Impact of Various Wearability Conditions on the Performances of Meander-Line Z-Shaped Embroidered Antenna

Abstract

The field of wearable computing technology describes the future of electronic systems being an integral part of our everyday clothing with various enhanced functionalities. The present work is aimed at making closer steps towards the real wearability of electronics using textiles. We designed a fully-textile meander line Z–shaped monopole antenna for radio-frequency (RF) harvesting and for short-range communication purposes in the body-area network for various wearable applications. The target antenna was designed in the Ansys HFSS software tool and fabricated on a single-layer cotton textile using silver conductive threads and an embroidery technique. The antenna was characterized using a vector network analyzer (VNA), and the selected design was found to be nearly invariant under different deployment conditions. Antenna performance was studied by measuring the return loss while the antenna was in close proximity to the human body, or under various bending scenarios and/or wet conditions with sweat. The simulated return loss was −20.36 dB at an operating frequency of 1.62 GHz, and the measured return loss for the fabricated antenna was −19.45 dB at 1.6275 GHz with a −10 dB bandwidth of 100 MHz (i.e., 1.58 GHz to 1.68 GHz), and a fractional bandwidth of 6.17%. The results of this study are very important for the design of future wearable antennas in the new concept of the Internet of bodies.