Design of a graphene loaded slot antenna with 100∶1 bandwidth for wireless sensor applications

Graphene is a monolayer of carbon atoms which exhibits remarkable electronic and mechanical properties amenable to photonic and sensor applications. While the plasmonic nature of graphene at terahertz frequency has been widely reported, investigations on the practical utility of graphene in antennas have been very sparse. In particular, losses in graphene significantly limit the radiation performance of microwave antennas fabricated entirely using graphene. In this paper, a dual-port printed slot antenna is designed with graphene film used as an overlay in the microstrip feed line for broadband impedance matching. Antenna losses are minimized by confining the film to a small area outside the radiator. Through simulations, the effect of varying the surface impedance of the graphene film is parametrically examined to demonstrate 100% impedance bandwidth centered at 3.5 GHz. The proposed antenna design, selectively using graphene away from the antenna surface, is very attractive to configuring low-power wireless sensor nodes.