  A sheet of graphene under magnetic bias attains anisotropic surface
conductivity, opening the door for realizing compact devices such as Faraday
rotators, isolators and circulators. In this paper, an accurate and analytical
method is proposed for a periodic array of graphene ribbons under magnetic
bias. The method is based on integral equations governing the induced surface
currents on the coplanar array of graphene ribbons. For subwavelength size
ribbons subjected to normally incident plane waves, the current distribution is
derived leading to analytical expressions for the reflection/transmission
coefficients. The results obtained are in excellent agreement with full-wave
simulations and predict resonant spectral effects that cannot be accounted for
by existing semi-analytical methods. Finally, we extract an analytical, closed
form solution for the Faraday rotation of magnetically-biased graphene ribbons.
In contrast to previous studies, this paper presents a fast, precise and
reliable technique for analyzing magnetically-biased array of graphene ribbons,
which are one of the most popular graphene-based structures.
