A Slot-Loaded Dual-Band MIMO Antenna with DGS for 5G mm-Wave Band Applications

A dual-band slot-coupled MIMO antenna has been designed for base station applications. The radiating structure consists of eight antennas placed on top of Rogers RT/Duroid substrate of permittivity 2.2 and thickness 1.6 mm with four antennas operating under transmit mode and four operating under receive mode. By making U shaped slot on the antenna structure resulted in dual resonant frequencies corresponding to 28 GHz and 36 GHz. The novelty of the proposed work lies in using a rectangular annular ring loaded with dumbbell-shaped defected ground structure (DGS) etched on the ground plane of the antenna to increase the bandwidth and reduce the coupling. Further, square-shaped planar electromagnetic bandgap (EBG) cells have been added to improve the gain of the antenna array. The coupling between the antenna elements of the array decreased from −10 dB to −15 dB and the response remained flat in the operating bandwidth of the antenna with the introduction of DGS. The structure resulted in an envelope correlation coefficient (ECC) of 0.003 and a diversity gain of 10dB in the operating band of the antenna structure.