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- MakaleAçık Erişim2024Scopus SJRQ1Simpler Reference-Plane-Invariant Method for Permittivity Extraction of Medium- or Low-Loss Dielectric Samples Using One-Port Measurements
Cem Hasar, Ugur; Ali, Husain; Kaya, Yunus; Stoyanov, Ivaylo
A microwave method is devised to extract relative complex permittivity (ϵr) of medium- or low-loss dielectric samples. It is simpler, non-iterative, reference-plane-invariant (RPI), and applicable for one-port waveguide measurements with short-circuit termination only. Besides, since it uses short-circuit termination reflection-only measurements, it is free from Fabry-Pérot resonances. Permittivity measurements of polyvinyl chloride (PVC) and polypropylene (PP) are performed at X-band (8.2-12.4 GHz) to examine the performance of the proposed method considering different scenarios involving inaccurate information of sample location in the cell and inaccurate knowledge of the sample thickness. Repeatability analysis is carried out to analyze the performance of the proposed method against other similar methods in the literature.
AtıfScopus6WoS5
İncele - MakaleYalnız künye2023Scopus SJRQ1Parameter extraction method for reflection-asymmetric bianisotropic metamaterial slabs using one-port measurements
Hasar, Ugur Cem; Kaya, Yunus; Ozturk, Hamdullah; Ertugrul, Mehmet; Ramahi, Omar Mustafa
An effective microwave method is developed for extracting electromagnetic properties of bianisotropic metamaterial (MM) slabs. As a non-iterative method, it utilizes only the one-port (air-backed and metal-backed MM slab) scattering (S-) parameter measurements. This is a useful feature especially for vector network analyzers, such as MS46131A, MS46121B, and R60, performing only one-port S-parameter measurements. Electromagnetic properties of a bianisotropic MM slab formed by C-shaped resonators are measured by an X-band (8.2–12.4 GHz) rectangular waveguide setup. The effect of any gap between the short-circuit termination for metal-backed measurements and the end of the MM slab on extracted electromagnetic properties is also examined for evaluating the possible error for proposed method.
AtıfScopus3WoS3OpenAlex5İncele - MakaleAçık Erişim2013Scopus SJRQ1Reference-plane invariant transmission-reflection method for measurement of constitutive parameters of liquid materials
Hasar, Ugur Cem; Barroso, Joaquim José; Kaya, Yunus; Ertugrul, Mehmet; Bute, Musa
We propose a new transmission-reflection method for measuring constitutive parameters of liquid samples inside an asymmetric measurement cell (a sample over a low-loss holder in vertical position inside an empty waveguide section). We derived reference-plane invariant expressions for constitutive parameters measurement of liquid samples from reference-plane dependent scattering parameters. In addition, we also applied a simple approach for unique determination of transformation factor and reference-plane distances. After, we also investigated how the performance of the proposed method could be improved by performing a differential uncertainty analysis. From this analysis, we found the following key results: (a) the accuracy of the proposed method could be enhanced for low-loss liquid samples by using thicker samples, and (b) the effect of constitutive parameters and the length of the (low-loss) sample holder on constitutive parameters measurements of liquid samples by the proposed method is a key parameter in increasing the accuracy of the measurements. Finally, we performed constitutive parameter measurements of distilled water and methanol to validate the proposed method and compared the proposed method with similar methods in the literature. From the measurements, we note that our method is especially useful for liquid sample measurements when the reference-plane transformation factors are not known a priori and/or if the measurements are carried out over a high frequency range.
AtıfScopus20WoS19OpenAlex22İncele