Effect of Particle Shape on Absorption Characteristics of Composite Electromagnetic Wave Absorber Made of Sendust Particles Dispersed in Polystyren Resin

The frequency dependences of the relative complex permeability μr* the relative complex permittivity εr* and the return loss for the composite made of sendust flakes or spherical sendust particles dispersed in polystyrene resin were investigated in the frequency range from 1 to 40 GHz. The values of εr* increased when sendust flakes were dispersed in polystyrene resin and the frequency dependence of μr* was different in the particles shape of sendust. Therefore, absorption characteristics depended on the particle shape of sendust and the absorption of electromagnetic waves with a wide bandwidth in the frequency range from 10 and 20 GHz could be achieved using spherical sendust particle with a low volume mixture ratio.