DeIn recent years, there
have been several
new concepts applied
to distributed microwave
circuits. One such technique
is defected ground
structure or DGS, where
the ground plane metal of
a microstrip (or stripline, or coplanar waveguide)
circuit is intentionally modified to
enhance performance.
The name for this technique simply means
that a “defect” has been placed in the ground
plane, which is typically considered to be an
approximation of an infinite, perfectly-conducting
current sink. Of course, a ground
plane at microwave frequencies is far removed
from the idealized behavior of perfect ground.
Although the additional perturbations of DGS
alter the uniformity of the ground plane, they
do not render it defective.fected Ground Structures