In this paper, a fast and efficient algorithm for the evaluation of relative permittivity of a solid dielectric sample, when measured by a microstrip ring resonator, is proposed. It is verified for permittivity values up to 10 and material-under-test thicknesses up to 8 mm, which cover a wide range of prospective materials that may be used in electronics and communications. The algorithm was tested on 11 samples of various permittivity values and thicknesses and showed a very good agreement with their nominal permittivity values. The maximum error was within 10% even for the sample thicker than 7 mm, while the results for the four standard laminates (TLX8-060, RF60A-0300, RF60A-0620, and FR4) showed an average error of 2.34%. Attractive features of the proposed algorithm are that the results contained in the reference set are frequency-scalable, applicable to many pairs of unknown permittivity and sample thickness values, unbiased, and easily appendable with additional reference points if higher accuracy is sought.
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http://dx.doi.org/10.3390/s22155591 | DOI Listing |
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January 2025
Department of Physics, Indian Institute of Technology Guwahati, Guwahati, 781039, India.
The desire to reduce secondary pollution from shielded electronics devices demands electromagnetic interference (EMI) shields with high green index (GI), which is the ratio of absorbance over reflectance. Achieving high GI values simultaneously with high shielding effectiveness (SE) over 50 dB is a serious unresolved challenge. Reducing the impedance mismatch between the shield and free space is the key to reducing the reflection of incoming radiation and enabling more penetration into the body of the shield for absorption.
View Article and Find Full Text PDFMaterials (Basel)
January 2025
Institute of Microelectronics and Optoelectronics, Warsaw University of Technology, Koszykowa 75, 00-662 Warsaw, Poland.
A review of natural materials that exhibit negative permittivity or permeability, including gaseous plasma, metals, superconductors, and ferromagnetic materials, is presented. It is shown that samples made of such materials can store large amount of the electric (magnetic) energy and create plasmonic resonators for certain values of permittivity, permeability, and dimensions. The electric and the magnetic plasmon resonances in spherical samples made of such materials are analyzed using rigorous electrodynamic methods, and the results of the analysis are compared to experimental data and to results obtained with other methods.
View Article and Find Full Text PDFMaterials (Basel)
January 2025
Institute of Technology, University of the National Education Commission, Podchorążych 2, 30-084 Kraków, Poland.
In this work, three composite materials based on Terfenol-D and PZT-type material were obtained with a classic sintering method using a combination of 0-3 phases, where the ferroelectric phase was doped PZT material (P) and the magnetic phase was Terfenol-D (T). The percentage of P and T components in the composites was variable, i.e.
View Article and Find Full Text PDFJ Comput Chem
January 2025
Department of Mechanical Engineering, Universidad Técnica Federico Santa María, Valparaíso, Chile.
The standard Poisson-Boltzmann (PB) model for molecular electrostatics assumes a sharp variation of the permittivity and salt concentration along the solute-solvent interface. The discontinuous field parameters are not only difficult numerically, but also are not a realistic physical picture, as it forces the dielectric constant and ionic strength of bulk in the near-solute region. An alternative to alleviate some of these issues is to represent the molecular surface as a diffuse interface, however, this also presents challenges.
View Article and Find Full Text PDFAnal Chem
January 2025
Department of Anesthesiology, Tokyo Medical and Dental University, Graduate School of Medical and Dental Sciences, 1-5-45 Yushima, Bunkyo-ku 113-8510, Tokyo, Japan.
The hemostatic function of platelets is complementary to blood coagulation. However, traditional platelet function tests have primarily focused on measuring platelet aggregation, reducing their clinical effectiveness for antiplatelet drug monitoring. To address this limitation, we propose a new test principle that evaluates platelet function and the effects of antiplatelet drugs through blood coagulation reactions.
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