Broadband Electromagnetic Absorbing Structures Made of Graphene/Glass-Fiber/Epoxy Composite

Radar-absorbing structures (RASs) with improved mechanical properties and subwavelength thickness are of particular interest for aerospace applications and electromagnetic (EM) interference control. This article proposes a new RAS, made of a graphene-filled lossy laminate (LL) with impedance adapter, having a total thickness less than 4 mm and a normalized absorption bandwidth of 84% in the frequency range 6-18 GHz. The RAS is designed by applying an innovative simulation approach of the graphene-filled LL, which is based on the multiscale Maxwell Garnett model and the effective medium theory. Experimental tests are performed in order to validate the developed model and to assess the absorption properties of the produced RAS, having a minimum reflection of -30 dB and an absorption bandwidth at -10 dB of 10 GHz, with a central frequency of 12 GHz and a graphene nanoplatelets concentration less than 5 g/m
²
.