SIC Backed Slot Antenna with Exceptionally Low Cross-Polarization for Sub-6 GHz 5G Band

A low-profile, single-layered, single-fed slot antenna has been designed to maintain low cross-polarization across its entire operating bandwidth. This antenna design features a circular-shaped cavity resonator implemented using embedded vias in a circular fashion, so-called substrate-integrated cavity (SIC). A square-ring slot is incorporated on the top surface of the cavity. The antenna is fed using a probe feed which excites the design in dual mode, i.e., slot mode and inset patch mode. Due to the proximity of these dual resonances, the antenna operates over a relatively wider bandwidth than previously suggested designs with the claim of low cross-polarization. The suggested design confirms a co-pol to cross-polarization isolation of over 40 dB in both
$E$
and
$H$
planes. Overall experimental results demonstrate a good radiation performance, confirming up to 15-20dB improvement in cross-polarization level. The proposed design holds promise as a viable solution for the Sub-6 GHz 5G band.