Microwave Characterization of Graphene Films for Sensor Applications

Graphene is a monolayer of carbon atoms with remarkable electronic and mechanical properties amenable to sensor applications. While the plasmonic nature of graphene at terahertz frequency has been widely reported, investigations on the practical utility of graphene at the microwave frequencies used in wireless sensor nodes are sparse. In this paper, graphene films with different amounts of graphene (12.5 wt%, 25 wt%) are characterized at the microwave frequencies. Dielectric spectroscopy is used to study variation in surface impedance of the film. A simple circuit model of the film based on lumped elements is obtained by fitting the measured scattering parameters with the ADS simulations on graphene loaded microstrip lines.