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    Broadband Soil Permittivity Measurements Using a Novel De-Embedding Line-Line Method
    (IEEE-Inst Electrical Electronics Engineers Inc, 2022) Hasar, Hafize; Hasar, Ugur C.; Kaya, Yunus; Oztas, Taskin; Canbolat, Mustafa Y.; Aslan, Nevzat; Ertugrul, Mehmet
    A new de-embedding line-line method has been proposed for accurate complex relative permittivity (epsilon(r)) determination of soil samples loaded into an EIA 1-5/8 '' coaxial transmission line measurement system. The method has three main features. First, it bypasses the requirement of calibration of this system by using only two identical coaxial lines with different lengths. Second, it does not need any numerical technique for epsilon(r) determination. Third, it does not require knowledge of electromagnetic properties and thickness information of the bead used for supporting soil samples. The method is next validated by simulations performed using a full 3-D electromagnetic simulation program (CST Microwave Studio) and by epsilon(r) measurement of a polyethylene (PE) material. Finally, epsilon(r) values of three air-dried and water-saturated soil samples having 90% or more sand content with different electrical conductivities (ECs) and gathered from different areas of the city Gaziantep in Turkey, were measured.
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    Honey-Water Content Analysis by Mixing Models Using a Self-Calibrating Microwave Method
    (IEEE-Inst Electrical Electronics Engineers Inc, 2023) Hasar, Hafize; Hasar, Ugur C.; Kaya, Yunus; Ozturk, Hamdullah; Izginli, Mucahit; Oztas, Taskin; Aslan, Nevzat
    Microwave techniques, as an indirect approach, can be applied for analyzing water content in honey by way of permittivity measurements. However, these techniques require proper calibration to accurately perform such indirect evaluation. Improper calibration standards used in this calibration process could naturally result in a reduction in the accuracy and thus the performance of dielectric characterization using microwaves. Self-calibrating microwave techniques can reduce the effects of imprecise standards and thus improve the performance of microwave measurements by bypassing the requirement of calibration standards. In this study, we develop a self-calibrating microwave measurement technique to determine the relative permittivity of honey samples and implement binary mixing models to predict adulteration levels of water-adulterated honey. From this implementation, it is observed that the parallel-capacitance mixing model could efficiently be applied to determine the concentration of water adulteration by examining the differences between absolute values of the real parts of the measured and predicted complex permittivities of adulterated honey.
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    Honey-Water Content Analysis by Mixing Models Using a Self-Calibrating Microwave Method
    (Institute of Electrical and Electronics Engineers Inc., 2023) Hasar, Hafize; Cem Hasar, Ugur Cem; Kaya, Yunus; Ozturk, Hamdullah; Izginli, Mucahit; Öztaş, Taşkin; Ramahi, Omar Mustafa
    Microwave techniques, as an indirect approach, can be applied for analyzing water content in honey by way of permittivity measurements. However, these techniques require proper calibration to accurately perform such indirect evaluation. Improper calibration standards used in this calibration process could naturally result in a reduction in the accuracy and thus the performance of dielectric characterization using microwaves. Self-calibrating microwave techniques can reduce the effects of imprecise standards and thus improve the performance of microwave measurements by bypassing the requirement of calibration standards. In this study, we develop a self-calibrating microwave measurement technique to determine the relative permittivity of honey samples and implement binary mixing models to predict adulteration levels of water-adulterated honey. From this implementation, it is observed that the parallel-capacitance mixing model could efficiently be applied to determine the concentration of water adulteration by examining the differences between absolute values of the real parts of the measured and predicted complex permittivities of adulterated honey. © 1963-2012 IEEE.
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    Prediction of water-adulteration within honey by air-line de-embedding waveguide measurements
    (Elsevier Sci Ltd, 2021) Hasar, Hafize; Hasar, Ugur Cem; Kaya, Yunus; Ozturk, Hamdullah; Izginli, Mucahit; Ozbek, Ibrahim Yucel; Oztas, Taskin
    An efficient de-embedding air-line microwave method has been proposed for accurate relative complex permittivity, epsilon(r) = epsilon(r)' - i epsilon(r)'', measurement of water-adulteration level within honey. It could be effectively applied to eliminate the errors arising from usage of imperfect calibration standards because it bypasses the requirement of these standards. Its accuracy is improved by utilizing the unitary and similarity properties of a passive two-port network, and then is compared with the accuracy of a calibration-dependent method present in the literature by using normalized root-mean-square-error (N-RMSE) values of epsilon(r)' and epsilon(r)'' of distilled water, in reference to the Debye value. From this comparison, it is observed that N-RMSE values calculated for epsilon(r)' (and epsilon(r)'') by using this calibration-dependent method and the (improved) proposed method are, respectively, around 0.1955 (0.1002) and 0.1962 (1.1067), indicating a good agreement between them. After validation the proposed de-embedding method using distilled water measurements, tested pure honey was adulterated with distilled water by different percentage values delta ranging from 1% to 10% in 1% increments. It is observed that the maximum distance between extracted epsilon(r)' (or epsilon(r)'') values of adulterated honey by the applied calibration-dependent method and the proposed method is less than 2%. Afterward, an empirical formula was devised to fit epsilon(r)' and epsilon(r)'' values from measured epsilon(r) of water-adulterated honey with various delta levels. It is noted that extracted epsilon(r)' is much more better fitted than extracted epsilon(r)'', especially for delta <= 4. Next, an optimization process is followed to evaluate the frequency for optimum prediction of adulteration levels using the empirical formula based on epsilon(r)' or epsilon(r)'' It is noticed that optimized delta values using the empirical formula based on epsilon(r)' (with an average prediction error of around 0.071 at 4.5 GHz) are superior to optimized delta values using the empirical formula based on epsilon(r)'' (with an average prediction error of around 0.085 at 4.2 GHz) for prediction of previously known delta values. Sensitivity and uncertainty analyses were performed to assess and improve the accuracy of the proposed method.
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    Quantification of Honey Adulteration Using a Planar Microstrip Metamaterial-Motivated Sensor and Software-Defined Radio
    (Ieee-Inst Electrical Electronics Engineers Inc, 2025) Cem Hasar, Ugur; Hasar, Hafize; Kaya, Yunus; Ozturk, Hamdullah; Korkmaz, Huseyin; Kosunalp, Selahattin; Mustafa Ramahi, Omar
    This work presents the application of a planar microstrip metamaterial (MM)-motivated sensor in the form of a split-ring resonator (SRR) for the detection and quantification of water adulteration in honey samples. The proposed sensor utilizes inexpensive software-defined radio (SDR) measurements, offering a cost-effective solution. Unlike previous MM sensors employing SRR configuration, our proposed MM-motivated sensor is integrated with a microstrip feedline and an additional vertical bar, enhancing its sensing capability. To enable accurate measurements, a simple calibration procedure based on baseline normalization is implemented, allowing for amplitude-only transmission measurements (|S-21|) using the SDR. A special sample holder was designed to increase the repeatability of measurements. We separately employ two postprocessing techniques, namely, the rolling average (RA) approach and the Savitzky-Golay (SG) filter, to effectively eliminate ripples in the measured |S-21| data obtained from the SDR. For validation and evaluation of the proposed sensor and postprocessing techniques, measurements of flower honey samples with water adulteration levels (delta ) up to 10% (mass-to-mass basis) were also performed using a vector network analyzer (VNA). The resonance frequency of |S21| is utilized as the basis for analysis. We establish a metric function (linear function) that correlates the shift in resonance frequency with delta. It is observed that this function fits to measured resonance frequency values with an R(2 )value greater than 0.96 for both postprocessing techniques with or without the sample holder. By inverting this function, we can predict delta with considerable accuracy for a given resonance frequency by using another linear function. It is observed that percentage variations between predicted and measured delta values are between 1.54% and 6.46% for testing samples with delta = 5% and delta = 7%.
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    Sensitive Microwave Sensor for Detection and Quantification of Water in Adulterated Honey
    (Ieee-Inst Electrical Electronics Engineers Inc, 2025) Hasar, Hafize; Hasar, Ugur Cem; Kaya, Yunus; Ozturk, Hamdullah; Korkmaz, Huseyin; Yuzgulec, Kadir; Ramahi, Omar M.
    Honey is a rich source of sugar and is one of the indispensable ingredients in infant foods. Thus, it can be subjected to adulteration due to its cost. Measurement techniques such as liquid chromatography and near-infrared spectroscopy, used for detecting any adulteration, are expensive and need to be conducted by highly trained personnel for off-line analysis. Microwave measurements, as a fast, simple, and relatively inexpensive analysis, have recently shown great potential in detecting adulteration within honey samples. Nonetheless, sensor types used in such measurements are conventional. In this study, a reflection-type sensitive microwave sensor terminated by a metal back is proposed for the first time in the literature for the detection and quantification of water percentage ( delta ) level (mass-to-mass basis) within water-adulterated honey samples. When compared with other resonance-based microwave cavity sensors, thanks to its eight strips located at the centers of two closed circular loops, it demonstrates superior frequency selectivity and sensitivity ( S=5.13 %) validated by full-wave 3-D simulations performed by the CST Microwave Studio and equivalent circuit analysis carried out by the Advanced Design System (ADS) software. For example, for ethanol, the proposed sensor gives a frequency shift of more than 1 GHz in the X band. Resonance frequency shift and variation of the reflection coefficient amplitude ( |S11| ) are measured at X band to detect honey samples with up to 8% adulteration level. Three different honey samples (flower honey, highland honey, and thyme honey) were examined to test the performance and applicability of the proposed sensor.
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    Simple and inexpensive microwave setup for industrial based applications: Quantification of flower honey adulteration as a case study
    (Nature Portfolio, 2024) Hasar, Ugur C.; Hasar, Hafize; Ozturk, Hamdullah; Korkmaz, Huseyin; Kaya, Yunus; Ozkaya, Mehmet Akif; Ebrahimi, Amir
    A simple and inexpensive microwave measurement setup based on measurements of magnitudes of transmission properties ( | S 21 | dB \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$|S_{21}|_{\text {dB}}$$\end{document} ) is proposed for industrial-based microwave aquametry (moisture or water content) applications. An easy-to-apply calibration procedure based on normalization is implemented to eliminate systematic errors in the measurement system. As a case study, we applied this setup for the quantification of water-adulteration in flower honey. After validating this system by distilled water and pure flower honey measurements, | S 21 | dB \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$|S_{21}|_{\text {dB}}$$\end{document} measurements of the pure flower honey with various adulteration percentages ( delta \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\delta$$\end{document} ) up to 9% are conducted to examine the performance of the measurement setup for quantification of water adulteration. A multi-dimensional fitting procedure is implemented to predict delta \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\delta$$\end{document} using the proposed inexpensive microwave measurement setup. It is shown that it is possible to quantify an adulteration level with an accuracy better than -/+ 1 \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${\mp } 1$$\end{document} % by the proposed measurement setup and the applied multi-dimensional fitting procedure.