Miniaturized Low-Interference CPW-Fed MIMO Antenna on Jeans Textile for Wearable Biomedical Applications in the 5.8 GHz ISM Band

Abstract

In this work, a compact dual-port CPW-fed textile monopole MIMO patch antenna is proposed for biomedical applications operating in the 5.8 GHz ISM band. The antenna integrates split-ring resonator (SRR) based metasurfaces and is fed by a 50-ohm standard coplanar waveguide. The radiating elements are fabricated on a jeans textile substrate, experimentally characterized with a relative permittivity of 1.6 and a thickness of 1 mm. The overall antenna structure, including the SRR configuration and inter-element spacing, is optimized using CST Studio Suite to enhance impedance matching and minimize mutual coupling between elements. The proposed antenna occupies a compact area of 54 mm × 25 mm. The simulated impedance bandwidth ranges from 4.87 GHz to 7.21 GHz, while the measured bandwidth extends from 4.35 GHz to 7 GHz. The antenna demonstrates high isolation with a simulated S<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">12</inf>/S<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">21</inf> lower than -15 dB and achieves a peak gain of 7.05 dBi. Furthermore, key MIMO performance metrics such as Envelope Correlation Coefficient (ECC), Channel Capacity Loss (CCL), Diversity Gain (DG), Mean Effective Gain (MEG), and Total Active Reflection Coefficient (TARC) confirm the suitability of the antenna for wearable biomedical devices operating in the 5.8 GHz ISM band. These features highlight the potential of the design for reliable body-centric wireless communication.