A small size of 18 mm × 34 mm antenna is structured as MIMO (multiple input multiple outputs) and studied for double sharp rejection of notch bands for reliable ultra-wide band (UWB). It is used to present switches at the Wireless-LAN and IEEE INSAT-Mega Expanded C-based antenna slot, which is fed via a tapered slit that looks like an inverted L-shape. Coupling is < -22 dB over an operating range of 2.93 to 20 GHz, and the efficiency drops at the center of this band indicating good interference suppression performance. The structure's remoteness among ports, radioactivity patterns, effectiveness, comprehended gain, envelope coloration ecoefficiency (ECC), statistical real gain (SRG), and entire energetic replication coefficient are all considered in this research (TARC). This proposed methodology providing VSWR of 23%, S11 of 42%, return loss of 12%, gain of 21%, the directivity of 17%, efficiency of 41%, and radiative power of 9% had been improved. Finally, the proposed MIMO antenna can offer 5G-level operation with an effective tempered size with emphasize efficiency. [ABSTRACT FROM AUTHOR]