A closely confined coplanar waveguide (CPW) fed MIMO antenna sheltering the entire ultra-wideband (UWB) spectrum with high isolation as well as dual-band rejection attributes is presented and evaluated. The intended wideband multiple-input multiple-output (MIMO) radiator embodies a pair of similar planar monopole elements (PME) together with the integration of the ingredients like a defected ground structure with Koch fractal boundaries, parasitic strips, cross-linked C-shaped parasitic resonators, and a Hilbert fractal neutralization line. The suggested UWB MIMO antenna houses an extensive bandwidth spanning between 2.64 and 12 GHz, sharply rejecting a pair of bands centered at 3.3 and 4.5 GHz. The wideband diversity antenna is realized in a closely packed measure of 26.50 mm (L) × 29.84 mm (W). A minute inter-element spacing of 0.51 mm is attained with the suggested layout. The numerical and experimental investigations of vital diversity parameters such as the envelope correlation coefficient, mean effective gain, total active reflection coefficient, as well as multiplexing efficiency depict high diversity performance. The consistency amidst the simulation as well as the empirical results recommends the worthiness of the intended antenna for handy UWB and UWB MIMO systems.