Wideband monopole antenna tightly aligned to the ground plate
The authors propose a wideband monopole antenna that is tightly aligned to one edge of its ground plate. Wideband impedance matching with fractional bandwidth of ∼93% is attained by varying stepwise the lateral alignment of the monopole and the ground plate so that the feed side of monopole partially overlaps the ground plate. The tight alignment and overlap concentrates a part of the electric field such as a travelling wave. The step structure rotates the electric field so that the concentrated electric field in the feed side orients roughly the same direction with the electric field in the tip side which is converted into radiation. The basic antenna characteristics are examined by simulation, and verified in experiments.