3D-printed stepped structure based on graphene-FeSiAl composites for broadband and wide-angle electromagnetic wave absorption

Abstract

The design and preparation of absorbers with ultra-wide bandwidth and wide-angle absorption characteristics are crucial technologies for addressing electromagnetic (EM) pollution. In this paper, a stepped structure absorber was fabricated of graphene (GR)-FeSiAl/polylactic acid (PLA) composite by 3D printing technology. The absorber contains four layers, the bottom layer being a slab with periodic square holes, and the upper layer is a periodic distribution of three cubes with equal thickness and gradient changes in side length. It is shown that the stepped structure achieves a minimum reflection loss (RLmin) of −36.01 dB, with an effective absorption bandwidth (EAB, corresponding to the bandwidth of RL < −10 dB) of 12.75 GHz. These results were obtained when the unit cell had a side length of 22.5 mm, the slab thickness was 1.5 mm, and the cube had a thickness and edge length difference of 2.5 mm and 4.0 mm, respectively. Furthermore, the value of EAB is greater than 10 GHz for both transverse electric (TE) polarization and transverse magnetic (TM) polarization when the incident angle changes from 0° to 50°. The broadband and efficient EM wave (EMW) absorption characteristics of this absorber can be attributed to integration of excellent impedance matching and the multi-scale loss mechanisms.