Design of a Dual-polarized SIW Cavity-backed Self-Quadruplexing antenna for mmWave 5G Applications

Design of a dual-polarized substrate integrated waveguide (SIW) based cavity-backed self-quadruplexing antenna is presented in this paper for fifth-generation (5G) millimetre-wave (mmWave) applications. In the proposed antenna, the metal plate at the top of the square SIW cavity is perturbed into eight rectangular patches of four different lengths each. The patches are designed/arranged to radiate into vertical and horizontal polarizations at 24.25, 26.5, 27.5, and 29.5 GHz simultaneously. With the proper placement of patches, isolation of more than 20 dB is obtained among the ports. The proposed antenna exhibits peak gains of 4.45, 4.28, 3.7, and 3.84 dBi at the above resonant frequencies. It has unidirectional radiation patterns with cross-polarization and front-to-back ratios better than 18 dB and 10 dB in all the bands. Moreover, the individual frequency-tuning capability of the antenna shows that it can be tuned to any of the mmWave 5G NR bands: n257, n258, n261 recommended by the U.S. Federal Communications Commission for 5G applications.