Composite Electromagnetic Wave Absorber Made of Both Sendust and Aluminum Particles Dispersed in Polystyrene Resin
To design an electromagnetic wave absorber with good absorption properties at frequencies above 1 GHz, the frequency dependences of the relative complex permeability μr*, the relative complex permittivity εr*, and return loss were investigated for the composite made of both sendust (an alloy of Al 5%, Si 10%, and Fe 85%) and aluminum particles dispersed in polystyrene resin. It was found that the frequency dependence of μr* for this composite can be changed by adjusting the particle size of aluminum and the volume mixture ratio of sendust and aluminum. Therefore, a flexible design of an absorber with good absorption characteristics was proposed based on the ability to control μr*. The composite made of both sendust and aluminum was found to exhibit a return loss of less than −20 dB in the frequency range of not only several GHz but also around 20 GHz if appropriate volume mixture ratio and particle size were selected.
Shinobu Fujihara and Tadashi Takenaka
K. Sakai et al., "Composite Electromagnetic Wave Absorber Made of Both Sendust and Aluminum Particles Dispersed in Polystyrene Resin", Key Engineering Materials, Vol. 445, pp. 197-200, 2010