Abstract: Compact 24-port and 36-port multiple-input-multiple-output (MIMO) antenna designs and methods of construction based on a cube-like structure are provided. The antennas can be implemented with slot antennas distributed on the edges and faces of cubes. According to various embodiments of the disclosed subject matter, both spatial and polarization diversity can be achieved and average mutual couplings among the ports better than ?20 dB can be achieved providing good channel capacity in MIMO applications. The disclosed details enable various refinements and modifications according to antenna and system design considerations.