Abstract
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.
Additional information
Notes on contributors
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Koyu Chinen
Koyu Chinen received the MSc and PhD degrees in electronics engineering from Shizuoka University in 1978 and 1981, respectively. In 1981 he was with Toshiba corporation working on developing optical electronics devices for high-speed optical fiber communications from 1981 to 2004. In 2005, he joined the National Institute of Technology Okinawa College, as a professor of Information Communication System Eng. In 2017, he was an emeritus professor and representative of GLEX. His main research interests include RF design in optical wireless communication and bio-electronics. Corresponding author. Email: [email protected]
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Shoko Nakamoto
Shoko Nakamoto received the BEng degree from the Information Communication System Eng Dept of National Institute of Technology, Okinawa College in 2014. Since then, she has technically supported the GLEX. Her main interests include RF design and bio-electronics. Email: [email protected]
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Ichiko Kinjo
Ichiko Kinjo received her PhD degree from Hokkaido University in 2005. In 2005, she joined the Information Communication System Eng Dept of National Institute of Technology, Okinawa College, as an assistant professor and was a professor in 2020. Her main interests include OR and information communication technologies. Email: [email protected]