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Öğe 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, MehmetA 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.Öğe Broadband, Stable, and Noniterative Dielectric Constant Measurement of Low-Loss Dielectric Slabs Using a Frequency-Domain Free-Space Method(IEEE-Inst Electrical Electronics Engineers Inc, 2022) Hasar, Ugur C.; Kaya, Yunus; Ozturk, Gokhan; Ertugrul, Mehmet; Korasli, CelalA broadband, stable, and noniterative free-space method is proposed for dielectric constant epsilon'(r) determination of low-loss dielectric slabs from reflection-only measurements through simple calibration standards (reflect and air). It is applicable for dispersive samples and does not require thickness information. Simulations of nondisperive and dispersive samples are performed to validate our method. Dielectric constant measurements of polyethylene and polyoxymethylene samples (9-11 GHz) are carried out to examine the accuracy of our method.Öğe Calibration-Free Time-Domain Free-Space Permittivity Extraction Technique(IEEE-Inst Electrical Electronics Engineers Inc, 2022) Hasar, Ugur C.; Ozturk, Gokhan; Kaya, Yunus; Ertugrul, MehmetA time-domain free-space technique has been proposed to extract relative permittivity (epsilon(r)) and effective conductivity (sigma(e)) of low-loss dielectric samples using their metal- and air-backed calibration-free reflected powers. Numerical computations and 3-D electromagnetic simulations were performed to validate the method. A sensitivity analysis was carried out to examine its accuracy. Calibration-free time-domain free-space measurements over 1-12 GHz were conducted by VNA to extract epsilon(r) and sigma(e) of polyethylene and polypropylene low-loss samples.Öğe Determination of Propagation Constants and Wave Impedance of Non-Reciprocal Networks From Position-Insensitive Waveguide Measurements(IEEE-Inst Electrical Electronics Engineers Inc, 2022) Hasar, Ugur C.; Kaya, Yunus; Izginli, Mucahit; Ozturk, Hamdullah; Barroso, Joaquim J.; Ramahi, Omar M.; Ertugrul, MehmetA microwave method is proposed to determine the forward and backward propagation constants (gamma ? and gamma ?) and the wave impedance ( $z_{w}$ ) of reciprocal and non-reciprocal microwave networks whose positions are not known within their measurement cells (position-insensitive). The proposed method relies purely on analytical expressions and can also evaluate the reference plane transformation distances. Scattering parameter measurements at the X-band (8.2-12.4 GHz) of a reciprocal network (a waveguide straight) and a non-reciprocal network (a microwave phase shifter) arbitrarily positioned into their measurement cells were conducted to retrieve gamma ?, gamma ?, and $z_{w}$ for validation of our method and testing its position-insensitive property. The importance of the method becomes apparent when compared to conventional methods whose accuracy is based on precise determination of the reference planes.Öğe Extraction Method for Unique Determination of Complex Permittivity From Graphical Analysis of Natural Frequencies(IEEE-Inst Electrical Electronics Engineers Inc, 2023) Hasar, Ugur C.; Ozturk, Gokhan; Kaya, Yunus; Alfaqawi, Mona S. S.; Barroso, Joaquim Jose; Ertugrul, Mehmet; Ramahi, Omar M.A time-domain free-space extraction procedure is proposed to uniquely determine the relative complex permittivity epsilon(r)(omega) based on two sets of natural frequencies of the metal- and air-backed dielectric samples. A graphical analysis is applied for evaluating whether unique epsilon(r)(omega) can be extracted using such natural frequencies. The method is numerically validated using two dielectric samples with different epsilon(omega) for the ideal case (no noise) and under the influence of noise with different signal-to-noise ratios (SNRs).Öğe Graphical Method for Examining Complex Natural Frequencies of Dispersive Materials(IEEE-Inst Electrical Electronics Engineers Inc, 2021) Hasar, Ugur C.; Ozturk, Gokhan; Barroso, Joaquim J.; Gurbuz, Tolga U.; Kaya, Yunus; Ertugrul, MehmetA graphical method is extended to and applied for visual inspection of solution patterns (region of complex natural frequencies sn) in the complex s-plane for dispersive materials characterized by the Debye and Lorentz models. These patterns are in the form of exponential decay and C-shaped profiles for the Debye and Lorentz models, respectively. Their forms are observed to be affected (e.g., moving left/right) in different manners with a variation of dispersion parameters. This method, thanks to its visual inspection capability, can help in analyzing/synthesizing filters and frequency-selective surfaces.Öğe 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, NevzatMicrowave 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.Öğe Measurement of Propagation Characteristics of Nonreciprocal Networks/Lines Using a Line-Line Method(IEEE-Inst Electrical Electronics Engineers Inc, 2021) Hasar, Ugur C.; Kaya, Yunus; Ertugrul, MehmetIn this article have proposed a new calibration-free line-line method for propagation constant (gamma) determination of homogeneous nonreciprocal networks or lines with symmetric reflection property. To achieve our goal, wave-cascading matrices for impedance, amplitude, and phase changes for a line step from a homogeneous reciprocal network or line to a homogeneous nonreciprocal network or line (and vice versa). Two different approaches based on the proposed line-line method are proposed for unique extraction of gamma in forward and backward directions. Measurements of gamma for two reciprocal lines (waveguide straights at X-band and Ku-band with different lengths) and a nonreciprocal line (microwave phase shifter) were first carried out and then compared with measured gamma of these lines by different methods to validate our method and monitor its accuracy.Öğe Simple and Accurate Electromagnetic Characterization of Omega-Class Bianisotropic Metamaterials Using the State Transition Matrix Method(IEEE-Inst Electrical Electronics Engineers Inc, 2021) Hasar, Ugur C.; Ozturk, Gokhan; Kaya, Yunus; Barroso, Joaquim J.; Ertugrul, MehmetWe propose a simple and accurate microwave extraction procedure for full electromagnetic characterization of Omega-class bianisotropic metamaterial (MM) slabs from normal incidence scattering (S-) parameters using TE1, TE2, and TE3 modes. Its closed-form nature (no need for any numerical analysis and optimization toolbox) and less requirement (a total of seven S-parameters) demonstrate the advantage of our method over other methods in the literature. Our approach was validated and its accuracy was verified by S-parameters, through a full electromagnetic simulation program-CST Microwave Studio, of an edge-coupled Omega-class split-ring-resonator MM slab.Öğe 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, AmirA 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.Öğe Temporal Reflection Response of Plane Waves Within an N-Layer Structure Involving Bianisotropy(IEEE-Inst Electrical Electronics Engineers Inc, 2023) Hasar, Ugur C.; Ozturk, Gokhan; Kaya, Yunus; Barroso, Joaquim Jose; Ertugrul, Mehmet; Ramahi, Omar M.; Alfaqawi, Mona S. S.The temporal reflection response of an N-layer composite structure involving bianisotropic behavior is examined for the first time in the literature. Toward this goal, the wave matrix (WM) method, which is fundamental, relatively easier to apply, and compact and iterative suitable for analysis of multilayer structures, is first extended to the analysis of an interface separating two different media involving bianisotropy. Next, the reflection response of the whole structure is derived in terms of series form to better analyze its temporal behavior. Then, frequency-domain and time-domain responses of the whole structure are expressed using a special reflection coefficient (the reduced reflection coefficient) by way of the concept of subregions. A numerical analysis is performed to demonstrate the applicability of our formalism for two different polarization types (perpendicular and parallel).
