Circularly Polarized Wearable Antenna With Low Profile and Low Specific Absorption Rate Using Highly Conductive Graphene Film

A low-profile circularly polarized wearable antenna with flexible performance and reduced specific absorption rate (SAR) based on graphene is presented. The antenna adopts highly conductive graphene film and polydimethylsiloxane substrate, which have good flexibility, mechanical stability, and light weight. The wearable antenna operating at 5.8 GHz with a profile of 0.05 λ is designed and fabricated, which retains a reflection coefficient of less than -10 dB when loaded on the human body. The measured results indicate the axial-ratio (AR) bandwidth for AR<; 3 dB covers 5.75-5.83 GHz with the realized gain varying from 5.0-6.1 dBic. The SAR peak is 1.02 W/kg when the human tissue is 1 g and 0.947 W/kg when the human tissue is 10 g, which meets the international SAR standards.