Decoupling design of quadri-polarization overlay antenna element

OPRA (Orthogonal Polarization Reuse Antenna) can reduce the interference in the sector configuration. However, when a lot of antennas are installed horizontally, as in Massive-MIMO, the antenna size becomes large. In this paper, we present the mutual coupling reduction for a quadri-polarization overlay element. Overlay elements is the way to reduce the size of the antenna. The input characteristics and radiation pattern of the proposed antenna are investigated numerically.