Design and analysis of a wideband microwave absorber based on graphene-assisted metamaterial

Microwave absorption materials or structures show great application prospects in the design of 5 G systems. A graphene-assisted wideband metamaterial microwave absorber with polarization insensitivity and wide incidence angle is proposed based on the round-with-square-hole (RSH) shaped monolayer graphene structure in this paper. The calculation results of the device over an ultra-wideband (16-100 GHz) yields good absorption above 90% when the chemical potential of graphene is 0.1 eV. The fractional bandwidth is 145% for both transverse electric and transverse magnetic polarizations with normal incidence. The influences of the geometry structure parameters and graphene chemical potential on absorption characteristics have been investigated. The structure exhibits polarization independent and wide incidence angle properties since the geometrical symmetry structure. In addition, the structure provides excellent performance when the whole thickness of the device is less than 1 mm. Mechanism of the wideband operation is deciphered based on the normalized relative impedance, surface current and electric field distributions. The novel microwave absorber demonstrates great potential in various fields of electromagnetic stealth, electromagnetic interference shielding, 5 G systems, and so on.