Four co-located antennas for MIMO systems with a low mutual coupling using mode confinement

Multiple input multiple output (MIMO) systems can drastically improve wireless communication capacity and robustness by exploiting multipath effects. Performances of these multiple antenna systems largely depend on the correlation between received signals. To maximize the capacity, the correlation must be as low as possible. Spatial diversity is usually used to decrease this correlation. The antenna system presented in this paper is composed of four co-located antennas which are able to produce uncorrelated signals by using both magnitude and polarization diversities. Furthermore, the structure is planar and contains a ground plane which is well-suited to be integrated in a communicant terminal. The diversity potential of the structure is quantify by calculating the envelope correlation between each radiation pattern. The coupling between each access has been decreased by using vias for confinement modes.