Microstrip Line loaded with Series Gap and Dumbbell Defect-Ground-Structure (DB-DGS) Resonator for Highly Sensitive Sensing Based on Resonance/Antiresonance : Application to Humidity Measurements
Kurniawati, Nazmia (Universitat Autònoma de Barcelona. Departament d'Enginyeria Electrònica)
Vélez Rasero, Paris (Universitat Autònoma de Barcelona. Departament d'Enginyeria Electrònica)
Casacuberta Orta, Pau (Universitat Autònoma de Barcelona. Departament d'Enginyeria Electrònica)
Su, Lijuan (Universitat Autònoma de Barcelona. Departament d'Enginyeria Electrònica)
Canalias, Xavier (Universitat Autònoma de Barcelona. Departament d'Enginyeria Electrònica)
Martín, Ferran (Universitat Autònoma de Barcelona. Departament d'Enginyeria Electrònica)

Date:	2025
Abstract:	A new planar structure for the implementation of highly sensitive single-frequency microwave sensors is proposed. The key aspect to obtaining high sensitivity is to generate closely spaced resonance and antiresonance frequencies, achieved by means of a microstrip line with a series gap etched on top of a transversely oriented dumbbell defect-ground-structure (DB-DGS) resonator, the sensitive element. By this means, both the magnitude and the phase of the transmission coefficient exhibit a high phase slope between such frequencies. The result is a high sensitivity of either the magnitude or the phase of the transmission coefficient at the operating frequency with the dielectric constant of the environment surrounding the DB-DGS resonator. Advantages of the proposed device are (i) size and simplicity and (ii) isolation between the analyte (or material under test -MUT) and the line strip. Two sensors with different DB-DGS geometry are reported to validate the proposed approach. Using the phase as the main output variable, the maximum sensitivity in one of the prototypes is found to be 88. 7° per unit of dielectric constant variation. This sensor has been applied to relative humidity (RH) measurements by using a functional film of polyvinyl alcohol (PVA) deposited on top of the sensing DB-DGS resonator. The average sensitivity in this case is 0. 33°/% (note that RH is given in %).
Grants:	Agencia Estatal de Investigación PID2022-139181OB-I00 Agencia Estatal de Investigación CPP2021-009080 Agència de Gestió d'Ajuts Universitaris i de Recerca 2021/SGR-00192 Agència de Gestió d'Ajuts Universitaris i de Recerca 2024/ICREA-00114 Ministerio de Ciencia e Innovación RYC2022-035819-I Agencia Estatal de Investigación FPU20/05700 Agencia Estatal de Investigación PREP2022-000364
Note:	Altres ajuts: acords transformatius de la UAB
Rights:	Aquest document està subjecte a una llicència d'ús Creative Commons. Es permet la reproducció total o parcial, la distribució, la comunicació pública de l'obra i la creació d'obres derivades, fins i tot amb finalitats comercials, sempre i quan es reconegui l'autoria de l'obra original.
Language:	Anglès
Document:	Article ; recerca ; Versió publicada
Published in:	IEEE sensors letters, Vol. 9, Issue 6 (May 2025) , art. 3501804, ISSN 2475-1472

DOI: 10.1109/LSENS.2025.3567134

4 p, 1.5 MB

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Research literature > UAB research groups literature > Research Centres and Groups (research output) > Engineering > CIMITEC-UAB
Articles > Research articles
Articles > Published articles