Fast Readout of Split-Ring Resonators Made Simple and Low-Cost for Application in HPLC

verfasst von
Moritz Hitzemann, Kirsten J. Dehning, Adrian V. Gehl, Erk Fietje Sterr, Stefan Zimmermann
Abstract

Split-ring resonators (SRR) are simple electrical circuits that show a significant shift in resonance frequency even with the smallest changes in split capacitance, and thus in permittivity, electric conductivity, and dielectric losses of the split capacitor’s dielectric. Usually, the resonance frequency is derived from the frequency response, but recording the frequency spectrum takes a certain amount of time. Here, we present a new capillary split-ring resonator CaSRR with fast readout for liquid chromatography (LC), which is capable of accurately detecting very fast changes in split capacity. The proposed method is based on the detection of the transmitted signal at a single frequency that is analyzed by demodulation. The demodulated signal changes its amplitude depending on the shift of the resonance frequency. Our simple low-cost electronics enables an average sampling rate of 42 Hz with 128 averages of the demodulated signal and has a frequency stability of 840 mHz. Thus, a minimum change in permittivity of ∆εr,min = 11.26 × 10−3 can be detected. Finally, a chromatogram of one sugar (glucose) and one sugar alcohol (xylitol) is recorded using the SRR and is compared to a standard refractive index detector.

Organisationseinheit(en)
Fachgebiet Sensorik und Messtechnik
Fachgebiet Mixed-Signal-Schaltungen
Typ
Artikel
Journal
Electronics (Switzerland)
Band
11
Anzahl der Seiten
14
ISSN
2079-9292
Publikationsdatum
04.04.2022
Publikationsstatus
Veröffentlicht
Peer-reviewed
Ja
ASJC Scopus Sachgebiete
Steuerungs- und Systemtechnik, Signalverarbeitung, Hardware und Architektur, Computernetzwerke und -kommunikation, Elektrotechnik und Elektronik
Elektronische Version(en)
https://doi.org/10.3390/electronics11071139 (Zugang: Offen)