  The semi-classical conductance of a two-dimensional electron gas is
calculated in the presence of a one-dimensional modulated magnetic field with
zero average. In the limit of small magnetic field amplitudes (B) the
contribution of the magnetic modulation to the magnetoresistance increases as
$B^{3/2}$ in the diffusive limit, while the increase is linear in $B$ in the
ballistic regime. Temperature does not influence the power law behavior but it
decreases the prefactor of this functional behavior.
