Application of free-space transmission technique for shielding effectiveness measurement of special materials at 2,5–5 GHz

In this paper, we present results of measurement S₂₁ parameter for two special shielding materials in the 2,5-5 GHz frequency band. Measurements were carried out using well-known free-space transmission technique. Experimental set-up has been modified by adding an absorbing frame to reduce resonant and diffraction effects at specimen edges. Shielding effectiveness (SE) of two test materials depending on electromagnetic (EM) wave polarization and distance between a material under test and an antenna are presented.