Metasurface integrated dual polarized all textile antenna for WBAN application

Abstract This paper presents a dual-polarized textile antenna with an integrated polarization conversion metasurface (PCM) for Wireless Body Area Network (WBAN) applications. The proposed quad-band antenna design achieves linear-to-circular polarization conversion at 1.9 GHz and 6.1 GHz through a 5 × 5 PCM, enabling enhanced circular polarization performance. The PCM unit cell comprises two square rings with plus-shaped metal strips constructed with copper polyester taffeta fabric (CPTF) on a flexible textile substrate, such as jeans. The antenna operates across four bands: GSM1900 (1.9 GHz), LTE (2.8 GHz), WLAN (5.2 GHz), and Wi-Fi 6E (6.1 GHz). Textile PCM antenna underwent theoretical evaluation, numerical optimization, and parametric investigation, resulting in a 3 dB axial ratio bandwidth of 1.75–2.05 GHz (15%) and 5.97–6.28 GHz (5.3%), validated by measurements. The compact antenna design 0.45 λ 0 × 0.43 λ 0 × 0.0054 λ 0 mm 3 is positioned above 15 mm PCM, which has a dimension of 0.63 <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:msub> <mml:mrow> <mml:mi>λ</mml:mi> </mml:mrow> <mml:mrow> <mml:mn>0</mml:mn> </mml:mrow> </mml:msub> </mml:math> × 0.63 <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:msub> <mml:mrow> <mml:mi>λ</mml:mi> </mml:mrow> <mml:mrow> <mml:mn>0</mml:mn> </mml:mrow> </mml:msub> </mml:math> × 0.11 <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:msub> <mml:mrow> <mml:mi>λ</mml:mi> </mml:mrow> <mml:mrow> <mml:mn>0</mml:mn> </mml:mrow> </mml:msub> </mml:math> mm 3 . The antenna achieves a 95% gain increase at 6.1 GHz, a front-to-back ratio of up to 6.6 dB, and a substantial reduction in SAR levels (by 95%) due to the PCM’s effect when positioned 5 mm from the human body. The design’s robustness is demonstrated under bending conditions, with Specific Absorption Rate (SAR) analysis showing safety for WBAN use. Simultaneous linear and circular polarization, gain enhancement, improved front-to-back ratio, and reduced SAR impact make this antenna highly suitable for wearable applications.