Improvement of Bandwidth Characteristics of Low-Profile Superdirective Antenna Composed of Asymmetric Dipole Element Backed by Planar Reflector

Abstract

A bandwidth of the superdirective antenna composed of an asymmetric dipole element backed by a planar reflector which has been proposed by the authors, is enhanced by incorporating both a self-complementary structure and a T-type monopole element into the original antenna. It is shown that a 6% bandwidth and a 4.8 dBi gain were obtained even though the thickness decreases to 0.02 wavelength at the center frequency. It is also shown that the developed antenna structure maintains a unidirectional property which is benefit for many IoT applications.