Method of retrieving permittivity from S12 element of the waveguide scattering matrix

In this paper, a numerical method of retrieving the complex dielectric permittivity from the S
₁₂
element of the waveguide scattering matrix. Analysis showed that the numerical method proposed provides for the permittivity which has the error less than 10% in the frequency range from 0.345 to 15 GHz. This error is substantially less than the one attained in the existing method currently used.