Electromagnetic wave absorber and a process of producing same

摘要

An electromagnetic wave absorber having an excellent electromagnetic wave absorption characteristic in 5 to 6 GHz band. The electromagnetic wave absorber has a matrix and powder filled in the matrix. The particles of the powder have electrical conductivity at least in surface regions thereof and have a particle diameter of 3 to 20 µm as expressed by D 50 value. A volumetric ratio (V) in which the powder is filled in the matrix is set such that a standardized value expressed as a value obtained by dividing a complex relative permeability (µ") of the electromagnetic wave absorber in a frequency band to be absorbed thereby by the volumetric ratio (V) is constant as far as the particle diameter of the powder used, as expressed by the D 50 value, is within the range of 3 to 20 µm.