Signal-to-Noise Ratio Analysis for the Voltage-Mode Read-Out of Quartz Tuning Forks in QEPAS Applications
Quartz tuning forks (QTFs) are employed as sensitive elements for gas sensing applications implementing quartz-enhanced photoacoustic spectroscopy. Therefore, proper design of the QTF read-out electronics is required to optimize the signal-to-noise ratio (SNR), and in turn, the minimum detection lim...
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| Format: | Article |
| Language: | English |
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MDPI AG
2023-03-01
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| Series: | Micromachines |
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| Online Access: | https://www.mdpi.com/2072-666X/14/3/619 |
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| author | Michele Di Gioia Luigi Lombardi Cristoforo Marzocca Gianvito Matarrese Giansergio Menduni Pietro Patimisco Vincenzo Spagnolo |
| author_facet | Michele Di Gioia Luigi Lombardi Cristoforo Marzocca Gianvito Matarrese Giansergio Menduni Pietro Patimisco Vincenzo Spagnolo |
| author_sort | Michele Di Gioia |
| collection | DOAJ |
| description | Quartz tuning forks (QTFs) are employed as sensitive elements for gas sensing applications implementing quartz-enhanced photoacoustic spectroscopy. Therefore, proper design of the QTF read-out electronics is required to optimize the signal-to-noise ratio (SNR), and in turn, the minimum detection limit of the gas concentration. In this work, we present a theoretical study of the SNR trend in a voltage-mode read-out of QTFs, mainly focusing on the effects of (i) the noise contributions of both the QTF-equivalent resistor and the input bias resistor R<sub>L</sub> of the preamplifier, (ii) the operating frequency, and (iii) the bandwidth (BW) of the lock-in amplifier low-pass filter. A MATLAB model for the main noise contributions was retrieved and then validated by means of SPICE simulations. When the bandwidth of the lock-in filter is sufficiently narrow (BW = 0.5 Hz), the SNR values do not strongly depend on both the operating frequency and R<sub>L</sub> values. On the other hand, when a wider low-pass filter bandwidth is employed (BW = 5 Hz), a sharp SNR peak close to the QTF parallel-resonant frequency is found for large values of R<sub>L</sub> (R<sub>L</sub> > 2 MΩ), whereas for small values of R<sub>L</sub> (R<sub>L</sub> < 2 MΩ), the SNR exhibits a peak around the QTF series-resonant frequency. |
| first_indexed | 2024-03-11T06:09:43Z |
| format | Article |
| id | doaj.art-d39fa799e0cf4e84b9bd3522fb386540 |
| institution | Directory Open Access Journal |
| issn | 2072-666X |
| language | English |
| last_indexed | 2024-03-11T06:09:43Z |
| publishDate | 2023-03-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Micromachines |
| spelling | doaj.art-d39fa799e0cf4e84b9bd3522fb3865402023-11-17T12:43:19ZengMDPI AGMicromachines2072-666X2023-03-0114361910.3390/mi14030619Signal-to-Noise Ratio Analysis for the Voltage-Mode Read-Out of Quartz Tuning Forks in QEPAS ApplicationsMichele Di Gioia0Luigi Lombardi1Cristoforo Marzocca2Gianvito Matarrese3Giansergio Menduni4Pietro Patimisco5Vincenzo Spagnolo6PolySense Lab, Dipartimento Interateneo di Fisica, University and Politecnico of Bari, Via Amendola 173, 70126 Bari, ItalyDipartimento di Ingegneria Elettrica e Dell’Informazione, Politecnico of Bari, Via Edoardo Orabona 4, 70126 Bari, ItalyDipartimento di Ingegneria Elettrica e Dell’Informazione, Politecnico of Bari, Via Edoardo Orabona 4, 70126 Bari, ItalyDipartimento di Ingegneria Elettrica e Dell’Informazione, Politecnico of Bari, Via Edoardo Orabona 4, 70126 Bari, ItalyPolySense Lab, Dipartimento Interateneo di Fisica, University and Politecnico of Bari, Via Amendola 173, 70126 Bari, ItalyPolySense Lab, Dipartimento Interateneo di Fisica, University and Politecnico of Bari, Via Amendola 173, 70126 Bari, ItalyPolySense Lab, Dipartimento Interateneo di Fisica, University and Politecnico of Bari, Via Amendola 173, 70126 Bari, ItalyQuartz tuning forks (QTFs) are employed as sensitive elements for gas sensing applications implementing quartz-enhanced photoacoustic spectroscopy. Therefore, proper design of the QTF read-out electronics is required to optimize the signal-to-noise ratio (SNR), and in turn, the minimum detection limit of the gas concentration. In this work, we present a theoretical study of the SNR trend in a voltage-mode read-out of QTFs, mainly focusing on the effects of (i) the noise contributions of both the QTF-equivalent resistor and the input bias resistor R<sub>L</sub> of the preamplifier, (ii) the operating frequency, and (iii) the bandwidth (BW) of the lock-in amplifier low-pass filter. A MATLAB model for the main noise contributions was retrieved and then validated by means of SPICE simulations. When the bandwidth of the lock-in filter is sufficiently narrow (BW = 0.5 Hz), the SNR values do not strongly depend on both the operating frequency and R<sub>L</sub> values. On the other hand, when a wider low-pass filter bandwidth is employed (BW = 5 Hz), a sharp SNR peak close to the QTF parallel-resonant frequency is found for large values of R<sub>L</sub> (R<sub>L</sub> > 2 MΩ), whereas for small values of R<sub>L</sub> (R<sub>L</sub> < 2 MΩ), the SNR exhibits a peak around the QTF series-resonant frequency.https://www.mdpi.com/2072-666X/14/3/619quartz-enhanced photoacoustic spectroscopyquartz tuning forkvoltage-mode read-outfront-end electronicssignal-to-noise ratiogas sensing |
| spellingShingle | Michele Di Gioia Luigi Lombardi Cristoforo Marzocca Gianvito Matarrese Giansergio Menduni Pietro Patimisco Vincenzo Spagnolo Signal-to-Noise Ratio Analysis for the Voltage-Mode Read-Out of Quartz Tuning Forks in QEPAS Applications Micromachines quartz-enhanced photoacoustic spectroscopy quartz tuning fork voltage-mode read-out front-end electronics signal-to-noise ratio gas sensing |
| title | Signal-to-Noise Ratio Analysis for the Voltage-Mode Read-Out of Quartz Tuning Forks in QEPAS Applications |
| title_full | Signal-to-Noise Ratio Analysis for the Voltage-Mode Read-Out of Quartz Tuning Forks in QEPAS Applications |
| title_fullStr | Signal-to-Noise Ratio Analysis for the Voltage-Mode Read-Out of Quartz Tuning Forks in QEPAS Applications |
| title_full_unstemmed | Signal-to-Noise Ratio Analysis for the Voltage-Mode Read-Out of Quartz Tuning Forks in QEPAS Applications |
| title_short | Signal-to-Noise Ratio Analysis for the Voltage-Mode Read-Out of Quartz Tuning Forks in QEPAS Applications |
| title_sort | signal to noise ratio analysis for the voltage mode read out of quartz tuning forks in qepas applications |
| topic | quartz-enhanced photoacoustic spectroscopy quartz tuning fork voltage-mode read-out front-end electronics signal-to-noise ratio gas sensing |
| url | https://www.mdpi.com/2072-666X/14/3/619 |
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