Broadband dielectric characterization of aqueous saline solutions by an interferometer-based microwave microscope
Résumé
The complex dielectric permittivity of aqueous saline solutions has been determined in the frequency range [2-18 GHz] with a home-made near-field microwave microscope. The instrument is built on a vector network analyzer, a matching network, and an evanescent microwave probe. The interferometer-based matching network enables highly reproducible, sensitive, and accurate measurements on the entire frequency band of operation. NaCl solutions concentrations ranging from 0 to 160 mg/ml are investigated at 25 °C. A maximum measurement sensitivity for NaCl concentrations is found to be equal to 2.3 dB/(mg/ml) and 7.7°/(mg/ml) for magnitude and phase-shift, respectively. To translate the measurement data (S parameters) to the corresponding complex permittivities, an inversion procedure based on a simple calibration model is applied. The resulting complex permittivities are found to be in a very good agreement with those calculated by Cole-Cole model. © 2016 Author(s).
Mots clés
Complex networks
Electric network analyzers
Interferometers
Scattering parameters
Sodium chloride
Accurate measurement
Complex dielectric permittivities
Dielectric characterization
Evanescent microwave probes
Measurement sensitivity
Microwave microscopes
Near-field microwave microscopes
Vector network analyzers
Permittivity
Domaines
Sciences de l'ingénieur [physics]Origine | Fichiers éditeurs autorisés sur une archive ouverte |
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