Composites Based on Rice Husk Ash/Polyester for Use as Microwave Absorber

This paper is to study the dielectric properties and microwave absorption of rice husk ash/polyester (RHAP) composites. The RHAP composites prepared with different weight ratio (40–80 wt. %) of rice husk ash (RHA) loading into polyester was fabricated. A rectangular waveguide transmission line method was used to measure the dielectric properties of the RHAP composites. The RHAP samples were designed and simulated with different thickness and percentage of RHA loading by using Computer Simulation Technology Microwave Studio (CST-MWS) software. The materials, their dielectrics properties measurement and microwave absorption result over 12.4–18 GHz (Ku-Band) frequency range are discussed. The dielectric properties of composites increase with increasing loading the RA wt%. The RHAP sample with different thickness was investigated in Ku-Band. The microwave absorption was up to 99.84 %, using 80 % loading of RHA with thickness 15 mm at 13.81 GHz, and showing the RHAP composites is applicable as microwave absorber.