LOW FREQUENCY BEHAVIOR OF CVD GRAPHENE FROM DC TO 40 GHZ

Electromagnetic behaviour of chemical vapor deposition (CVD) graphene at low frequencies is still a mystery. No conclusion is made from the experimental point of views. We systematically investigate the electromagnetic response of graphene at microwave frequencies, which are from direct current (DC) to 40 GHz. Both a coplanar transmission line embedded with different-sized graphene flakes of 48 × 48 and 48 × 240μm2 and a microwave termination based on the graphene sheet of 6 × 6 mm2 are manufactured through standard microfabrication procedures. We conclude that CVD graphene behaves as a frequency-independent surface resistance at the microwave frequencies, which is consistent with the theoretical model by rigorously solving the Maxwell’s equations with the Kubo formula. The work offers a simple, accurate, and conclusive electromagnetic analysis to graphene and thus is of great help to design graphene incorporated microwave components and devices.