This work proposes a novel design of a 4-element MIMO antenna for 5G sub: 6GHz N77/N78 and N79 band applications. The proposed work is designed on a 100 × 100 mm 2 size FR4 defected substrate having a height of 1.6mm, constant of 4.4. Initially, a 30 × 30 mm 2 size single antenna is designed; later, it is extended to a 4-element antenna. Both the antennas work in the range of 3.0GHz to 5GHz and cover the 5G sub:6 GHz bands, which include N77 (3.3-4.2 GHz) and N78 (3.3-3.8 GHz) and N79 (4.4-5.0 GHz). The isolation values above 17.5 dB when elements are placed orthogonal and above 25 dB are attained in the structure's entire working region. High radiation efficiency and gain values are attained due to the systematic design. The proposed antenna is fabricated and checked with the measured results with simulation results. The compared results are almost in good agreement, and these results include S-parameters and diversity performance characteristics. The proposed antenna is designed with a popular and efficient simulator known as Ansoft HFSS.