This research focuses on the design of a super wideband (SWB) antenna and its two-port multiple input multiple output (MIMO) configurations. The antenna is designed to cover the wideband spectrum ranging from 1.42GHz to 40GHz, with the additional feature of tri-notch band functionality. The respective band spectrums of 3.5GHz, 5.8GHz, and 10.5GHz, which are worldwide assigned for 5th generation (5G), sub-6-GHz applications, Wireless local area network (WLAN), Industrial Science and Medical (ISM) applications and X-band are notched utilizing different shapes of slots. The SWB is achieved by converting a broadband circular monopole into an asymmetric semicircular monopole offering wideband, which is then modified by implementing the tapered line feed techniques. Furthermore, to reduce the mutual coupling among the MIMO elements, a T-shaped open-ended stub is loaded between them and optimized to achieve a low mutual coupling of ≤-20dB. Along with that, various MIMO performance parameters are studied and their comparison with the measured results is compared. Lastly, a comparison table is produced to indicate the competence of the suggested work in comparison to the state-of-the-art, which strengthens the provided conclusions.