The use of multi-layered chiral structures as filters in the microwave
frequency range is studied in this paper. These chiral devices can re
place their dielectric counterparts when the synthesis of the latter h
as furnished values of refractive indices which are unavailable, and,
in addition, they are able to rotate the plane of polarization of the
transmitted wave by a given angle. These features are achieved due to
the extra degree of freedom provided by the chirality admittance. The
sensitivities of the two kinds of filters are calculated, analyzed and
compared. The dependence of the permittivity of the medium on the chi
rality admittance is taken into account in order to evaluate its influ
ence on the characteristics of the chiral filter and to compensate for
it. Finally an accurate model which considers lossy frequency depende
nt parameters, is used to design a wide stop-band filter. The chiral f
ilter is compared to a dielectric one: a large attenuation at the stop
-band, a steep response at the cutoff frequency and a wide stop-band,
are the three main advantages of the chiral filter over its dielectric
counterpart.