Microwave Absorption Properties of Cement Composites Containing Carbon fibers and Ferrites

摘要

W-type BaCo2Fe16O27 hexaferrite which was prepared by sol-gel method and short carbon fibers were filled into cement composites in order to study the microwave absorption properties of the cement composites. Complex permittivity and permeability of the cement composites filled with ferrites and short carbon fibers were measured at Ku waveband (12.4～ 18.0 GHz), and their reflectivity was calculated according to the measured electromagnetic parameters. The results of prediction show that the carbon fibers play a key role in improving absorption properties of cement composites. The absorption properties of cement composites filled with 0.2％ of short carbon fibers and 35％ of ferrite by weight are excellent. The absorption bandwidth less than -10 dB of the cement composite of thickness d=1.5mm reached 4.4 GHz, and peak value is -27.0 dB at about 15.8 GHz.