Transmittance Properties of Metallic Double-Coil Array as Terahertz Absorber

An array of tungsten double coils embedded in polyester resin was investigated as an electromagnetic wave absorber. The finite element method was used to numerically find the best structure of the coils. Then, the transmittance response of the sample was evaluated experimentally using terahertz time-domain spectroscopy. Results show that such double-coil array is an effective electromagnetic wave absorber in the sub-terahertz region, and it has two controllable electromagnetic absorption frequency bands.