▎ 摘　　要

The radio-frequency (RF) electrical response of monolayer graphene is reported. From the measured S-parameter in the range of 10 MHz to 50 GHz, a simple equivalent resistor-inductor-capacitor (R-L-C) circuit is established to analyze frequency impedance. The impedance magnitude shows significant frequency dependence only below 10 GHz and this dispersive behavior is originated from the graphene-metal contact. Above 10 GHz, there is no distinctive change in overall characteristic of impedance due to the absence of the skin effect and low intrinsic kinetic inductance of graphene. These results show that graphene could be a promising candidate for high-speed device application. (C) 2009 The Japan Society of Applied Physics