We have proposed a multiband operated superlative MIMO antenna structure. The simple T-shaped resonator-based design is numerically investigated for the 4 GHz to 20 GHz frequency range. The performance of the design is done in terms of reflectance coefficient, transmission coefficient, radiation pattern, gain, and electric field. The design provides the four-band behaviour. The results represent a minimum S11 of -27.27 dB, a peak gain of 9.66 dB, an E-field of 20041 v/m, and broad directivity. The design is fabricated using the Roger RT Duroid 5880. The presented structure's performance also examines ECC, TARC, DG, and CCL. The reliability of the design is checked by comparison among simulated and measured results. The design helps the airborne, Naval radar and many wireless communication applications.