  Periodic arrays of antidots, i.e. nanoscale perforations, in graphene enable
tight confinement of carriers and efficient transport barriers. Such barriers
evade the Klein tunneling mechanism by being of the mass rather than
electrostatic type. While all graphene antidot lattices (GALs) may support
directional barriers, we show, however, that a full transport gap exists only
for certain orientations of the GAL. Moreover, we assess the applicability of
gapped graphene and the Dirac continuum approach as simplified models of
various antidot structures showing that, in particular, the former is an
excellent approximation for transport in GALs supporting a bulk band gap.
Finally, the transport properties of a GAL based resonant tunneling diode is
analyzed indicating that such advanced graphene based devices may, indeed, be
realized using GAL structures.
