The Experts below are selected from a list of 95298 Experts worldwide ranked by ideXlab platform
Ugur Cem Hasar - One of the best experts on this subject based on the ideXlab platform.
-
reference invariant permittivity and thickness measurement of lossy liquid materials
Electronics Letters, 2017Co-Authors: Ugur Cem Hasar, Musa ButeAbstract:A Microwave Method has been proposed to retrieve the complex permittivity and thickness of lossy dielectric liquids, which result in at least 10 dB attenuation, using reference-plane-invariant reflection scattering (S-) parameters. The CST Microwave Studio simulation program was first used to validate the Method. Then, the permittivity and thickness of lossy distilled water sample poured over a polyethylene sample holder were measured from reference-invariant reflection-only S-parameter measurements at the X-band. The Method was compared with other Methods in the literature to analyse its accuracy.
-
Determination of Reference-Plane Invariant, Thickness-Independent, and Broadband Constitutive Parameters of Thin Materials
IEEE Transactions on Microwave Theory and Techniques, 2015Co-Authors: Ugur Cem Hasar, Joaquim José Barroso, Yunus Kaya, Mehmet ErtugrulAbstract:We propose an effective Microwave Method for reference-plane-invariant and thickness-independent constitutive parameters measurement of thin materials. A function depending only on the interface reflection coefficient to facilitate fast computations of constitutive parameters is derived. In addition to the extraction of sample thickness, the Method can also be applied to unique retrieval of constitutive parameters whose electromagnetic properties are yet unknown. We have performed an uncertainty analysis to examine how the accuracy of the Method can be improved. Finally, we have compared the proposed Method with other similar Methods in the literature using measurements of distilled water and a thinner Plexiglas sample (1 mm). From the comparison, we note that the accuracy of our proposed Method is not affected by any inaccurate knowledge of reference-plane positions and the sample length (or both) while those of compared Methods are seriously decreased.
-
Microwave Method for reference-plane-invariant and thickness-independent permittivity determination of liquid materials.
The Review of scientific instruments, 2014Co-Authors: Ugur Cem Hasar, Musa Bute, Joaquim José Barroso, Yunus Kaya, Mehmet ErtugrulAbstract:An attractive transmission-reflection Method based on reference-plane invariant and thickness-independent expressions has been proposed for accurate and unique retrieval of complex permittivity of dielectric liquid samples. The Method uses both branch-index-independent expressions and a restricted solution set for determining unique and fast complex permittivities. A 2D graphical Method has been applied to demonstrate the operation and validation of the proposed Method. A uncertainty analysis has been performed to monitor how the accuracy of the proposed Method can be improved by a correct selection of sample holder properties. Scattering parameter measurements of two tested reference liquids (distilled water and methanol) have been carried out for comparison of various techniques with the proposed one when the reference-planes and sample thickness are not precisely known. We note from the comparison that whereas other techniques are seriously affected by imprecise knowledge of both reference-planes and sample thickness, the proposed Method removes this restriction.
-
unique permittivity determination of low loss dielectric materials from transmission measurements at Microwave frequencies
Progress in Electromagnetics Research-pier, 2010Co-Authors: Ugur Cem HasarAbstract:A non-resonant Microwave Method has been proposed for accurate complex permittivity determination of low-loss materials. The Method uses two measurement data of the magnitude of transmission properties of the sample. While the flrst datum must correspond to a frequency point resulting in a maximum magnitude of transmission properties, the other can be any datum at a frequency difierent than the flrst datum and not far distant from the flrst datum. Two closed-from expressions are derived for a good initial guess using the above data. The limitations of each expression are discussed. The Method has been validated by transmission measurements at X-band (8.2{12.4GHz) of a low-loss sample located into a waveguide sample holder.
-
thickness independent complex permittivity determination of partially filled thin dielectric materials into rectangular waveguides
Progress in Electromagnetics Research-pier, 2009Co-Authors: Ugur Cem HasarAbstract:A Microwave Method has been proposed for accurate complex permittivity measurement of thin dielectric materials partially fllling the waveguide. The Method employs propagation constant measurements at two locations of the sample inside its holder. It increases the accuracy of permittivity measurements of similar Methods in the literature since it utilizes the measurements of the distances between the inner waveguide walls and sample lateral surfaces instead of directly measuring the sample thickness. It has been validated by comparing the measured complex permittivity of a thin Plexiglas sample by the proposed Method with that of the Method in the literature.
Mehmet Ertugrul - One of the best experts on this subject based on the ideXlab platform.
-
Determination of Reference-Plane Invariant, Thickness-Independent, and Broadband Constitutive Parameters of Thin Materials
IEEE Transactions on Microwave Theory and Techniques, 2015Co-Authors: Ugur Cem Hasar, Joaquim José Barroso, Yunus Kaya, Mehmet ErtugrulAbstract:We propose an effective Microwave Method for reference-plane-invariant and thickness-independent constitutive parameters measurement of thin materials. A function depending only on the interface reflection coefficient to facilitate fast computations of constitutive parameters is derived. In addition to the extraction of sample thickness, the Method can also be applied to unique retrieval of constitutive parameters whose electromagnetic properties are yet unknown. We have performed an uncertainty analysis to examine how the accuracy of the Method can be improved. Finally, we have compared the proposed Method with other similar Methods in the literature using measurements of distilled water and a thinner Plexiglas sample (1 mm). From the comparison, we note that the accuracy of our proposed Method is not affected by any inaccurate knowledge of reference-plane positions and the sample length (or both) while those of compared Methods are seriously decreased.
-
Microwave Method for reference-plane-invariant and thickness-independent permittivity determination of liquid materials.
The Review of scientific instruments, 2014Co-Authors: Ugur Cem Hasar, Musa Bute, Joaquim José Barroso, Yunus Kaya, Mehmet ErtugrulAbstract:An attractive transmission-reflection Method based on reference-plane invariant and thickness-independent expressions has been proposed for accurate and unique retrieval of complex permittivity of dielectric liquid samples. The Method uses both branch-index-independent expressions and a restricted solution set for determining unique and fast complex permittivities. A 2D graphical Method has been applied to demonstrate the operation and validation of the proposed Method. A uncertainty analysis has been performed to monitor how the accuracy of the proposed Method can be improved by a correct selection of sample holder properties. Scattering parameter measurements of two tested reference liquids (distilled water and methanol) have been carried out for comparison of various techniques with the proposed one when the reference-planes and sample thickness are not precisely known. We note from the comparison that whereas other techniques are seriously affected by imprecise knowledge of both reference-planes and sample thickness, the proposed Method removes this restriction.
Bala Vaidhyanathan - One of the best experts on this subject based on the ideXlab platform.
-
Microwave sintering of multilayer integrated passive devices
Journal of the American Ceramic Society, 2010Co-Authors: Bala Vaidhyanathan, Ketharam Annapoorani, Jon G P Binner, Ramya RaghavendraAbstract:Microwave sintering of multilayer capacitor/varistor-based integrated passive devices (IPDs) has been investigated for the first time. The sintered samples were characterized for density, microstructure, composition, and electrical performance. It was found that IPDs with varistor/capacitor formulations could be Microwave sintered to fully dense device components within 3 h of total cycle time, which is <1/10th of the time required by conventional Methods. Microwave sintering resulted in products with a finer grain structure and without delamination or significant interdiffusion between the ceramic/electrode and varistor/capacitor interfaces. The Microwave Method also completely eliminated the need for a separate binder burnt-out step. The electrical properties of the Microwave-sintered samples were found to better or match those obtained by conventional, industrial processing. In general, the simplicity, rapidity, and superior product performance make the Microwave technique an attractive sintering Methodology for the processing of IPDs.
-
Microwave assisted synthesis of nanocrystalline yag
Journal of Materials Science, 2006Co-Authors: Bala VaidhyanathanAbstract:Using nitrate precursors, a novel Microwave assisted citrate gel process for the preparation of nanocrystalline yttrium aluminium garnet (YAG) phase has been developed. Synthesis of single phase polycrystalline YAG was achieved at temperatures as low as 600 °C using the Microwave Methodology whilst conventional approaches currently available require ≥1000 °C. The Microwave prepared YAG powder was characterised using X-ray diffraction, FTIR spectroscopy, TEM and EDAX. The Microwave Method was found to yield YAG particles of ∼40 nm diameter, whilst the conventional route yielded 150 nm particles. Also substantial morphological differences were observed between the YAG particles and their agglomerates produced by the different processing Methods.
Yunus Kaya - One of the best experts on this subject based on the ideXlab platform.
-
Determination of Reference-Plane Invariant, Thickness-Independent, and Broadband Constitutive Parameters of Thin Materials
IEEE Transactions on Microwave Theory and Techniques, 2015Co-Authors: Ugur Cem Hasar, Joaquim José Barroso, Yunus Kaya, Mehmet ErtugrulAbstract:We propose an effective Microwave Method for reference-plane-invariant and thickness-independent constitutive parameters measurement of thin materials. A function depending only on the interface reflection coefficient to facilitate fast computations of constitutive parameters is derived. In addition to the extraction of sample thickness, the Method can also be applied to unique retrieval of constitutive parameters whose electromagnetic properties are yet unknown. We have performed an uncertainty analysis to examine how the accuracy of the Method can be improved. Finally, we have compared the proposed Method with other similar Methods in the literature using measurements of distilled water and a thinner Plexiglas sample (1 mm). From the comparison, we note that the accuracy of our proposed Method is not affected by any inaccurate knowledge of reference-plane positions and the sample length (or both) while those of compared Methods are seriously decreased.
-
Microwave Method for reference-plane-invariant and thickness-independent permittivity determination of liquid materials.
The Review of scientific instruments, 2014Co-Authors: Ugur Cem Hasar, Musa Bute, Joaquim José Barroso, Yunus Kaya, Mehmet ErtugrulAbstract:An attractive transmission-reflection Method based on reference-plane invariant and thickness-independent expressions has been proposed for accurate and unique retrieval of complex permittivity of dielectric liquid samples. The Method uses both branch-index-independent expressions and a restricted solution set for determining unique and fast complex permittivities. A 2D graphical Method has been applied to demonstrate the operation and validation of the proposed Method. A uncertainty analysis has been performed to monitor how the accuracy of the proposed Method can be improved by a correct selection of sample holder properties. Scattering parameter measurements of two tested reference liquids (distilled water and methanol) have been carried out for comparison of various techniques with the proposed one when the reference-planes and sample thickness are not precisely known. We note from the comparison that whereas other techniques are seriously affected by imprecise knowledge of both reference-planes and sample thickness, the proposed Method removes this restriction.
Joaquim José Barroso - One of the best experts on this subject based on the ideXlab platform.
-
Determination of Reference-Plane Invariant, Thickness-Independent, and Broadband Constitutive Parameters of Thin Materials
IEEE Transactions on Microwave Theory and Techniques, 2015Co-Authors: Ugur Cem Hasar, Joaquim José Barroso, Yunus Kaya, Mehmet ErtugrulAbstract:We propose an effective Microwave Method for reference-plane-invariant and thickness-independent constitutive parameters measurement of thin materials. A function depending only on the interface reflection coefficient to facilitate fast computations of constitutive parameters is derived. In addition to the extraction of sample thickness, the Method can also be applied to unique retrieval of constitutive parameters whose electromagnetic properties are yet unknown. We have performed an uncertainty analysis to examine how the accuracy of the Method can be improved. Finally, we have compared the proposed Method with other similar Methods in the literature using measurements of distilled water and a thinner Plexiglas sample (1 mm). From the comparison, we note that the accuracy of our proposed Method is not affected by any inaccurate knowledge of reference-plane positions and the sample length (or both) while those of compared Methods are seriously decreased.
-
Microwave Method for reference-plane-invariant and thickness-independent permittivity determination of liquid materials.
The Review of scientific instruments, 2014Co-Authors: Ugur Cem Hasar, Musa Bute, Joaquim José Barroso, Yunus Kaya, Mehmet ErtugrulAbstract:An attractive transmission-reflection Method based on reference-plane invariant and thickness-independent expressions has been proposed for accurate and unique retrieval of complex permittivity of dielectric liquid samples. The Method uses both branch-index-independent expressions and a restricted solution set for determining unique and fast complex permittivities. A 2D graphical Method has been applied to demonstrate the operation and validation of the proposed Method. A uncertainty analysis has been performed to monitor how the accuracy of the proposed Method can be improved by a correct selection of sample holder properties. Scattering parameter measurements of two tested reference liquids (distilled water and methanol) have been carried out for comparison of various techniques with the proposed one when the reference-planes and sample thickness are not precisely known. We note from the comparison that whereas other techniques are seriously affected by imprecise knowledge of both reference-planes and sample thickness, the proposed Method removes this restriction.