A novel compact four-port MIMO dielectric resonator antenna with wideband operation for 5G mm-wave applications

Abstract This work presents a compact wideband four-port Multiple-Input Multiple-Output (MIMO) Dielectric Resonator Antenna (DRA) for 5G applications in the millimeter-wave (mm-wave) band. The proposed MIMO structure comprises of four hexagonal dielectric resonator antennas (DRAs) mounted on a ground plane supported by a substrate, utilizing aperture-coupled microstrip feeding for excitation. Notches are incorporated at the center of the DRAs, enabling the excitation of multiple-resonant modes for achieving a wide bandwidth. Mutual coupling is reduced by employing a combination of isolation techniques, including polarization diversity, a defected ground structure (DGS), and metallic strips placed along the DRA sidewalls. The antenna operates over frequency band ranging between 22.99–30.49 GHz (28%) with maximum isolation greater than 33 dB. The achieved peak gain and radiation efficiency are 8.53 and 94.4% respectively. The design maintains a compact overall size of 1.60 λ o × 1.60 λ o × 0.20 λ o. The design approach is presented, emphasizing the effectiveness of the implemented isolation techniques. A prototype is developed and tested, demonstrating results that closely align with the simulations. The proposed MIMO antenna exhibits wideband operation, high isolation, and compactness, making it a promising candidate for modern 5G mm-wave MIMO systems.