An FSS Based Multiband MIMO System Incorporating 3D Antennas for WLAN/WiMAX/5G Cellular and 5G Wi-Fi Applications

A compact 3-dimensional dual-element, multiband antenna for Multi-Input-Multi-Output (MIMO) applications is proposed in this paper. Folding technique along with various impedance matching structures are employed for miniaturization and multiband operation while maintaining the desired S-parameter performance. A grid of Frequency Selective Surface (FSS) patch based decoupling structure is introduced to achieve measured isolation of more than 30 dB between antenna ports. In addition to this decoupling structure, a meandered line based defected ground plane configuration helps to retain the multiband response while maintaining the optimum isolation performance. This 3D-MIMO antenna is fabricated and measured for its performance in different bands of WLAN, WiMAX, 5G cellular and 5G Wi-Fi along with different MIMO performance parameters. The reported design is a suitable option for multiband MIMO applications for future wireless technologies.