Evolutionary Design of Compact Monopoles Embedded MIMO Antennas With DMS Coupler for Wide/Dual/Triple Band Functionality in 5G Sub-6 GHz Bands

A monopole MIMO antenna plays a crucial role in modern wireless applications by offering high data rate transmission, compact size, and low-profile design, owing to its dependability and channel capacity. However, one of the main challenges in handheld devices is the decline in radiation efficiency, which falls nearly 50% as the number of antenna elements increases in MIMO systems. To address this issue, a novel two-port MIMO monopole antenna with an E-shaped defected microstrip structure (DMS) and dumbbell-shaped metamaterial is proposed. This design enhances performance for modern wireless technologies. The antenna, incorporating two L-shaped slots, operates at three resonant frequencies (3.65, 4.6, and 5.65 GHz), making it suitable for integration into handheld devices. The compact antenna is analyzed using performance metrics such as reflection coefficient, VSWR, gain, ECC, DG, and TARC. Results show reflection coefficients of −28.08 dB at 3.70 GHz, −26.68 dB at 4.80 GHz, and −15.37 dB at 5.60 GHz. Additionally, the antenna achieves ECC values below 0.2, DG values of 9.83 dB, and TARC values lower than −13.87 dB. With its compact size, multi-band operation, and high data rate capabilities, the proposed antenna is well-suited for applications in 5G, Wi-Fi, Bluetooth, and other modern wireless technologies.