Characterization of Tunable Multilayer Graphene Ink by a Microstrip Transmission Line

This paper presents microwave characterization of multilayered graphene in the frequency range of 8–12 GHz. Thru, Reflect, Line calibration method has been used to shift calibration planes from the edge of a microstrip line to graphene. Transmission coefficient is measured for varying bias voltages. Values of complex impedance of graphene are derived from the transmission coefficient. Prototypes have been fabricated consisting of a microstrip line with different gaps on which multilayered graphene ink is deposited. By decreasing the gap size in the microstrip line, the resistance, reactance and the tuning range of graphene decreases.