In this paper, a metamaterial absorber based on graphene is proposed, designed and simulated numerically using multilayer structures. Before describing our work, the performance response of a three-layer structure is studied concerning one cylinder as a unit cell. Then, by varying the chemical potential of graphene (Fermi level of graphene) by applying external potential, the center frequency of this absorber can be adjusted. We will prove that by increasing the number of cylinders as fundamental elements in the unit cell, the bandwidth is also adjustable. Also, the center frequency can be affected by changing the dimensions of fundamental elements. Considering the above-mentioned items, the structure is investigated through increasing the graphene layers in which the absorber’s frequency response is wider respected to previous structures and the center frequency is adjustable as a result of variations in the chemical potential of graphene layers. It is shown that the proposed perfect absorber’s central frequency shift through graphene’s voltage variation is about 0.15 THz which can be increased to 0.3 THz by changing radius. In some of the introduced absorbers, the maximum value of the absorption has reached over 95%. The most important advantage of the proposed structure, which is the main purpose of designing terahertz metamaterial absorbers, is its adjustable bandwidth and center frequency, and simple fabrication.

本文提出了一种基于石墨烯的超材料吸收器，并利用多层结构对其进行了设计和数值模拟。在描述我们的工作之前，研究了以一个圆柱体为单位单元的三层结构的性能响应。然后，通过施加外部电势改变石墨烯的化学势（石墨烯的费米能级），可以调节该吸收体的中心频率。我们将证明，通过增加单位单元中作为基本元素的圆柱数，带宽也是可调的。同样，中心频率可以通过改变基本元件的尺寸来影响。考虑到上述各项，通过增加石墨烯层来研究该结构，其中吸收体的频率响应相对于以前的结构更宽，并且由于石墨烯层的化学势的变化，可调整中心频率。结果表明，通过石墨烯的电压变化，理想吸收体的中心频率偏移约为0.15 THz，通过改变半径可以将其提高到0.3 THz。在某些引入的吸收器中，吸收的最大值已达到95％以上。设计太赫兹超材料吸收体的主要目的是所提出结构的最重要优点是其可调节的带宽和中心频率，并且制造简单。结果表明，通过石墨烯的电压变化，理想吸收体的中心频率偏移约为0.15 THz，通过改变半径可以将其提高到0.3 THz。在某些引入的吸收器中，吸收的最大值已达到95％以上。设计太赫兹超材料吸收体的主要目的是所提出结构的最重要优点是其可调节的带宽和中心频率，并且制造简单。结果表明，通过石墨烯的电压变化，理想吸收体的中心频率偏移约为0.15 THz，通过改变半径可以将其提高到0.3 THz。在某些引入的吸收器中，吸收的最大值已达到95％以上。设计太赫兹超材料吸收体的主要目的是所提出结构的最重要优点是其可调节的带宽和中心频率，并且制造简单。