THE MEASUREMENT CELL BASED ON THE QUARTZ QUAZIOPTICAL RESONATOR FOR RESEARCH ON DIELECTRIC LIQUIDS IN THE SUB-THZ RANGE

• Main Authors: A. A. Barannik, S. A. Vitusevich, А. I. Gubin, I. A. Protsenko, N. T. Cherpak
• Format: Article
• Language: English
• Published: Akademperiodyka 2016-06-01
• Series: Радиофизика и электроника
• Subjects: quartz quasioptical resonator; microfluidic channel; permittivity; bioliquids
• Online Access: http://re-journal.org.ua/sites/default/files/file_attach/2016-2/12.pdf
• ISSN: 1028-821X; 2415-3400

Using WGM resonators allow achieving high accuracy in determining the substances permittivities due to the high Q-factor. The resonator with a microfluidic channel is promising for the study of small-volume liquids, which is especially important for bioliquids. In a Ka-band a sapphire resonator with microfluidic channel has been proposed as a measurement cell, but in the sub-THz range a quartz resonator has more suitable characteristics due to its high Q-factor. In the paper we propose a measurement cell for the determination of complex permittivity of liquids in sub-THz range on the basis of quasi-optical quartz resonator with a layer of plastic comprising a microfluidic channel. Experimental studies of the resonator structure are carried out and a model for numerical research in the software COMSOL Multiphysics is proposed. By means of c omparing the resonator frequencies and Q-factors values with the corresponding values obtained with the numerical model the correction of the model has been carried out for the water-filled microfluidic channel. It is shown that the model for numerical studies correctly describes the resonator structure. The values of the resonator frequency and Q-factor obtained experimentally and numerically, for the microfluidic channel filled with the substances with well-known complex permittivity (methanol, propanol, ethanol, acetone), are in good agreement, which indicates the possibility of using the resonator as a measurement cell allowing the research on small-liquid permittivity using the special calibration procedure.