluate, and analyze the electromagnetic radiation condition and explore its changing law in the environment. However, the traditional monitoring method can only detect anomalies within certain frequencies in the fixed stations. To fill this gap, this research first develops a vehicle-mounted electromagnetic environment monitoring system to collect both spatial positioning data and electromagnetic data of the whole frequency range. The acquired data are then used to construct the location-based frequency-intensity curve to reflect the variation of electromagnetic radiation at different frequency ranges. On this basis, a curve similarity measurement method is introduced to analyze the similarity of different curves, which is effective to diagnose time-varying sources from both global and local perspectives. This research provides a real-time mobile monitoring method, which is significant to know the dynamic variation of local electromagnetic environment and promotes subsequent comprehensive geographic analyses.

scholarly journals Solving the Problem of Optimizing the Electromagnetic Environment in Radio Access Networks Using Neural Networks

2021 ◽  
Vol 7 (3) ◽  
pp. 25-37
Author(s):  
O. Kazmin ◽  
O. Simonina
Keyword(s):  
Neural Networks ◽  
Fuzzy Logic ◽  
Control System ◽  
Power Management ◽  
Management System ◽  
Electromagnetic Compatibility ◽  
Access Networks ◽  
Electromagnetic Environment ◽  
Radio Access ◽  
Power Management System

The article proposes an algorithm for controlling the electromagnetic environment in a Wi-Fi WLAN using fuzzy logic methods. A power management system for access points has been developed, deployed using the Wi-Fi segment based on existing equipment. The use of an electromagnetic compatibility control system in high-density Wi-Fi networks can significantly improve the bandwidth of the wireless segment.

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