Graphene-Based Antenna for the Design of Modulated Scattering Technique (MST) Wireless Sensors

This letter proposes the use of graphene-based antenna for the design of modulated scattering technique (MST) wireless sensors. The antenna impedance is changed to produce a modulation in the backscattered field by means of an electrostatic bias field, which generates a change in the graphene chemical potential. Such behavior of a graphene antenna replaces the adoption of expensive microwave switches and reduces sensor dimension and complexity as well. A preliminary prototype of the MST-based graphene sensor working in the X-band at 10 GHz has been designed, fabricated as proof of concept. The obtained preliminary results demonstrate the feasibility of such kind of sensors. The X-band prototype shows very low performances with respect to standard metallic antenna due to the low radiation efficiency of graphene at microwave frequencies. However, it demonstrates that these methodologies could play a key role for millimetric and terahertz (THz) frequencies bands, where the standard metallic antennas and microwave switches cannot operate, while graphene offers the good performances.