Three-Element MIMO Antenna System With Pattern and Polarization Diversity for WLAN Applications

In this paper, a three-element compact multiple-input-multiple-output (MIMO) antenna system having both pattern and polarization (linear/circular) diversity is proposed. The proposed MIMO system consists of a chamfered-edge square patch antenna with an offset feed that provides circular polarization in broadside direction. Furthermore, two printed dipole antennas are placed adjacent to it for providing linearly polarized endfire radiation. The three-element MIMO antenna system exhibits good isolation (>15 dB) without the use of any separate decoupling structure. The match between the simulated and measured results on fabricated antenna prototype suggests that the proposed antenna can be a good candidate for pattern-and polarization-diversity MIMO applications in the 5.8-GHz WLAN frequency range.