Scattering by a finite periodic potential

The problem of scattering in one dimension by a potential which consists of N identical cells is solved in a transparent manner. The N‐cell transmission and reflection amplitudes are expressed in terms of the single‐cell amplitudes and the Bloch phase. As examples the results are applied to a row of delta‐function potentials, and to a row of square wells, and it is shown that these expressions provide an immediate understanding of the results of detailed calculations.