where In cm is the nth harmonic component of the CM current
without any filter and In cmf is the nth harmonic component
of the CM current the active filter without or with feed-forward
action. It should be observed that, for a given layout, α in (5)
gives a measure of the reduction of the energy content associated
to CM EMI. From Table VII, it is possible to observe
that the introduction of the active filter scheme without the additional
feed-forward current action leads to a reduction of the
EMI of about 13%, whereas the introduction of the active filter
scheme with the additional feed-forward current action leads to
a reduction of about 65%.