Three-dimensional hexagonal periodic structured absorber for broadband electromagnetic wave absorption

A broadband three-dimensional (3D) hexagonal periodic structured gypsum absorber incorporated with carbon black (CB) was designed and fabricated, and the effects of geometric parameters and CB mass fraction on the electromagnetic (EM) wave absorption performance were simulated and measured in 2–18 GHz. The simulation and experimental results exhibit that the effective bandwidth for reflection loss (RL) under –  10 dB can cover the whole frequency ranges of 2–18 GHz. The appreciable agreement between simulation and experiments testifies the validity of the well-designed gypsum absorber. The broadband absorption performance can be attributed to the synergistic effect of structural design and material characteristics. The impedance matching condition can be significantly improved due to the periodic structural design, and most incident EM waves can be attenuated by the multiple reflections and diffractions effects induced by 3D periodic hexagonal arrays and eddy current loss, conductivity loss and dielectric polarization loss caused by CB particles. It is believed that the proposed 3D periodic hexagonal structured gypsum absorber has great potentials in military and civilian applications to avoid radar detection and solve EM radiation pollution.