Design and optimize spherical particle absorber by Fe-rich hollow cenosphere of fly-ash for broadband electromagnetic wave absorbing wall

Abstract

In this paper, the absorbing effectiveness of spherical particle absorber made of cheap Fe-rich hollow cenosphere fly-ash is analyzed. The effects of the diameter of spheres, the number of layer and the stack modes of sphere particle on the absorbing effectiveness were explored. Based on the results, a three-layer structure with mixed sizes of spheres was designed, constructed and tested. Obtained results show that this structure has a maximal reflection loss of 9 dB and the bandwidth being higher than 5 dB is more than 17 GHz. When applying the permittivity of Fe-rich hollow cenosphere fly-ash, and the thickness of absorber is 6.5 cm, the maximal reflection loss is 23 dB and the bandwidth being lower than −10 dB is more than 14 GHz, which covers the C, X and Ku bands. The experimental test proved that the three-layer structure absorber has good absorbing effectiveness.