Microwave Interferometry Based On Open-ended Coaxial Technique  for High Sensitivity Liquid Sensing

Bakli, Hind; Haddadi, Kamel

doi:10.7716/aem.v6i3.428

Cited by 6 publications

(5 citation statements)

References 7 publications

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“…Complex dielectric properties of brain tissues were studied for RF and microwave frequency in [11]. Bakli and Haddadi [12] introduced a modified openended coaxial probe for high sensitivity solution sensing at microwave frequency. A comprehensive description about the interaction of electromagnetic waves (from RF to microwave) with biological tissues for the purpose of characterization was reviewed in [13].…”

Section: Introductionmentioning

confidence: 99%

Microwave Characterization of Hydrophilic and Hydrophobic Plant Pathogenic Fungi Using Open-Ended Coaxial Probe

et al. 2019

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Plant diseases have a direct impact on agricultural food production. The time required to detect the pathogen plays a crucial role to minimize the fungal-induced disease damage in crops. Current microbial detection techniques take several days to identify the disease. Microwave detection techniques have proven to be a good candidate in identifying pathogens. Microwave dielectric characterization based on an open-ended coax technique is proposed to electrically characterize pathogens having potential applications in plant diseases. Seven common fungi growing on major crops in the United Arab Emirates were isolated and cultured in the lab. A microwave dielectric assessment kit, based on the open-ended coax technology, was used to obtain the dielectric properties of samples. Our data demonstrated a distinct variability between soil-and airborne pathogenic fungi. Thus, individual fungi can be identified based on their specific microwave dielectric signature. Factors such as conidial sporulation and hyphal growth and polarization of these fungi may attribute to these electric discrepancies. Dielectric spectroscopy modeling based on the Havriliak-Negami model was used to help to understand the molecular structure interaction with the high-frequency signal. This paper revealed a significant dielectric contrast behavior variation among all seven fungi. This paper also supported previous results obtained by other researchers, which classified fungi into two main groups, namely hydrophilic and hydrophobic. Nonetheless, the fungus Alternaria solani has different behavior from this classification. This research is the first to demonstrate the ability of dielectric microwave characterizations tests to facilitate rapid diagnosis and appropriate treatments of plant diseases. INDEX TERMS Dielectric spectroscopy, fungi, microwave characterization, open-ended coaxial probe, plant pathology.

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Section: Introductionmentioning

confidence: 99%

Microwave Characterization of Hydrophilic and Hydrophobic Plant Pathogenic Fungi Using Open-Ended Coaxial Probe

et al. 2019

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“…Microwave characterization is commonly classified into two categories. On the one hand, we find broadband techniques, including free-space [1][2][3], guided (including on-wafer) [4] and open-ended coaxial probing [5][6][7] methods, which have the ability to characterize materials with medium to high loss on a broad frequency range. On the other hand, we find narrowband techniques mostly based on resonant structures to achieve accurate measurements of the dielectric properties of low-loss materials [8].…”

Section: Introductionmentioning

confidence: 99%

Near-Field Scanning Millimeter-Wave Microscope Operating Inside a Scanning Electron Microscope: Towards Quantitative Electrical Nanocharacterization

et al. 2021

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The main objectives of this work are the development of fundamental extensions to existing scanning microwave microscopy (SMM) technology to achieve quantitative complex impedance measurements at the nanoscale. We developed a SMM operating up to 67 GHz inside a scanning electron microscope, providing unique advantages to tackle issues commonly found in open-air SMMs. Operating in the millimeter-wave frequency range induces high collimation of the evanescent electrical fields in the vicinity of the probe apex, resulting in high spatial resolution and enhanced sensitivity. Operating in a vacuum allows for eliminating the water meniscus on the tip apex, which remains a critical issue to address modeling and quantitative analysis at the nanoscale. In addition, a microstrip probing structure was developed to ensure a transverse electromagnetic mode as close as possible to the tip apex, drastically reducing radiation effects and parasitic apex-to-ground capacitances with available SMM probes. As a demonstration, we describe a standard operating procedure for instrumentation configuration, measurements and data analysis. Measurement performance is exemplarily shown on a staircase microcapacitor sample at 30 GHz.

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“…Dielectric spectroscopy is a method well suited to characterize mixtures of water and other substances. The open-ended coaxial probe [1,2,3,4,5,6,7,8,9,10] is suited for non-intrusive permittivity measurements of fluids flowing in pipelines as the sensor can be placed flush with the inner pipe wall and thereby not disturb the flow. In many applications, the material to be characterized has a limited thickness [9,10].…”

Section: Introductionmentioning

confidence: 99%

Combined Thickness and Permittivity Measurement of Thin Layers with Open-Ended Coaxial Probes

Folgerø

Haukalid

Kocbach

et al. 2019

Sensors

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This paper presents a method to simultaneously determine the thickness and permittivity of thin layers from multi-frequency reflection coefficient measurements using an open-ended coaxial probe. This is achieved by exploiting that the probe becomes radiating at frequencies higher than the probe’s typical operating range. Permittivity information is extracted from measurements in the typical frequency range, whereas thickness information is obtained from high frequency measurements by exploiting resonances that occur when the radiated waves are reflected at the layer boundary. A finite element model of the measurement set-up is made in COMSOL MultiphysicsTM, and a matrix of simulations spanning the relevant layer thicknesses and permittivity range is generated. The measured permittivity spectra of unknown samples are compared to the simulation matrix to estimate layer thickness and permittivity. The method is verified by measurements of water–ethanol mixtures. An application example where the water fraction and layer thickness of a gas hydrate deposition layer is estimated from permittivity measurements in a multiphase flow loop is also presented.

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Microwave Interferometry Based On Open-ended Coaxial Technique for High Sensitivity Liquid Sensing

Cited by 6 publications

References 7 publications

Microwave Characterization of Hydrophilic and Hydrophobic Plant Pathogenic Fungi Using Open-Ended Coaxial Probe

Microwave Characterization of Hydrophilic and Hydrophobic Plant Pathogenic Fungi Using Open-Ended Coaxial Probe

Near-Field Scanning Millimeter-Wave Microscope Operating Inside a Scanning Electron Microscope: Towards Quantitative Electrical Nanocharacterization

Combined Thickness and Permittivity Measurement of Thin Layers with Open-Ended Coaxial Probes

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