Disclosed is a wideband antenna with a lowered standing wave ratio. The
wideband antenna interposes a substance whose conductivity is about 0.1 through
10.0 as an interposition between a conductive plate and a radiation conductor;
and thereby, the antenna reduces reflections of signals, and achieves a wider bandwidth
as well as a sufficient gain with a lowered standing wave ratio. Also, the invention
realizes a thin-type wideband antenna with a wider bandwidth and a sufficient gain,
by interposing a magnetic substance whose relative permeability is more than 1
through about 8 as the interposition between the conductive plate and the radiation conductor.
