By combining rubber with carbon and ferrite in an appropriate weight ratio, the material which has both dielectric and magnetic losses, suitable for an electromagnetic-wave absorber, is obtained. The dispersion characteristics of complex relative permittivity and permeability of this material are measured, and equations of both permittivity and permeability are derived in RF frequencies. By using these dispersion equations, we can easily simulate applications using this kind of material as an electromagnetic wave absorvber.

The single layer absorber has the simplest structure among electromagnetic wave absorbers. To have thin and light materials with wide frequency characteristics for this structure, carbon and ferrite are mixed with rubber in different weight ratios. This new material has both dielectric and magnetic losses, which in a single layer structure, has good absorber characteristics . In the C-band, the relative bandwidth is up to 4.6 times wider, and the absorber is thinner, compared with nonmagnetic lossy dielectric material (i.e., 1.0, 0).

The shielding effect of a new material composed of rubber with carbon and ferrite for microwave oven leakage is investigated. By adding an appropriate amount of carbon, the shielding effect is improved. A large attenuation constant, which is 6 dB/cm larger than that of a rubber ferrite, is relizable.