Dual-band switched-beam antenna array for MIMO systems

This work reports the development of a dual-band switched-beam antenna array for multiple-input multiple-output (MIMO) fifth-generation systems, operating in millimetre waves. The proposed antenna array consists of applying four slotted-waveguide antenna arrays (SWAAs), rotated by 30 degrees, as the final array element. The SWAA elements were designed to simultaneously operate in the 28 and 38 GHz bands, by using two groups of slots with different electrical lengths on the opposite faces of the waveguide. The measured array fractional bandwidth was similar to 25.6 and 10% at 28 and 38 GHz, respectively. Its applicability for MIMO systems was evaluated as a function of mutual coupling, active reflection coefficient, total active reflection coefficient and envelope correlation coefficient. Experimental results demonstrate low mutual coupling as low as -36 dB within the 28 and 38 GHz frequency bands.