  We start from a one-dimensional periodic multilayered stack in order to
define a frequency power expansion of effective permittivity, permeability and
bianisotropic parameters. It is shown from the first order that a simple
dielectric multilayer can display a magnetoelectric coupling effect and, from
the second order, that artificial magnetism can be obtained with arbitrary low
contrast. However, this frequency power expansion is found to diverge at the
first band gap edge. Thus, an alternative set of effective parameters, made of
the propagation index and the surface impedance, is proposed. It is established
that these effective parameters, as functions of the complex frequency, possess
all the analytic properties required by the causality principle and passivity.
Finally, we provide arguments to extend these results to the three-dimensional
and frequency-dispersive case.
