The Relationship of Permeability and Permittivity at the Perfect Matching Point of Electromagnetic Wave Absorption for the Absorber Filled by Metallic Magnetic Particles

The electromagnetic wave absorption properties of flake-shaped carbonyl-iron/paraffin composites with various volume concentrations were calculated by the measured complex permeability and permittivity. The complete electromagnetic wave absorption was searched for the volume concentration of 0.125, 0.15 and 0.20 at 5.8, 4, and 3.6 GHz, respectively. The permittivity is much larger than the permeability at the complete absorption frequency points. Based on the origin of the absorbing peaks, the contour map displaying the relationship between the complex permittivity and complex permeability at the perfect matching point was developed. The complex permittivity obtained from the contour map basically agrees with the experimental data for a given complex permeability. Hence, the contour map can be used to design the absorber for obtaining the excellent electromagnetic wave absorption.