Wideband MIMO Antenna for Wi-Fi 7 and 6G Applications

Abstract

The rapid progress of Wi-Fi 7, sub-6 GHz fifth-generation (5G), and future sixth-generation (6G) wireless communication systems necessitates compact Multiple-Input Multiple-Output (MIMO) antennas with wide impedance bandwidth, high isolation, low mutual coupling, and enhanced diversity performance. However, the existing small MIMO antenna designs are constrained by fundamental trade-offs between bandwidth, isolation, port count and antenna size, which limit their application in the next-generation high-speed wireless devices. In this paper, a compact four element flower-shaped wideband MIMO antenna with orthogonal element arrangement, optimized inter-element spacing, T-shaped decoupling structure and Defected Ground Structure (DGS) is proposed to effectively suppress surface currents and electromagnetic coupling. The flower-like radiating structure increases the effective current path length, allowing all kinds of resonant modes and reliable dual-band wideband operation in a compact footprint of 96 x 96 x 1 mm3. Comprehensive electromagnetic calculations and experimental assessments are performed to evaluate the antenna performance in terms of reflection coefficient, isolation, gain, radiation pattern, Envelope Correlation Coefficient (ECC), Diversity Gain (DG) and Mean Effective Gain (MEG). The proposed antenna has wide operating bandwidth of 2.60-5.60 GHz and 5.70-11.10 GHz, minimum reflection coefficient of -65 dB and isolation between adjacent ports of 65 dB. The optimized configuration has an ECC of 0.01, a DG of nearly 9.9 dB, good matching, stable circular polarization characteristics, and nearly omnidirectional radiation patterns. The measured S-parameter results show a good agreement with the simulated results, which confirms the accuracy and practical feasibility of the proposed design. The proposed flower-shaped design achieves better bandwidth, isolation, compactness and diversity performance compared with traditional compact MIMO antennas without increasing structural complexity. These characteristics make the antenna a possible candidate for Wi-Fi 7, Internet of Things (IoT), sub-6 GHz 5G and future 6G wireless communication systems that require reliable high data rate and multi-channel communication. Keywords—antenna Design, Mobile communications, 6G, flower MIMO Antenna, GHz, Wireless System