Design and Analysis of a High-Isolation Dual-Element MIMO Microstrip Antenna with DGS for 5G and Futuristic Trends of 6G

Abstract

In this work, we present the design evolution and performance evaluation of a compact dual-element MIMO microstrip antenna for mmWave 5G/6G applications. Starting from a basic patch geometry on Rogers RT5880 substrate, the design employs a dual-modification strategy: slot-loading the radiating patches to precisely tune the resonance and enhance gain, combined with multiple defected ground structures (DGS) to suppress mutual coupling and broaden the bandwidth. The antenna exhibits excellent reflection coefficients (S11, S22) below –25 dB at 27 GHz. Its -10 dB impedance bandwidth (VSWR < 2) is 1.312 GHz centered at 27 GHz. At 27 GHz, it achieves a VSWR of ~1.116, realized gain of 10.45 dBi, total efficiency of 78.5%, and directional radiation with half-power beamwidths of 50.0° (H-plane) and 34.1° (E-plane). These results demonstrate that the proposed antenna offers compact size, high isolation, excellent MIMO performance, and enhanced bandwidth, making it a strong candidate for next-generation mmWave wireless systems.