A varactor-tuned frequency-reconfigurable fabric antenna embedded in polymer: Assessment of suitability for wearable applications

In this paper, we present a novel class of wearable antennas that are flexible, electronically tunable, and robust. They consist of conductive fabric parts, used as the radiator, with polydimethylsiloxane (PDMS) polymer utilized to form the substrate as well as the full encapsulation of the radiator including its electronic tuning elements. To validate the concept, a prototype that provides frequency tuning from 2.3 to 2.65 GHz has been fabricated and tested. The fabrication process is detailed and experimental investigations on its suitability for wearable applications are presented. To assess the antenna robustness, its reconfigurability under severe physical deformations has been studied through washing the antenna and also by wrapping it on the head and wrist of a UWB human muscle equivalent phantom. The antenna's effect on body has also been investigated through Specific Absorption Rate (SAR) measurement. The results confirm that the antenna is a promising candidate for modern wearable devices.