Optimized Low‐Profile Dual‐Band Slot‐Ring MIMO Antenna for 5G mm‐Wave Applications

The study presents a compact four‐port dual‐band MIMO antenna specific to millimeter‐wave (mm‐Wave) 5 G networks that operate at higher frequency intervals of 26 and 39 GHz. The development process of MIMO antennas that operate at higher frequencies is highly challenging, mainly because of the need to simultaneously achieve wider bandwidth, larger radiation efficiency, and lower mutual coupling within a compact structure. To address these challenges, the proposed antenna employs four asymmetrical slot resonators integrated with microstrip‐line feeding structures, enabling efficient dual‐band operation while maintaining a reduced footprint. The proposed approach conducts a detailed parametric study to precisely tune the antenna resonances at the desired operating frequencies. The proposed spatial design of the MIMO antenna is optimized using CST Microwave Studio, and experimental validation is performed using a ‘vector network analyzer’ to verify the critical performance characteristics. The physical measurement results demonstrate stable antenna gains of approximately 5.7–6.0 dBi on the lower frequency band and 6.6–6.9 dBi on the upper frequency band. Further, a high radiation efficiency exceeding 95% in the lower band and remaining above 85% in the upper band is attained. Additionally, the proposed MIMO configuration exhibits excellent diversity characteristics: a very low ECC ≈ 10⁻⁵, CCL of less than 0.30 bits/s/Hz, and a DG of approximately 10 dB, indicating minimal correlation among antenna elements. Overall, the proposed antenna effectively addresses key mm‐Wave MIMO design challenges, offering a reliable and proficient solution for future 5 G wireless systems.