Evaluation of Composite Electromagnetic Wave Absorber made of Polystyrene Resin and Permalloy or Sendust
The frequency dependences of the complex permeability μ r*, complex permittivity ε r*, and return loss were investigated for composite electromagnetic wave absorbers made of soft magnetic materials (permalloy or sendust) and polystyrene resin. For permalloy, two types of particle shape were used: grain-type or flake-type. The volume mixture ratio of magnetic materials was varied in the range from 40 % to 70 %. The values of the real part μ ’ and imaginary part μ ” of μ r * increased with increasing mixture ratio of magnetic materials. The frequency dependence of μ r * for flake-type permalloy composite was similar to that for sendust composite. All absorbers showed the absorption of electromagnetic waves in the frequency range above 1 GHz.
K. Katayama, K. Kato, T. Takenaka, M. Takata and K. Shinozaki
K. Sakai and S. Yoshikado, "Evaluation of Composite Electromagnetic Wave Absorber made of Polystyrene Resin and Permalloy or Sendust", Key Engineering Materials, Vol. 350, pp. 239-242, 2007