Analytical expressions are obtained for the electron transport and bou
nd state properties of periodic quantum wires in the single-mode appro
ximation. These give both qualitative and quantitative understanding o
f the emergence of minibands in the low-energy region. The quantum-dot
superlattice discussed by J A Brum (1991 Phys. Rev. B 43 12 082) is t
aken as an example.