(searched for: doi:10.29252/ijmt.12.25)
IETE Journal of Research pp 1-9; https://doi.org/10.1080/03772063.2022.2081264
We deduced two-port equivalent circuits related to molar concentrations M (0–1 mol/L) of NaCl solutions by measuring S-parameters S11 and S21 at frequencies from 1 to 100 MHz, using a portable vector-network-analyzer (NanoVNA) and two-port coaxial probes. The deduced two-port equivalent circuits of the NaCl solutions consist of three sub-CR circuits. Resistances Rn and capacitances Cn comprising the sub-CR circuits were calculated using the molar concentrations M related to solute-ions of Na+ and Cl− and relative dielectric constant of solvent H2O. The electrical conductivity of the two-port equivalent circuits reflected drift mobility of the solute ions and rotation and vibration of polar molecules of the solvent H2O. Input impedances Zin and transmission coefficients S21 calculated from the deduced two-port equivalent circuits of the NaCl solutions were consistent with the measured S-parameters.