On the design and characterisation of a microwave microstrip resonator for gas sensing applications

Abstract

This study focuses on the microwave characterisation of a microstrip resonator aimed for gas sensing applications. The developed one-port microstrip resonator, consisting of three concentric rings with a central disk, is coupled to a 50-Ohm microstrip feedline through a small gap. A humidity sensing layer is deposited on this gap by drop-coating an aqueous solution of Ag@alpha-Fe<sub>2</sub>O<sub>3</sub> nanocomposite. The operation principle of the developed humidity sensor is based on the change of the dielectric properties of the Ag@alpha-Fe<sub>2</sub>O<sub>3</sub> nanocomposite when the relative humidity is varied. However, it should be underlined that, depending on the choice of the sensing material, different target gases of interest can be detected with the proposed structure. The frequency-dependent response of the sensor is obtained using the reflection coefficient measured from 3.5 GHz to 5.6 GHz with relative humidity ranging from 0 %rh to 83 %rh. The variation of the humidity concentration strongly impacts on the two resonances detected in the measured reflection coefficient. In particular, an increase of the humidity level leads to lowering both resonant frequencies, which can be used as sensing parameters for humidity monitoring purpose. An exponential function has been used to accurately model the two resonant frequencies as a function of the humidity.

Development, Characterization, and Circuit Modeling of Inkjet-Printed Coupled Ring Resonators for Application in Biological Samples

“…This can be exploited for sensor development. In a planar microwave resonant sensor, a change in the dielectric properties of a surrounding material is transduced into an alteration in the electric field that results in a change in the resonant frequency [34], [35], [36], [37].…”

“…onto a rigid or flexible substrate [1]. This technology has been successfully used with a variety of substrates (e.g., paper, polyimide, polyethylene terephthalate, plastic, fiberglass, and ceramic) and different types of inks, including polymer, metal, and carbon [2], [3], [4]. Because of its many interesting qualities and high applicability for adoption in a wide range of applications, IJP stands out among the other competing technologies.…”

A Principal Componet Analysis to detect cancer cell line aggressiveness

“…Indeed, this technology has consolidated its use in various fields. For example, Gugliandolo et al [10] developed a microwave microstrip resonator to measure water vapor for industrial pipeline applications. Likewise, Majcher et al [11] investigated the possibility of using a dagger-shaped probe to measure soil moisture in agrifood applications.…”

Measurement of low‐loss aqueous solutions permittivity with high detection accuracy by a contact and free‐label resonance microwave sensor

“…Different methods of design in the resonance style depend on whether the sample type is solid, 26–29 liquid, 30–37 or gas 38 . Gas sensors are able to detect their presence and type, and they are very useful in industries 39,40 . The various methods used in the papers include rat race coupled, 41 parallel coupled, 42 phase variation, 43 near‐field self‐injection‐locked and spiral bandgap, 44 GaAs monolithic microwave integrated circuit, 45 coplanar waveguide‐fed wearable antenna, 46 ring loaded monopole antenna, 47 wireless networks, 48,49 and split‐ring resonators (SRR) 50–52 .…”

“…38 Gas sensors are able to detect their presence and type, and they are very useful in industries. 39,40 The various methods used in the papers include rat race coupled, 41 parallel coupled, 42 phase variation, 43 near-field self-injection-locked and spiral bandgap, 44 GaAs monolithic microwave integrated circuit, 45 coplanar waveguide-fed wearable antenna, 46 ring loaded monopole antenna, 47 wireless networks, 48,49 and split-ring resonators (SRR). [50][51][52] In Ebrahimi et al, 53 the dielectric properties of the samples are determined using a complementary SRR (CSRR) structure.…”