  The electronic structure of a graphene superlattice composed by two periodic
regions with different Fermi velocity, energy gap and electrostatic potential
is investigated by using an effective Dirac-like Hamiltonian. It must be
expected that the change of the Fermi velocity in one region of the graphene
superlattice is equivalent to changing the width of this region keeping the
Fermi velocity unchanged, provided that the time taken to charge carriers cross
the region is the same. However, it is shown here that these two systems are
not equivalent. We found extra Dirac points induced by the periodic potential
and their location in the \textbf{k} space. It is shown that the Fermi velocity
modulation breaks the symmetry between the electron and hole minibands and that
it is possible to control the behavior of the extra Dirac points. The results
obtained here can be used in the fabrication of graphene-based electronic
devices.
