ELECTROMAGNETIC WAVE ABSORBER USING COMPOSITES WITHGLASS FABRIC AND EPDXY

摘要

An electromagnetic wave (EM wave) absorber exhibitingover 10dB attenuation at 1.8GHz was fabricated. In thisresearch, glass-fabric/epoxy composites with various par-ticle additives were used in fabricating the absorber, andtheir abilities in EM wave absorption were compared. Theabsorber was made in square plate of many layers bystacking glass fabrics impregnated with epoxy and parti-cles. For a comparative study, conductive particles suchas CNT (Carbon Nano-tube), CNF (Carbon Nano-fiber)and CB (Carbon Black), and magnetic particles such asNi-Zn-ferrite were used. Each powder showed differentcharacteristics in EM wave absorption. For measuringabsorption ability, a system of repeater antenna and spec-trum analyzer was used in radiating and detecting the EMwave. Among various absorbers, the absorber using Ni-Zn-ferrite showed over 11dB attenuation and exhibitedoutstanding results. Although CNT or other particles werehighly conductive materials, the result showed lower at-tenuation than Ni-Zn-ferrite at 1.8GHz. For a microscopicobservation of Ni-Zn-ferrite, the SEM (Scanning ElectronMicroscope) was used which showed the structure ofglass fiber, epoxy and Ni-Zn-ferrite particles.