UWB dual‐polarised dipole array with dielectric and FSS superstrate and 65° scanning

The authors report the design of an ultra‐wideband (UWB), dual‐polarised, tightly coupled dipole array (TCDA) with an integrated balun for wide‐angle scanning. A dual‐pol dipole design enables massive bandwidth, large scanning volume, and high polarisation purity, concurrently. To achieve wide‐angle impedance matching without exciting surface waves, two types of superstrates are evaluated on a finite array: (i) dielectric superstrate and (ii) novel planar frequency‐selective surface (FSS). The latter architecture is capable of scanning 70° in E‐ plane and 65° in H‐ plane and shows, on average, 5° scanning improvement to the former. The impedance bandwidth is 5.25:1 (0.8–4.2 GHz) at the broadside (voltage standing wave ratio (VSWR)<2). The bandwidth reduces to 4.3:1 (0.9–3.9 GHz) when the maximum scanning angle or θ max increases to 65° for the H ‐plane and 70° for the E ‐plane (VSWR < 3.2). The proposed array is a great candidate for wide‐angle wideband scanning applications covering the entire L and S bands.