Design of a Wideband Wide-Angle Scanning Connected Slot Array Antenna for 5G-NR FR1 Band

This article presents a planar dual-polarised wideband, and wide-scanning array antenna based on the connected slot array principle. Its polarization diversity and scanning angle are further improved by employing coupling capacitance between neighboring elements and feeding the antenna slots using line-fed stubs. This combination lowers active input impedance, avoiding the usage of complex balun, while achieving wideband operation using a simple feeding structure. L-shaped metallic walls are employed to shift the common-mode resonances out of the antenna’s operating frequency while improving cost efficiency. A simple and low-cost metasurface is integrated as a wide-angle impedance matching (WAIM) layer on the array to enhance its beam scanning performance. Measurement of a 8 × 8 fabricated prototype of the array indicated its wideband behaviour at broadside (from 1.6 to 4.2 GHz), with wide-angle scanning capability of up to ±65° (from 1.65 to 4.1 GHz) in the E-and D-planes, and ±55° (from 1.7 to 4.1 GHz) in the H-plane, maintaining an active VSWR < 3. These results agreed well with simulations, offering a cost-efficient, wide-bandwidth, wide scanning range solution for antenna arrays for 5G base stations.