Planar Yagi MIMO Antenna Array with Improved Isolation for 5.8GHz WLAN Application

In this paper, pattern-diversity (PD) decoupling technique is incorporated with defected ground structure (DGS) for a planar two-port Yagi multiple-input multiple-output (MIMO) antenna array. By placing two planar Yagi elements adjacent to each other symmetrically and adjusting the horizontal position of four directors, the desired pattern diversity is obtained. And etching a pair of semi-circle ring slots placed outside the two excitation dipoles into the shared ground plane, allows the isolation of more than 25 dB through the whole frequency bandwidth (5.5-6.1 GHz). The proposed MIMO antenna is manufactured on the FR-4 substrate, which is cost-effective and easy to be implemented in a MIMO system for 5.8 GHz WLAN application.