A Spatially Selective and Electromagnetically Tailored Low-Profile High-Gain Notched UWB MIMO Antenna for 5G and Ultra-Wideband Wireless Systems

This research proposes a spatially selective, electromagnetically tuned, low-profile, high-gain, notched ultra-wideband (UWB) multiple-input multiple-output (MIMO) antenna embedded with a Frequency Selective Surface (FSS) for enhanced performance. The recommended approach integrates a compact FSS-based isolation mechanism into the antenna structure, supporting concurrent improvement both isolation and gain without increasing system complexity, contrasted to conventional designs. The antenna functions over a wide frequency spectrum of 3.1–10.6 GHz, with a fractional bandwidth of 116%. A 5.5 GHz notched band is implemented to efficiently limit interference from WLAN/WiMAX systems. Utilizing orthogonal element placement alongside embedded circular ring structured FSS significantly enhances isolation and improves gain from 4.7 dBi to 7 dBi. The presented 4-port MIMO antenna provides consistent diversity performance by maintaining stable radiation characteristics, high efficiency, and a low envelope correlation coefficient (ECC). The design is suitable for high-data-rate UWB and next-generation 5G wireless applications, especially in portable and handheld devices, due to its compact design, integrated isolation technique, and interference mitigation capability.