Complementary frequency selective surfaces for waveguide dielectric measurements

The use of dielectric materials is a popular method to decrease the antenna size. Accurate knowledge of the permittivity and losses of the materials is essential to understand and optimize antenna design. Various methods of measuring the dielectric properties exist including the use of waveguides, resonators and plane wave excitations. They all have advantages and disadvantages. Complex or heterogeneous materials are inherently difficult to measure. The authors have previously addressed the idea of creating artificial dielectrics using small scale metallic inclusions embedded in a host medium [Njoku et al. IEEE TAP, Vol. 60, No. 5, pp. 2194-2202, 2012]. This work may well be beneficial for characterizing such mixtures.