In this paper, a compact and low-frequency broadband microwave metamaterial absorber (MMA) based on meander wire structure loaded with lumped resistor has been proposed and investigated numerically and experimentally. Compared with the single meander wire structure, the bandwidth and absorption level of the proposed MMA loaded with lumped resistors can be improved extremely. The retrieved equivalent constitutive parameters and simulated electric and magnetic fields distributions have been demonstrated to illustrate the mechanism underlying observed absorption. The simulated results exhibit that the proposed MMA can keep a good stability in a wide angular range for both transverse electric (TE) and transverse magnetic (TM) waves under normal and oblique incidence. Further simulated results indicate that the performance of the MMA can be adjusted by changing parameters of unit-cell structure and lumped resistors. Finally, we have fabricated a modified MMA sample practically, composing of meander wire structure loaded with lumped resistors, FR-4(loss), foam and continuous metal film. The modified MMA yields absorbance of over 85% from 1.84 GHz to 5.96 GHz in the experiment, and the relative bandwidth is about 105.6%, which is agreement reasonable with simulation.

本文提出了一种基于曲折线结构的集总电阻加载的紧凑型低频宽带微波超材料吸收器，并进行了数值和实验研究。与单曲折线结构相比，建议的带有集总电阻的MMA的带宽和吸收水平可以大大提高。已证明检索到的等效本构参数和模拟的电场和磁场分布可说明观察到的吸收的基本机理。仿真结果表明，所提出的MMA在垂直入射和倾斜入射条件下，在横向（TE）和横向（TM）波均能在宽角度范围内保持良好的稳定性。进一步的仿真结果表明，可以通过更改单位单元结构和集总电阻器的参数来调整MMA的性能。最后，我们实际上制造了一种改性的MMA样品，该样品由曲折的导线结构组成，该导线结构中装有集总电阻，FR-4（损耗），泡沫和连续金属膜。改性MMA在1.84 GHz至5.96 GHz的吸收率达到85％以上，相对带宽约为105.6％，与仿真吻合较好。