DIELECTRIC SUBSTRATES
Dielectrics are often used to provide structural support or
stabilizing the angular response of an FSS. The dielectric
constant becomes very sensitive to the substrate thickness.
Accordingly, the frequency resonant will be sensitive to the
substrate thickness. Figure 4 shows the frequency response of
the FSS for different values of epsilon, εr. It is observed that the
dielectric constant of the substrate exhibits a great influence. A
higher dielectric constant leads to a lower resonant frequency
and a narrower bandwidth. It is also seen that a better band
rejection performance can be achieved using a substrate of
higher dielectric constant.