In order to increase its impedance bandwidth, this research article proposes a MIMO 5G antenna and an inset feeding method. The unique feature of the proposed antenna lies in its capability to operate at a frequency of 28 GHz. A complementing split ring rectangular resonator that is precisely positioned on a modified ground plane is part of its unique design. This novel method in this design improves the antenna’s performance, allowing it to efficiently and accurately broadcast and receive information. The antenna’s performance is optimized by the incorporation of the resonator and the defective ground plane, making it a potential option for advanced wireless communication systems. The antenna is mounted on a FR4 epoxy substrate with physical dimensions of 40 mm × 40 mm × 0.8 mm. Four identical patches with triangle cuts are stacked orthogonally to form the MIMO 5G antenna design. This research introduces a MIMO 5G antenna, utilizing triangular cuts and inset feeding for enhanced impedance matching and increased gain to 5 dBi. It covers a broad 7 GHz bandwidth, from 25.5 to 32.5 GHz in the 5G band. This antenna demonstrates promising potential for improved performance in 5G communication systems. A built antenna prototype is thoroughly tested to confirm the modelling results. This meticulous verification method ensures that the measured result matches the simulation results, validating the design’s reliability and accuracy.