Using a circularly polarized antenna is an attractive method for balancing polarization to transmit and receive the antenna. Therefore, this paper explores a wideband 4-port CP multiple-input multiple-output (MIMO) antenna to be used for 5G wireless technologies in the sub-6 GHz range (3.5-5.9) GHz. Also, the polarization diversity between the neighboring radiators is used to achieve high isolation between antenna components, resulting in a low envelope correlation coefficient (ECC). Other MIMO efficiency metrics are analyzed, such as the proposed structure's Diversity Gain (DG), Mean Effective Gain (MEG), and Channel Capacity Loss (CCL). The finding shows that the suggested design's suitability can be considered a possibility for imminent sub-6 5G MIMO applications.