On-Body and SAR analysis of a Polyester Textile antenna for Wearable Applications

Abstract

An polyester substrate textile antenna is proposed for wearable body applications at 4.6 and 5.8 GHz frequencies. The antenna has the required compact design for wearable applications. The X-mass tree-shaped patch, supported by the staircase structure, aids the antenna in operating at treble bands. The antenna's polyester has hydrophobic properties, and the conductive ground patch layers were portrayed by means of the conductive adhesive copper film. A prototype was developed with the polyester material as the substrate, and the total footprints of the antenna are 30x20 mm2. This model was meant for wearable applications, so it was intensively tested in many horizontal and vertical bending positions. Thus the conformability of the antenna was validated. The specific absorption rate (SAR) analysis was also done on a three-level human phantom prototype; comprising muscle, fat and skin. The dual wearable application frequencies of 4.6 and 5.8 GHz applications are validated. The results from the SAR analysis conclude that the antenna is safe to use on the human body with a max SAR of 0.762 and 0.698 w/kg for 1 gram of tissue. The compact design with conformability and safe SAR thresholds aid the antenna for wearable body application.