“…Therefore, to reduce the back-lobe radiation and to achieve a directional radiation pattern from a slot antenna excitation, several back-lobe reduction techniques were employed in the literature. Such techniques include electromagnetic bandgap (EBG) structures [9,10], isolated surfaces [11], inductor and resistor loading [12,13], ground plane meandering and edge serration [14,15], and using reflector layers in a 3D stacked configuration [5,[16][17][18]. The works presented in [5], and in [16][17][18] are either Yagi-like or Yagi works (not MIMO) and have used slot antenna as the exciting element.…”