  Using Chebyshev polynomials, we study the electronic transport properties of
massless Dirac fermions in symmetrical graphene superlattice composed of three
regions. Matching wavefunctions and using transfer matrix method, we explicitly
determine transmission probability as well as the conductance and Fano factor.
At vertical Dirac points, we numerically find that the transmission probability
shows transmission gaps, conductance has minimums and Fano factor has maximums.
