Graphite nano-platelet-based composites for microwave absorbing small enclosures

The use of novel nanocomposites, consisting in polymeric-based system filled with graphite-nanoplatelets (GNP), is proposed to increase the shielding performance and to reduce the Q of small enclosures excited by impinging plane waves in the gigahertz frequency range. Structure and electrical characteristics of the realized GNP-based composites are described. Absorbing performances of a planar infinite screen made with two layers panel backed on a metallic surface, illuminated by a TM and a TE polarized plane waves, are computed in reverberating conditions. The same absorbing nanostructure is considered to realize the walls of a small-dimensions cubic box with a slot aperture. The full-wave numerical simulations demonstrate that the use of the new material produces resonance damping of microwave electric field and a factor 10⁴ reduction of the Q of a full-metallic enclosure.