Multilayer Microwave Absorbers with an Ordered Structured Layer Based on Powdered Activated Charcoal Containing Magnetic Particles

Abstract

The technique for manufacturing four-layer microwave absorbers with an ordered structured layer is presented. This technology involves heat pressing a structure comprising two fragments of synthetic non-woven fibrous material (the first and third layers). Between these layers, elements formed from powdered activated charcoal impregnated with a mixture of isopropyl alcohol and finely dispersed magnetic material (the second layer) are orderly distributed. Additionally, a fragment of an aluminum-containing foiled polymer film (the fourth layer) is fixed onto the surface of the third layer. It was found that the effective absorption bandwidth of the absorbers manufactured using the presented technique is 13.2 GHz, which exceeds the bandwidth of comparable absorbers by 4.7–11.2 GHz. The electromagnetic radiation absorption coefficient values of these absorbers range from 0.5 relative units to 0.92 relative units.