scholarly journals Errors in Broadband Permittivity Determination Due to Liquid Surface Distortions in Semi-Open Test Cell

2021 ◽  
Vol 13 (5) ◽  
pp. 983
Author(s):  
Michał Kalisiak ◽  
Wojciech Wiatr
Keyword(s):  
Liquid Surface ◽  
Test Cell ◽  
Distilled Water ◽  
Scattering Parameters ◽  
Frequency Range ◽  
Electromagnetic Simulations ◽  
Liquid Samples ◽  
Open Test ◽  
Surface Distortions ◽  
Removal Technique

We study how surface distortions of liquid samples due to a meniscus and a tilt of a semi-open coaxial test cell affect errors in a broadband permittivity determination. The study is based on the scattering parameters, obtained using the electromagnetic simulations of samples with flat and distorted surfaces in a broad frequency range up to 18 GHz. The parameters are processed with the classic Nicolson–Ross–Weir (NRW) method and our new meniscus removal technique. We analyze the errors for several samples of different properties, such as distilled water and propan-2-ol. The results show that the meniscus removal technique is more robust and provides smaller errors in the permittivity determination compared to the classic NRW method. The effect of the cell tilt, to our best knowledge, has not been considered in the literature yet.

scholarly journals Miniaturized Coplanar Waveguide for Nanostructured Magnetostrictive Multilayer Characterization

Proceedings ◽  
2019 ◽  
Vol 2 (13) ◽  
pp. 851
Author(s):  
Abdelhatif El Fellahi ◽  
Aurélien Mazzamurro ◽  
Jean Claude Gerbedoen ◽  
Yannick Dusch ◽  
Olivier Bou Matar ◽  
...  
Keyword(s):  
Coplanar Waveguide ◽  
Complex Permeability ◽  
Network Analyzer ◽  
Scattering Parameters ◽  
Frequency Range ◽  
Electromagnetic Simulations ◽  
Insertion Losses ◽  
The Magnetic Field ◽  
Large Frequency ◽  
Permeability Spectrum

A miniaturized coplanar waveguide (CPW) on a Y-cut LiNbO3 substrate operating in Radio Frequency region (RF) is proposed for studying of magnetostrictive multi-layered structure. The structure is composed of a 14 × [TbCo2 (3.7 nm)/FeCo (4 nm)] nanostructured multi-layer. Using microtechnology process, the miniaturized CPW has been designed with a 50 µm wide signal line in the frequency range from 6 MHz to 6 GHz. Electromagnetic simulations based on ®Ansys/HFSS demonstrate insertion losses less than 2 dB and show that the magnetic field is more confined in the nanostructured multi-layer placed on top of the micro-sized CPW. By using Vectorial Network Analyzer (VNA) the Ferromagnetic Resonance (FMR) is investigated from the reflection (Sii) or transmission (Sij) coefficients of scattering parameters. An inversion model is finally used to extract the complex permeability spectrum of the thin-film in a large frequency range.

scholarly journals Detection and estimating the blood accumulation volume of brain hemorrhage in a human anatomical skull using a RF single coil

PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e10416
Author(s):  
Moshe Oziel ◽  
Boris Rubinsky ◽  
Rafi Korenstein
Keyword(s):  
Experimental Study ◽  
Electromagnetic Radiation ◽  
Hemorrhagic Stroke ◽  
Average Error ◽  
Tissue Fluid ◽  
Brain Hemorrhage ◽  
Scattering Parameters ◽  
Frequency Range ◽  
Single Coil ◽  
Chicken Blood

Objective An experimental study for testing a simple robust algorithm on data derived from an electromagnetic radiation device that can detect small changes in the tissue/fluid ratio in a realistic head configuration. Methods Changes in the scattering parameters (S21) of an inductive coil resulting from injections of chicken blood in the 0–18 ml range into calf brain tissue in a human anatomical skull were measured over a 100–1,000 MHz frequency range. Results An algorithm that combines amplitude and phase results was found to detect changes in the tissue/fluid ratio with 90% accuracy. An algorithm that estimated the injected blood volume was found to have a 1–4 ml average error. This demonstrates the possibility of the inductive coil-based device to possess a practical ability to detect a change in the tissue/fluid ratio in the head. Significance This study is an important step towards the goal of building an inexpensive and safe device that can detect an early brain hemorrhagic stroke.

scholarly journals Polarization-Independent Ultra-Wideband Metamaterial Absorber for Solar Harvesting at Infrared Regime

Materials ◽  
2020 ◽  
Vol 13 (11) ◽  
pp. 2560 ◽  
Author(s):  
Asraful Alam ◽  
Sikder Sunbeam Islam ◽  
Md. Hobaibul Islam ◽  
Ali F. Almutairi ◽  
Mohammad Tariqul Islam
Keyword(s):  
Solar Spectrum ◽  
Equivalent Circuit Model ◽  
Metamaterial Absorber ◽  
Simulation Software ◽  
Unit Cell ◽  
Ultra Wideband ◽  
Scattering Parameters ◽  
Frequency Range ◽  
Relative Bandwidth ◽  
Polarization Insensitive

This paper presents an ultra-wideband metamaterial absorber for solar harvesting in the infrared regime (220–360 THz) of the solar spectrum. The proposed absorber consists of square-shaped copper patches of different sizes imposed on a GaAs (Gallium arsenide) substrate. The design and simulation of the unit cell are performed with finite integration technique (FIT)-based simulation software. Scattering parameters are retrieved during the simulation process. The constructed design offers absorbance above 90% within a 37.89% relative bandwidth and 99.99% absorption over a vast portion of the investigated frequency range. An equivalent circuit model is presented to endorse the validity of the proposed structure. The calculated result strongly agrees with the simulated result. Symmetrical construction of the proposed unit cell reports an angular insensitivity up to a 35° oblique incidence. Post-processed simulation data confirm that the design is polarization-insensitive.

scholarly journals Sub-THz Characterisation of Monolayer Graphene

2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
Ehsan Dadrasnia ◽  
Sujitha Puthukodan ◽  
Vinod V. K. Thalakkatukalathil ◽  
Horacio Lamela ◽  
Guillaume Ducournau ◽  
...  
Keyword(s):  
Continuous Wave ◽  
Dynamic Range ◽  
Monolayer Graphene ◽  
Network Analyzer ◽  
Electrical Characteristics ◽  
Scattering Parameters ◽  
Frequency Range ◽  
Terahertz Time Domain Spectroscopy ◽  
Wave Measurement ◽  
Direct Measurements

We explore the optical and electrical characteristics of monolayer graphene by using pulsed optoelectronic terahertz time-domain spectroscopy in the frequency range of 325–500 GHz based on fast direct measurements of phase and amplitude. We also show that these parameters can, however, be measured with higher resolution using a free space continuous wave measurement technique associated with a vector network analyzer that offers a good dynamic range. All the scattering parameters (both magnitude and phase) are measured simultaneously. The Nicholson-Ross-Weir method is implemented to extract the monolayer graphene parameters at the aforementioned frequency range.

scholarly journals Classification of skin phenotypes caused by diabetes mellitus using complex scattering parameters in the millimeter-wave frequency range

2017 ◽  
Vol 7 (1) ◽  
Author(s):  
Fabian Dornuf ◽  
Pedro Martín-Mateos ◽  
Blanca Duarte ◽  
Bernhard Hils ◽  
Oscar Elias Bonilla-Manrique ◽  
...  
Keyword(s):  
Diabetes Mellitus ◽  
Millimeter Wave ◽  
Wave Frequency ◽  
Scattering Parameters ◽  
Frequency Range

Modeling of dielectric relaxation in clays at negative and positive temperatures

2021 ◽  
Vol 64 (1) ◽  
pp. 58-63
Author(s):  
A.V. Repin ◽  
◽  
O.V. Rodionova ◽  
E.S. Kroshka ◽  
◽  
...  
Keyword(s):  
Experimental Data ◽  
Dielectric Constant ◽  
Relaxation Process ◽  
Bound Water ◽  
Complex Dielectric Constant ◽  
Distilled Water ◽  
Frequency Range ◽  
Water Ice ◽  
Free And Bound Water ◽  
The Relationship

Experimental data on measuring the complex dielectric constant (CDP) of clays with full moistening with distilled water in the frequency range from 1 kHz to 8.5 GHz at temperatures from -15 to +25 °C are presented. The modeling of the dependences of is carried out by a multirelaxation model that takes into account the relaxation of free and bound water, as well as relaxation at the bound water - mineral and bound water - air boundaries. It is shown that at temperatures below -5 °C, a relaxation process appears in the CDP spectrum due to polarization at the bound water - ice or ice - mineral interface. The relationship between the parameters of this relaxation process and the petrophysical characteristics of the rock is found.

scholarly journals Traceable calibration of a horizontally polarised reference antenna with omnidirectional pattern at VHF frequencies for ILS field strength validation

2013 ◽  
Vol 11 ◽  
pp. 7-14
Author(s):  
T. Schrader ◽  
T. Kleine-Ostmann ◽  
J. Bredemeyer
Keyword(s):  
Field Strength ◽  
Uncertainty Budget ◽  
Antenna Gain ◽  
Practical Application ◽  
Scattering Parameters ◽  
Frequency Range ◽  
Antenna Factor ◽  
Calibration Setup ◽  
Validation Tool ◽  
Traceable Calibration

Abstract. We present a traceable calibration of a specially designed horizontally polarised reference antenna with an omnidirectional pattern in the E-plane for the frequency range between 105 MHz and 120 MHz. This antenna is used as a validation tool for absolute field strength measurements at the localizer transmitter of an instrument landing system (ILS) at airports and is carried by a helicopter. We investigate whether we can treat it as a dipole-like antenna in the calibration setup despite its disk-shape body. We also investigate the suitability of an anechoic chamber for antenna calibration though it was not designed for that purpose. The measurements are based on scattering parameters (S-parameters) which we apply in the 3-antenna-method (TAM or 3-AM) to obtain the antenna gain and the antenna factor, respectively. An uncertainty budget for the antenna gain calibration is derived. We also report on the first practical application of the calibrated reference antenna.

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