Design of a Super Wideband MIMO Antenna with Hexa-Notch Interference Suppression and Isolation Enhancement

The demand for Super Wideband (SWB) Multiple-Input Multiple-Output (MIMO) antennas has surged due to their critical role in applications such as radar imaging, cognitive radio, military communications and long-range RF communication systems. However, conventional MIMO antenna designs face challenges such as inter-port coupling, bandwidth constraints and frequency interference, which degrade signal quality and overall system performance. To address these limitations, this research proposes a novel Hexa-Barrier Super Wideband MIMO antenna (HBSWB MIMO) with an [Formula: see text] configuration, designed to enhance isolation, which improves impedance bandwidth and mitigates interference through an advanced multi-stage design approach. The proposed antenna incorporates a four-petal flower-shaped radiator with a sickle-shaped self-complementary structure, crafted from Silver to ensure superconductivity, smooth impedance transitions and enhanced radiation efficiency. To optimize interference suppression, a Hexa-Notch design is introduced utilizing U-shaped slots and C-shaped stubs to filter unwanted frequency bands, including WiMax (3.2–3.8[Formula: see text]GHz), downlink C-band (5.00–6.16[Formula: see text]GHz), INSAT (7.04[Formula: see text]GHz), WLAN (8.09[Formula: see text]GHz), X-band downlink (10.2–11.9[Formula: see text]GHz) and radio navigation bands (24–28[Formula: see text]GHz). Furthermore, a Zenocross-shaped LC decoupling structure is integrated into the antenna feed line to minimize inter-port coupling and improve isolation using stepped inductors and capacitors for frequency-specific impedance matching. The ground plane features an Electromagnetic Band-Gap (EBG) structure, ensuring wideband impedance matching and interference suppression without increasing antenna size. A prototype was fabricated on an FR4 substrate using standard PCB photolithographic techniques, and experimental validation confirmed that the proposed antenna achieves an 85% reduction in mutual coupling, 92% suppression of unwanted interferences and a bandwidth efficiency improvement of 40% over conventional designs. These combined simulation and fabrication results highlight the antenna’s potential for next-generation SWB MIMO communication systems.