A compact design of orthogonally dual-polarized antenna for ultra-wideband , imaging, and radar applications

Abstract

In this study, a new design of dual-polarized ultra-wideband (UWB) antenna is proposed. The antenna design contains a circularring slot radiator fed by two independently semi-arc-shaped microstrip feeding lines which can exhibit polarization diversity characteristic. A low-cost FR-4 dielectric (ε= 4.4, δ= 0.02) is used as the substrate. The characteristics of the dual-polarized UWB antenna are examined using both simulations and measurements and good results are achieved. An impedance bandwidth (S11 ≤ -10 dB) of 2.5-10.2 GHz with 121% fractional bandwidth (FBW) is achieved for the design. However, for S11 ≤ -6 dB, this value is more than 130% (2.2-11 GHz). The proposed UWB antenna offers good isolation, dual-polarized function, and sufficient efficiency which make it suitable for different applications such as radar and microwave imaging.