Design of a compact, highly flexible, high-performance wideband all-textile antenna for wearable and portable IoT devices

Abstract

The increasing adoption of wearable electronic devices across various sectors has driven significant research into flexible radio frequency (RF) antennas to overcome the limitations of traditional metal-based antennas. The demand for lightweight, flexible, and low-profile designs highlights the necessity for innovative solutions in portable electronics. This work proposes a compact, broadband omnidirectional monopole antenna for wearable applications, incorporating a slotted ground plane to enhance both impedance bandwidth and omnidirectional radiation characteristics. The antenna design was developed using Computer Simulation Technology (CST) software and validated through ANSYS HFSS, demonstrating strong agreement between the results from both simulation software. The antenna was fabricated using a felt fabric substrate and e-textile conductive materials, providing excellent flexibility, lightweight properties, and seamless integration into garments. The fabricated prototype, measuring 80 mm × 57 mm × 1 mm, achieved a measured impedance bandwidth of 118% (1.78–7 GHz). The gain varies between 2.17 dBi and 8.9 dBi, while the efficiency ranges from 85 to 97% over the operational frequency range, making this antenna a promising candidate for high-data-rate and efficient communication links. Structural deformation tests confirmed the antenna’s stable performance under mechanical stress and human body loading. Additionally, the simulated specific absorption rate (SAR) values remained within FCC limits, validating the antenna’s safety for wearable applications. A potential healthcare application involves integrating the antenna into a doctor’s chest badge, which could replace manual card swiping, improve convenience, and reduce bacterial contamination risks. Overall, this antenna offers significant potential for advancing wearable communication systems and medical technology.