A multiple-input multiple-output (MIMO) antenna with a defective ground surface (DGS) is proposed for next-generation millimeter-wave communication. The designed antenna consists of a pair of mushroom shape radiating units with two square ring-loaded defected common ground plane. The antenna is printed on duroid-5880 high-frequency laminates (loss tangent 0.0009, relative permittivity 2.2). Significant bandwidth ranges from 31.6 GHz to 48.8 GHz (impedance bandwidth of 43.17%) is obtained during the investigation of the antenna. The introduced MIMO antenna exhibits a low mutual coupling (|