Research and Development in the Field of Creating Materials, Technologies and Safety Equipment

Abstract

Technologies for the manufacture of microwave electromagnetic shields based on powdered carbon, foil and composite multilayer materials are presented. Technological methods for their manufacture and shielding properties are described, and the main mechanisms leading to increased shielding properties are considered depending on the manufacturing technology, composition and alternation of composite layers. It is shown that the values of the reflection coefficient of electromagnetic radiation in the frequency range 2–17 GHz for the shields considered reach a value of (–20) dB. Microwave absorbers with a reflection characteristic lower than (–10.0) dB (down to (–52.0) dB) in the frequency band 8.0–12.0 GHz are developed, and the electrophysical parameters, composition and concentration of components of the composite materials for such microwave absorbers are determined. The systems for active protection of speech information that use combined masking signals consisting of “white” noise and speech-like signals as masking signals, along with “white” noise are considered. Criteria have been developed for the approach to selecting speakers and audiences when assessing speech intelligibility to solve problems of protecting speech information and methods for experimental studies of speech intelligibility against a background of masking acoustic noise. Technologies for the formation of nanocomposites based on carbon nanotubes and nanoparticles of ferromagnetic materials are presented to increase the degree of coherence of the spin texture at macroscopic distances, increase the degree of security of electronic products to strong magnetic fields and noise immunity. It has been shown that at certain concentrations of ferromagnetic nanoparticles, micromagnetic parameters increase, ensuring high performance of active elements in magnetic fields. The role of carbon in this case turns out to be decisive. The presented results seem promising for use in the creation of anechoic chambers, partitions for separating indoor zones intended for the location of electronic devices, products for protecting humans from the effects of electromagnetic radiation in the microwave range, and the formation of combined masking signals in the form of “white” noise for devices protection of speech information, composite coatings to level out the effects of a constant magnetic field on electronic products.