| Abstract |
| Improvement in microwave absorbance has been investigated by insertion of a periodic air cavity in rubber composites filled with magnetic powders. A mixture of Co2Z hexagonal ferrite and Fe powders were used as the absorbent fillers in silicone rubber matrix. The complex permeability and complex permittivity of the magnetic composites were measured by reflection/transmission technique. In the grid-type magnetic absorbers, the equivalent permeability (εeq) and permittivity (εeq) are calculated as a function of air volume rate (K) on the basis of effective medium theory. Reduction in the material parameters (especially, dielectric permittivity and magnetic loss) has been estimated with the increase of K. Plotting the εeq and εeq on the solution map of wave-impedance matching, wide bandwidth microwave absorbance has been predicted in the magnetic composites with an optimum value of K. |
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| Key Words |
| composites, powder processing, magnetic properties, computer simulation, microwave absorbers |
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