X-Band MMIC Balanced Frequency Doubler based on Graphene Diodes

In this paper, we demonstrate the design, fabrication, and characterisation of the first frequency doubler circuit employing graphene diodes. Exploiting the nonlinearity reported for state-of-the-art graphene diodes, a fully integrated, balanced microwave frequency doubler is realised on a 500-μm thick quartz substrate. The presented circuit shows broadband operation from 7-13 GHz and achieves −25.3 dB of conversion gain and −15.3 dBm of output power at an output frequency of 9.2 GHz.