Characterization of Graphene-Based Ink for RF Applications

Carbon based materials (carbon nanotubes, graphene) exhibit interesting physical properties and have been recently investigated in many applications. In the family of carbon allotropes, graphene has attracted particular attention for its exceptional electrical properties. However, graphene as many other carbon based materials, cannot be deposited on substrates in bulk quantities without exploiting solvent casting techniques, by means of inks. In this work, the electrical properties of a graphene-based ink are analyzed. The graphene film is deposited on a gap along a microstrip line with controlled circular pattern geometry. Several prototypes are realized on a RF substrate from Panasonic substrate. The surface impedance of the graphene-based films and their scattering parameters are measured for two different graphene deposition thicknesses. The graphene film is modelled with a lumped element model. The impedance values are used as a first estimation of the sheet impedance in a full-wave analysis.