Improvement of Absorbing Frequency Bandwidth of Composite Electromagnetic Wave Absorber Made of Granular Sendust Particles Dispersed in Polystyrene Resin

Composite electromagnetic wave absorber made of sendust dispersed in resin is low-cost and contains no rare metal. In this study, granular shaped sendust particles with the average particle size of approximately 5 and 20 mu m were dispersed in polystyrene resin with the volume ratio of 20-40 vol% in order to broaden the absorbing frequency bandwidth in the frequency range from above 10 GHz. Experimental results reveal that absorbing frequency bandwidth is drastically improved and the optimal volume mixture ratio of sendust is approximately 30 vol% for the average particle size of approximately 5 mu m and approximately 35 vol% for approximately 20 mu m.