STUDY OF THE EFFICIENCY OF RESONANT ELECTROMAGNETIC SCREENS

Abstract

The possibilities of developing a single-layer protective coating with low coefficients of electromagnetic waves of ultra-high, ultra-high and extremely high frequencies are investigated. It is determined that the required reflection coefficients are achieved by matching the electrical and physical thicknesses of the protective material. The desired parameters are regulated by selecting a material with a certain dielectric constant. The use of magnetite (ε = 24) as a filler in the dielectric matrix (ε = 14) allows the use of the ratio to calculate the dielectric efficiency. The presence of magnetic properties in magnetite ( = 4.5) makes it possible to simultaneously shield electromagnetic fields of industrial frequency with shielding coefficients of 6–8. It has been established that for the electrical thickness of the material equal to one (first order of quarter-wave protection) at a frequency of 1 GHz, an acceptable reflection coefficient (-10 dB) is achieved in the frequency band from 0.9 to 1.1 GHz, at a frequency of 3 GHz – from 2.3 to 3.3 GHz, at a frequency of 6 GHz – from 5.3 to 6.6 GHz, at a frequency of 10 GHz – from 9 to 11 GHz. This makes it possible to take into account a certain range of operating frequencies of equipment of certain standards in practice. It should be borne in mind that when determining the effective permittivity of a composite material using known ratios, a large error is observed. Therefore, the maximum values should be used in the calculations, which will allow obtaining a certain margin of efficiency in determining the electrical thickness of the material.