Dual-Fed DRA Subarrays Featuring Versatile Polarization Reconfigurability With High Port Isolation and Suppressed Cross-Polar Radiations

Abstract

near square Dielectric Resonator Antenna (DRA) geometry with dual-aperture feeding has been explored. This aims in achieving a number of attractive features from a standalone unit as well as a 4-element subarray. Unlike the earlier designs, it demonstrates four reconfigurable polarization states which are realized by conceiving a new near square shape of the DRA along with a novel feeding concept, proposed for the first time. They enable the subarray to significantly enhance the cross-polar discrimination (XPD). The design principles for dual-linear and dual-circular polarizations have been demonstrated and experimentally verified using a set of S-band prototypes. A dedicated digital phase network cum controller incorporating active switches has also been fabricated for practical examinations. A standalone prototype exhibits over 24.59% 10-dB return loss bandwidth at both ports with more than 40 dB inter-port isolation. It promises about 5.9 dBi/dBic consistent peak gain for all polarization states with more than 20 dB XPD. The subarray prototype reveals comparable 10-dB return loss bandwidths with more than 30 dB port-isolation and 25 dB XPD. The peak gain appears consistently around 11 dBi/dBic for all polarization states.