The chiral materials were prepared by using the carbon fiber helices as chiral inclusions, and the composite of Fe3O4 and polyaniline as matrix. The electromagnetic properties, including the rotation angles, the axial ratios and the complex chirality parameters, were measured by using a circular waveguide method in the 8.5-11.0 GHz frequency range. The dependence of these electromagnetic properties on the frequency and the concentration of the Fe3O4 in the composite matrix were analyzed. The results show that an appropriate concentration of Fe 3O4 in the matrix is useful in improving the elect...
