DEFECTED GROUND STRUCTURE
DGS is an etched periodic or non-periodic cascaded configuration
defect in ground of a planar transmission line (e.g., microstrip, coplanar
and conductor backed coplanar wave guide) which disturbs the shield
current distribution in the ground plane cause of the defect in the
ground. This disturbance will change characteristics of a transmission
line such as line capacitance and inductance. In a word, any defect
etched in the ground plane of the microstrip can give rise to increasing
effective capacitance and inductance.
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