  The problem of one-dimensional quantum wire along which a moving particle
interacts with a linear array of N delta-function potentials is studied. Using
a quantum waveguide approach, the transfer matrix is calculated to obtain the
transmission probability of the particle. Results for arbitrary N and for
specific regular arrays are presented. Some particular symmetries and
invariances of the delta-function potential array for the N = 2 case are
analyzed in detail. It is shown that perfect transmission can take place in a
variety of situations.
