Test Stand for Measuring the Free-Space Electromagnetic Parameters of Materials over an Ultrawide Range of Microwave Frequencies

Abstract

A special system has been developed for measurement in free space of the following parameters of flat material samples: reflection and transmission coefficients, permittivity and permeability, angular dependence of the transmission coefficient, and temperature dependence of the reflection coefficient of rf absorbing coatings on metal substrates for normal incidence of electromagnetic waves at frequencies of 1–40 GHz. In order to increase the accuracy of the measurements various digital signal processing algorithms are proposed, including a way of suppressing the Gibbs phenomenon at the edges of the frequency band, as well as a method for correcting the results of S-parameter measurements during determinations of the permittivity and permeability of small samples.