A resonant antenna is one that operates by means of
a standing wave. A resonant antenna is often usefully thought
of as being a transmission line with the two conductors
separated.
A resonant antenna is usually connected to the antenna feeder,
with other ends of the antenna left unconnected.
A resonant antenna
is often narrowband, because the optimum working frequency of the
antenna depends on its dimensions.
Types of resonant antenna include the
monopole antenna and the dipole antenna.