Complex permittivity and permeability of hexaferrite and carbonyl iron powders using rectangular waveguide technique from 8.0-40.0 GHz

Waveguide transmission-reflection technique is employed to determine the complex permittivity and permeability of hexaferrite powders and carbonyl iron powders in the microwave range from 8.0-40.0 GHz. It is shown that hexaferrite powders are very weak microwave dielectric and magnetic absorbers. Furthermore, both their dielectric and magnetic properties show little change in the investigated range. The carbonyl iron powders are all strong magnetic absorbers within the X-band range. However, the strength of their imaginary permeability dwindles rapidly by the time the KA-band is reached. Unlike hexaferrite powders, both the dielectric and magnetic properties of the carbonyl irons change considerably within the same frequency range.