A mode-based supergain approach with closely coupled monopole pair

This paper focuses on a mode-based approach that can obtain the maximum gain from closely coupled antennas. Because of the small separation between the coupled dipole antennas, the antenna gain can potentially surpass the physical aperture limit and thus be called supergain. Traditional supergain antennas are actually superdirective only as the directivity can not be translated into real antenna gain because of severe impedance mismatching in those systems.