Using characteristic mode analysis (CMA), this paper introduces a novel approach to antenna design for MIMO (Multiple Input-Multiple Output) systems in the context of 5G applications. This method allows for the reduction of antenna dimensions while increasing their efficiency, which is crucial for modern equipment.With a core frequency of 3.6 GHz, the proposed antenna consists of a small array of 4 x 4 slot-modified patches.The patches are supplied using a coupling slot, a configuration that facilitates the modification of surface currents to improve radiation efficiency and optimize performance over a wide frequency range.. The results show that the antenna has a bandwidth of 750 MHz, covering the frequency range from 3.1 to 3.85 GHz, and a gain of 4.84 dB. The reduced dimensions of this antenna (108 × 108 × 3.2 mm 3) make it a suitable option for space-restricted environments. What’s more, the design is fully compliant with MIMO system specifications. Antenna components can be arranged close together without affecting their radiation characteristics. Experiments carried out on a 4 × 4 MIMO configuration show significant isolation between elements, exceeding 27 dB, as well as an extremely low envelope correlation coefficient of less than 2.8 × e -8. These attributes make this antenna an efficient, space-saving option for the massive MIMO networks of 5G technology, satisfying the high requirements in terms of bandwidth, gain and integration in contemporary wireless systems.