  In this work, we investigated a simple structured graphene terahertz (THz)
metasurface (MSF) with perfect absorption, wideband, polarization insensitive,
oblique incidence insensitive and frequency reconfiguration. The graphene MSF
structure is composed of a two-dimensional periodic array of graphene
meta-atoms deposited on the silicon substrate terminated by a metal ground
plane. The performance of the proposed MSF is numerically analyzed. An
equivalent circuit model of the structure and its closed-form solution is
introduced. The graphene MSF thin structure at 2.5 THz provides 100% of
absorption with wide bandwidth, zero reflection and zero transmission at normal
incidence in both transverse electric (TE) and transverse magnetic (TM)
polarization. Under oblique incidence, the absorption is maintained at higher
than 95%. Moreover, the graphene MSF structure has the advantage of frequency
reconfiguration. The excellent absorption performance is maintained at all
reconfigurable frequencies upon reconfiguration. The results reveal the
effectiveness of the THz MSF with graphene meta-atoms, which can be promising
for THz wireless environment.
