Wideband and Compact Dual-Polarized Array Antenna on Square Waveguide for 5G Applications

This paper presents a wideband and compact dual-polarized array antenna for millimeter-wave 5G applications. The antenna is designed based on a 16-way corporate feed network on square waveguide technology to support two orthogonal modes for operation over a wide bandwidth of 37 GHz to 42 GHz. To keep the antenna's size compact, a <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$4.4 mm \times 4.4 mm$</tex> square waveguide is used for the design with cut-off frequency at 34 GHz. Therefore, to cover lower band of the desired operating bandwidth of 37 GHz to 42 GHz for both polarizations, vertical and horizontal pairs of irises are employed in the feed network. In the presented design, element to element spacing is 5 mm equal to <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$0.65 \lambda$</tex> (at 39.5 GHz) which makes the structure compact and a good candidate for beam-steering applications. Based on the simulation results, the designed antenna shows a return loss of less than almost −10 dB, stable realized gain of better than 18.8 dBi, and side lobe level of less than −13 dB for both vertical and horizontal polarizations. The designed prototype has been fabricated by 3D printing machine and the measurement results prove the accuracy of the achieved simulation results.