A differential-fed unidirectional antenna for ultra-wideband applications

Abstract

A novel differential-fed magneto-electric dipole antenna with unidirectional radiation pattern is proposed. Based on the differential feed scheme presented in [1], a new pair of differential feeds is developed to provide an ultra-wideband impedance matching. Instead of a planar reflector, a rectangular box-shaped reflector is utilized to reduce the fluctuation of the antenna gain. The proposed antenna achieves an impedance bandwidth (SWR ≤ 2) of 132% from 2.48 to 12.12 GHz and a gain varying between 7.16 and 14.1 dBi. Over the operating frequency range, radiation patterns with low cross polarization and low back radiation have mainbeams fixing broadside direction.