Design of Dual-band Dual-polarized MIMO Antenna for mm-wave 5G Base Stations with Octagonal Prism Structure

This paper presents design of 5G multiple input multiple output (MIMO) antenna for 5th generation (5G) base stations. The proposed antenna is dual band and it operates at millimeter-wave (mm-wave) frequencies 28 GHz and 38 GHz. It is also dual-polarized and it can switch between vertical and horizontal polarizations. The sub-array is formed of four gap-coupled microstrip slotted dual-band patch antennas with corporate microstrip feed network. The sub-array exhibits realized gain greater than 12 dBi at 28 GHz and 38 GHz and 10-dB bandwidth of around 1 GHz at 28 GHz and 38 GHz. The antenna sub-arrays are arranged on the sides of an octagonal prism to synthesize multi-beam radiation patterns with twelve sub-arrays distributed on each side of the prism. The proposed antenna has the capability of steering the pattern to particular directions by switching between antenna sub-arrays placed on either side of the prism. The proposed antenna is a good candidate for 5G base stations as it achieves polarization and pattern diversity and fulfills 5G system requirements in terms of high gain, adequate bandwidth, MIMO configuration and fixed beam-switching capability.