Measurement of complex permittivity of composite materials using waveguide method

Complex dielectric permittivity of 4 different composite materials has been measured using the transmission line method. A waveguide fixture in L, S, C and X band was used for the measurements. Measurement accuracy is influenced by air gaps between test fixtures and the materials tested. One of the materials, unprotected glass fiber composite, has directional effects. All materials tested show low permittivity.