Full Polarization Transformation Using Graphene in Microwave Frequencies

Polarization manipulation plays an important role in real applications. In this article, full polarization transformation using graphene has been first achieved in microwave frequencies. Without the aid of lumped elements like varactors or p-i-n diodes and without changing the geometrical parameters of the structure, the polarization conversion such as linear to linear, linear to circular, and linear to elliptical can be realized simultaneously by only changing the sheet resistance of graphene. Furthermore, based on the transmission line (TL) model, the relationship between polarization states and different sheet resistance of graphene has been investigated in detail. Four prototypes have been fabricated based on the chemical vapor deposition (CVD) -grown graphene, which has the desired sheet resistance of 10, 150, 300, and 1000~\Omega /sq. Both the full-wave simulated results and measured results demonstrate that our structures can efficiently perform the function of polarization transformation by varying the sheet resistance of graphene, which reveal that graphene has great potential for microwave manipulation.