Performance of Tri-Band Multi-Polarized Array Antenna for 5G Mobile Base Station Adopting Polarization and Directivity Control

In this paper, the performance of tri-band multi-polarized adaptive array antenna for 5G mobile base station is introduced adopting the polarization and directivity control. First, the design of multi-band circularly polarized antenna element at 28/38/48 GHz is presented. The measured results show that the designed antenna element has a reflection coefficient of less than -20 dB in the assigned frequency bands of 28/38/48 GHz with a realized antenna gain of 7.82 dB, 8.39 dB, and 7.73 dB, respectively. Based on the designed antenna element, a 32-element are distributed in an octagonal prism configuration is presented as possible candidates for the future 5G mmWave cellular networks. The antenna array performance is studied in terms of gain, radiation efficiency, return loss, and axial ratio for different scenarios, in addition, the metrics of total scan pattern and coverage efficiency are investigated. To optimize the antenna parameters and synthesizing multi-beam patterns, a modified version of hybrid gravitational search algorithm and particle swarm optimization algorithm is introduced. This enhancement has improved the global search ability and accelerates the convergence capability. The proposed array antenna achieved good S-11 < -20 dB with high isolation between the array elements. Besides, an acceptable realized gain of 16.85 dB on average with a radiation efficiency of more than 82 % is obtained in the entire operation bands.