Designing finishing materials with a gradient of electrophysical properties

Abstract

Тhe article discusses the basics of development and production of materials for shielding electromagnetic fields in a wide range of frequencies. The purpose of these materials is to cover large surface areas. The basic requirements for these types of materials have been established. The main ones are: the front surface must have electrophysical properties (dielectric and magnetic permeability) to ensure the lowest possible reflection coefficient of electromagnetic waves. At the same time, it is mandatory to simultaneously ensure the characteristics of strength, fire resistance, non-toxicity, etc. The content of radio-absorbing particles and effective dielectric (magnetic) permeability in the interlayer of the layered structure in the direction of growth of the substrate should ensure broadband and efficiency of the material. The dispersion dependence should ensure uniform absorption of electromagnetic energy and its passage from the input surface to the substrate in a given frequency range. Based on the maximum and minimum wavelengths of the shielding field, permeability and thickness of individual layers, calculations of the required thickness of the gradient material for a given reflection coefficient are given. Thanks to heat treatment of the surface of the material in the manufacturing process, the possibility of manufacturing monolithic metal-polymer screens with surface layers of low dielectric permeability is shown. The possibility of creating monolithic metal-polymer screens from ferromagnetic finely dispersed substances with an adjustable gradient in the direction from the front surface to the bottom is demonstrated, and a technical solution is given. This material can be used to control the ratio of shielding factors for high-frequency electromagnetic fields, ultra-low-frequency electric and magnetic fields, as well as concomitant shielding from natural magnetic fields.