Development of a 5G-Optimized MIMO Antenna with Enhanced Isolation Using Neutralization Line and SRRs Metamaterials

Abstract

This paper presents the design of a Multiple Input Multiple Output (MIMO) antenna intended for 5G wireless applications operating in the 3.5 GHz frequency range. The MIMO system consists of two adjacent antennas, measuring 100 mm × 80 mm × 1.6 mm, with spacing between radiating elements equal to one-eighth of the wavelength (λ/8). The antenna is constructed on an FR4 substrate with a permittivity of 4.3, and a microstrip line is employed for feeding the patch. Several techniques are employed to enhance the isolation between the antennas. Specifically, two decoupling methods are explored: the use of a neutralization line (NL) and the incorporation of metamaterial split-ring resonators (SRRs). Simulation results demonstrate substantial isolation, exceeding 20 dB with SRR implementation and more than 23 dB with the NL approach. Both individual antennas and the MIMO configuration are simulated, analyzed, and then physically fabricated for measurement, exhibiting good agreement between measured and simulated results. The study investigates the impact of each technique on antenna to determine the optimal configuration for the applications of 5G and IOT in different fields such as health (wireless medical telemetry systems (WMTS)). Remarkably, the introduction of metamaterial (MTM) with SRRs achieves a noteworthy reduction of mutual coupling by 23 dB while minimizing the mutual coupling to about 23 dB with NL insertion.