Estimation of effective permittivity and effective thickness of inhomogeneous materials at 52-70 GHz

In this paper, a free-space method is used to measure the reflection coefficient of various materials in the 60 GHz band. This measurement method may be used to determine the effective permittivity and effective thickness of inhomogeneous materials. The materials of interest are carbon fiber reinforced plastic (CRP) and glass fiber reinforced plastic (GRP) as used in aircraft passenger cabins. Homogeneous materials like glass and acrylic glass are used to validate the method for the estimation of the effective permittivity and effective thickness.