Multiband and Low-Specific-Absorption-Rate Wearable Antenna With Low Profile Based on Highly Conductive Graphene Assembled Film

A flexible tri-band antenna with low profile and low specific absorption rate (SAR) based on highly conductive graphene assembled film (GAF) is proposed. The antenna incorporates GAF with polydimethylsiloxane to provide the flexibility for wearable applications. To reduce the effect of backward radiation on human body, a new multiband artificial magnetic conductor (AMC) reflector is proposed, which consists of several circular patches. The measured operating bandwidths of GAF antenna include 2.26–2.46 GHz (WiFi band), 3.52–3.68 GHz (5G n77 band), and 4.94–5.26 GHz (5G WLAN band). Correspondingly, the realized gain varies from 5.7–7.9 dBi. The proposed GAF antenna shows good flexibility and radiation stability when loaded on human body. The simulated SAR peak value is 0.51 W/kg at 2.36 GHz, 0.61 W/kg at 3.6 GHz, and 0.562 W/kg at 5.1 GHz when the tissue is 1 g, which meets the international standard. All results demonstrate that the proposed flexible GAF tri-band antenna is suitable for integrating in wireless wearable communication system.