Slot MIMO Cube

A 12-port slot hollow cube is presented as a compact MIMO antenna. At the second resonance (Z-/λ=0.7) the 10 dB 50 Ω impedance relative bandwidth for each element is 30%. The mutual coupling is low but finite. To investigate the nature of the coupling, the cube is partitioned into 12 identical cells, each comprising a slot element and a cavity with 1/12 of the cube volume. Although this makes a complicated structure whose bandwidth is limited by the cell cavity electrical volume, the partitioning reduces the mutual coupling to very low levels. Larger polyhedral structures are possible.