Wideband Characterization of Soil Complex Dielectric Permittivity Spectrum

We present a wideband characterization of soil complex dielectric permittivity spectra in the frequency range from 40 Hz to 500 MHz. Soil samples of various moisture content were measured with the use of a seven-rod probe, which was connected to an impedance analyzer and a vector-network-analyzer through a switch controlled by a PC. The use of a single probe in connection with both analyzers ensured that the same samples were examined in the whole frequency range, without the density changes nor significant moisture variations between the consecutive measurements by the analyzers. The spectra obtained from both instruments were merged and analyzed with the use of a combined permittivity and conductivity model.