Low Mutual Coupling of Hexagonal Bar Slotted Dual-Band Four-Port MIMO Textile Antenna for WBAN and 5G Applications

The paper presents a methodology to reduce Mutual Coupling (MC) in a 4-port dual-band Multiple-Input-Multiple-Output (MIMO) textile antenna, specifically designed for biomedical applications. This antenna utilizes MIMO technology and operates within the Wireless Body Area Network (WBAN) and Fifth Generation (5G) across two distinct frequency bands: 2.45 GHz and 3.5 GHz. The structure comprises four octagonal patch antennas, each incorporating a bar and hexagonal slot, with individual patch dimensions of 48.5 x 30 mm. A hybrid approach to minimize MC is investigated for patches positioned at a proximity of 0.15λ. The antenna is evaluated with bending conditions in different curvature angles to test its robustness in practical on-body. The antenna achieves the MC of -30 dB and a maximum realized gain of 2.42 dBi at the lower band and 5.6 dBi at the upper band. Notably, the antenna’s performance exceeds the expected attenuation effects caused by the lossy nature of the human body, indicating a good agreement between the modeled and experimental results.