▎ 摘 要
Graphene-based artificial magnetic conductor (AMC) structures featuring wideband and tunable responses at terahertz frequencies are presented. The unit cells of the proposed structures comprise curved coupled microstrip line (CCML) resonators, in which small graphene patches are added for electrical tuning. An advantage of the present structure is that the full range of graphene chemical potential, from 0 to about 1 eV, can be used to tune the center frequency; therefore the AMC is tunable in a larger frequency range, for which the return loss remains near 0 dB. This feature is missing in the previous tunable graphene-based AMC structures. A typical design in the present work yields a fractional bandwidth of 45% and an electrically tunable center frequency in a range from 3.7 to 4.4 THz.