This paper introduces the design and experimental analysis of an eight-port Ultra Wide Band (UWB)/Super Wide Band MIMO antenna with the with triple-band rejection characteristics. The proposed UWB design includes a square-shaped radiator and a shared partial ground with novel hexagonal-ring type fencing decoupling structure to achieve UWB and a high degree of isolation between radiating elements. The partial ground with hexagonal-ring type fencing is employed to achieve a broad impedance matching of 7.4 GHz (3.1–12 GHz), while the notch bands are realized at 5 GHz (4.6 to 5.9 GHz), 8 GHz (7.70–8.43 GHz), and 10.5 GHz (10.3–10.98 GHz) by using Substrate Integrated Waveguide(SIW) based metallic via integration of hexagonal and semi-hexagonal parasitic slot stub with radiator. The band notch band characteristics obtained autonomously without modifying antenna performance. The fabricated antenna is having a very compact size of mm. The important antenna characteristics of proposed antenna, such as bandwidth (7.4 GHz), isolation (>20 dB), gain(0-7.5), efficiency(80%), radiation pattern, Envelop Correlation Coefficient(ECC)(0.015), Total Active Reflection Coefficient (TARC) and Channel Capacity Loss (CCL) are examined.