High-performance graphene wearable THz nano-antenna using a metasurface reflector: dual-band, dual-port, and low-SAR operation

In this study, a wearable, portable, dual-band, two-port antenna built on a flexible polyimide substrate is shown. The two working bands are produced by two ring-shaped graphene-based radiators, and port isolation of more than 25 dB is guaranteed by parasitic circular rings between the radiators. For both 1 and 10 g tissue models, a metasurface (MS) reflector positioned below the radiator increases the gain to 4.95 and 5.85 dBi while concurrently lowering the specific absorption rate (SAR) by more than 85%. By adjusting the graphene layer's chemical potential, frequency reconfigurability is made possible. Full-wave simulations using HFSS and CST indicate steady operation over the 2.25-2.5 and 3.2-3.9 THz regions. Additionally, the antenna performs reliably even when bent, which makes it ideal for wearable THz wireless applications.