Broadband array antennas using a self-complementary antenna array and dielectric slabs

In English It is well known that planar self-complementary structures have a constant
input impedance and hence they are good candidates for ultra-wideband antennas.
However, introduction of a ground plane breaks the symmetry and
destroys the broadband property. In this paper, it is shown that stacking of
dielectric slabs above the antenna elements can reduce the degrading eject of
the ground plane. The dielectric slabs act as filters adding loops in the center
of the Smith chart. The results are illustrated with infinite antenna arrays
with broadside bandwidths of 4.7:1 at -13dB and of 5.5:1 at -17dB for the
cases of two and three dielectric slabs, respectively.