Isosceles Triangle MIMO Antenna for Simultaneous 5G Communications

A four-element compact planar MIMO antenna is developed for the 3.5 GHz 5G sub-6 GHz band, ensuring reliable radiation performance and enabling simultaneous downlink and uplink communication. The proposed MIMO system incorporates four isosceles triangular elements, where two are allocated for uplink and the other two for downlink. Its compact structure facilitates simultaneous communication with separate provisions for uplink and downlink operations. An FR4 substrate has four antennas printed orthogonally to minimize mutual interaction between the elements. Triangles are more isolated and efficient when their corners are trimmed. Cutting the semi-circle yields the desired resonance frequencies. The proposed MIMO system measures 90 x 90 x 1.6 mm3. The performance of the proposed system was evaluated using multiple metrics, including far-field radiation patterns, S-parameters, channel capacity loss, envelope correlation coefficient, peak gain, diversity gain, and radiation efficiency. The simulated results closely aligned with the measured data, demonstrating strong agreement.