A MIMO (Multi-Input Multi-Output) antenna includes a system ground plane, an antenna ground plane, an EBG (Electromagnetic Band-Gap) structure, a first antenna element, and a second antenna element. The antenna ground plane overlaps a first portion of the system ground plane. The EBG structure is formed on a second portion of the system ground plane. The first antenna element and the second antenna element are both disposed in proximity to the EBG structure, but substantially extend in different directions.