设计、仿真并实验验证了基于宽边耦合螺旋结构的低频小型化超材料吸波体.实验测试结果表明,该超材料吸波体在1.39GHz吸收率达到最大为98%,其单元尺寸和总厚度均为6.8mm,约为1/32工作波长,实现小型化窄带吸波.由于吸波体中螺旋结构是旋转对称排列的,因而其对垂直入射电磁波的极化方向是不敏感的.此外,该超材料吸波体对斜入射横电和横磁极化电磁波在60时,仍具有强吸收.
In this paper, we present the design, simulation, and experimental demonstration of a miniaturized low-frequency metamaterial absorber based on the broadside-coupled spiral structures. The tested results indicate that the metamaterial absorber can achieve a miniaturized narrowband absorption with a peak absorption of 98% at 1.39 GHz. Both of the unit cell size and the total thickness of the metamaterial absorber are 6.8 mm that is approximately 1/32 of the working wavelength. Since the spiral structures of the metamaterial absorber are arranged in rotational symmetry, the absorber is polarization-insensitive to the normal incident electromagnetic wave. Additionally, the metamaterial absorber can strongly absorb the obliquely incident electromagnetic wave for both transverse electric and transverse magnetic polarizations, even at 60° angle of incidence.