Three-Dimensional Periodic Structured Absorber for Broadband Electromagnetic Radiation Absorption

Abstract

This study provides a novel broadband gypsum composite for electromagnetic (EM) radiation protection by the design of 3D circular periodic structure, and using carbon black (CB) as absorbent. The EM absorption performance was investigated by arch reflecting method in 2–18 GHz, and the obtained results indicate that the proposed gypsum absorber exhibits more than 90% absorption of EM radiation in the frequency range of 2–18 GHz. The EM wave absorption can be obviously affected by the variation of CB content, periodic cylinder height and diameter. The optimum CB content is 2 wt%, simultaneously, the absorption peak can be promoted to shift to lower frequency by the increase of periodic cylinder height and the increase of periodic cylinder diameter is beneficial to widen the effective bandwidth. The λ/4 interference of reflected waves, energy dissipation of CB particles, and multi-reflection, resonance, edge diffractions, and impedance matching caused by 3D periodic structural design work synergistically to achieve the high EM absorption efficiency and wide frequency band. It is expected that the proposed 3D circular periodic structured gypsum absorber has great potential in indoor EM radiation prevent.