Analysis of Properties of Flake Sendust EM Wave Absorber according to Granularity

In this paper, we analyzed the characteristics of the EM wave absorber which was fabricated by using flake sendust (soft metal magnetic powder). The flake sendust was made of 3 different granularity by attrition mill. First, we have fabricated 3 kind of EM wave absorbers using the flake sendust and CPE(Chlorinated Polyethylene) and measured the S-parameters of the EM wave absorber. The complex relative permittivity and permeability were calculated from the measured data and the variations according to a change of granularity were researched. As a result, it was confirmed that the EM wave absorber using flake sendust with the average granularity has outstanding absorption ability in high frequency range(C band) for the reduction of eddy current loss(increase of permeability) and the increase of space charge polarization(increase of permittivity).