  We investigate the conductance spectra of a normal/superconductor graphene
junction using the extended Blonder-Tinkham-Klapwijk formalism, considering
pairing potentials that are both conventional (isotropic s-wave) and
unconventional (anisotropic d-wave). In particular, we study the full crossover
from normal to specular Andreev reflection without restricting ourselves to
special limits and approximations, thus expanding results obtained in previous
work. In addition, we investigate in detail how the conductance spectra are
affected if it is possible to induce an unconventional pairing symmetry in
graphene, for instance a d-wave order parameter. We also discuss the recently
reported conductance-oscillations that take place in normal/superconductor
graphene junctions, providing both analytical and numerical results.
