A5077254410- Microwave and Dielectric Measurement Techniques
- Microwave Imaging and Scattering Analysis
- Electromagnetic Scattering and Analysis
- Advanced Antenna and Metasurface Technologies
- Soil Moisture and Remote Sensing
- Geophysical Methods and Applications
- Antenna Design and Analysis
- Microwave Engineering and Waveguides
- Electromagnetic Compatibility and Measurements
- Advanced MIMO Systems Optimization
- Advanced MRI Techniques and Applications
- Planetary Science and Exploration
- Photonic Crystals and Applications
- Metamaterials and Metasurfaces Applications
- Acoustic Wave Resonator Technologies
- Millimeter-Wave Propagation and Modeling
- Wireless Body Area Networks
- Advanced NMR Techniques and Applications
- Astro and Planetary Science
- Non-Destructive Testing Techniques
- Antenna Design and Optimization
- Material Properties and Processing
- Electron Spin Resonance Studies
- Microwave Dielectric Ceramics Synthesis
- Numerical methods in inverse problems
Centrale Marseille
2015-2024
Institut Fresnel
2015-2024
Centre National de la Recherche Scientifique
2015-2024
Aix-Marseille Université
2013-2023
Centre Interdisciplinaire de Nanoscience de Marseille
2023
École Centrale Paris
2010
Orange (France)
2008
Cezanne (Italy)
2007
Laboratoire d'Optique Appliquée
1997-1999
In this paper we present the first results on emission in metamaterial. We show how specific properties of metallic composite material can modify an embedded source. that under proper conditions energy radiated by a source slab metamaterial will be concentrated narrow cone surrounding media. An experimental demonstration effect is given microwave domain, and constructed antenna has directivity equivalent to best reported with photonic-crystal-based antennas but using completely different...
In the present paper, experimental set-up of Institut Fresnel used to measure scattered fields different elongated objects is precisely described. Since special issue on ‘Testing inversion algorithms against data’, modifications this system, outlined here, have mostly been done improve synchronization apparatuses and precision our measurements. Due a large number requests from inverse problem community, it has decided add new measurements Fresnel's database. All targets presented here are...
We report the design of a directive antenna using electromagnetic resonances Fabry-Perot cavity. The cavity is made ground plane and single metallic grid. resonance excited by patch placed in at vicinity plane. two remarkable features antennas are, first, that they are very thin second only one excitation point needed. A directivity about 600 measured f=14.80 GHz which to our knowledge highest directivities reported for an resonances.
In this paper, the experimental setup and improvements required to obtain further measurements for third opus of Fresnel Database are presented. The most original feature those new datasets is fact that they were obtained with three-dimensional targets instead two-dimensional ones used in two previous opuses. performed all around under test collect enough information about objects be able perform inversion on their scattered fields. As small comparison wavelength, challenge here was extract...
Ultrahigh-field (UHF) magnetic resonance imaging (MRI) systems are getting a lot of attention as they ensure high intrinsic signal-to-noise ratio resulting in higher spatial and temporal resolutions well better contrast. This promises improved clinical results with regard to morphological functional metabolic capabilities. Traditionally, MRI relies on volume coils (birdcage) able deliver homogeneous radio frequency field exciting the nuclei spin. However, this strategy is hindered at UHF...
Reconstructions of two dimensional dielectric or conducting objects from multi-frequency experimental data are considered in the present paper. Two different iterative methods used for solving inverse scattering problem. The first one is based on a boundary integral formalism and retrieves boundaries complex permittivities unknown homogeneous scatterers. For this method initial guesses derived decomposition time reversal operator (DORT) combined with low frequency approximation. second...
We present a 3D spherical bistatic experimental setup developed in the anechoic chamber of Institut Fresnel Marseille, France, for scattering measurements targets microwave domain, both copolarization and cross‐polarization. first describe geometry setup, measurement protocol, calibration process. The results obtained different metallic dielectric are then compared to numerical simulations, computed either using coupled dipole method or Mie theory. These comparisons used validate algorithms...
Abstract In this article, we present a very simple toolkit for permittivity and permeability measurement in the microwave region real time. This kit contains coaxial cell dedicated software compatible with any Vector Network Analyzer (VNA) reconstruction of data. The customizing design depends on applications material forms. overall cells reconstructs directly time from S ‐parameters measured. Nicolson & Ross‐Weir algorithm is using after de‐embedding process done by modeling our an...
Measurement accuracy is a key point when dealing with microwave scattering measurements of 3‐D targets. This even more drastic the targets are small compared to wavelength. In order be able fully exploit spherical multistatic setup and measure pattern from in copolarization cross polarization, detailed analysis experimental errors that disturb scattered field was carried out, measurement methodology derived. Such performed anechoic chamber Institut Fresnel Marseille, France. So far, our...
Abstract We describe two experiments demonstrating that a cylindrical cloak formerly introduced for linear surface liquid waves works equally well sound and electromagnetic waves. This structured behaves like an acoustic with effective anisotropic density permittivity, respectively. Measured forward scattering pressure magnetic fields are in good agreement provide first evidence of broadband cloaking. Microwave 3D wave simulations further confirm reduced backscattering when rectangular...
Abstract In this paper, we propose, design and test a new dual-nuclei RF-coil inspired by wire metamaterial structures. The coil operates as result of resonant excitation hybridized eigenmodes in multimode flat periodic structures comprising several coupled thin metal strips. It was shown that the field distribution (i.e. penetration depth) can be controlled independently at two different Larmor frequencies selecting proper eigenmode each mutually orthogonal proposed requires no lumped...
The Rosetta spacecraft made a rendezvous with comet 67P/Churyumov-Gerasimenko (67P) in 2014 August, soon after the Philae module landed on small lobe of nucleus November 12. CONSERT instrument, onboard and Philae, sounded upper part interior 67P radiowaves at 90 MHz determined an average real permittivity (hereafter ε΄) equal to about 1.27. SESAME-PP near-surface 400–800 Hz range lower limit ε΄ 2.45. We use semi-empirical formula obtained from measurements performed laboratory 243 K water...
The authors propose a method to correct for drift errors which occur when performing three-dimensional scattering field measurements. This has the advantages of being fast, without loss information and with no need priori on scatterer. It is based properties limited spatial bandwidth scattered field.
We present an extensive experimental study of microwave scattering by a fully characterized complex aggregate. measured the full amplitude matrix (amplitude and phase four elements) for wide range configurations. The presented results are special interest to light community. Our experiments offer possibility validate numerical methods against experiments, since geometrical dielectric properties target known high degree precision, situation difficult attain in optical regime. analyze detail...
Purpose Perovskites are greatly used nowadays in many technological applications because of their high permittivity, more specifically the form aqueous solutions, for MRI dielectric shimming. In this study, full characterizations highly concentrated CaTiO 3 /BaTiO water mixtures were carried out and new permittivity maxima was reached. Methods Permittivity measurements done on solutions from 0%v/v to dry powder. The dependence with pressure investigated. Scanning electron microscopy images...
The internal properties of porous and icy bodies in the solar system can be investigated by ground-penetrating radars (GPRs), like COmet Nucleus Sounding Experiment Radiowave Transmission instrument on board Rosetta spacecraft which has sounded interior nucleus comet 67P/Churyumov-Gerasimenko. Accurate constraints permittivity media are needed for interpretation data. We report novel measurements performed water ice samples mixtures with porosities 31–91% range. have been between 50 MHz 2...
We investigate dynamic effective anisotropy in photonic crystals (PCs) through a combination of an medium theory, which is high-frequency homogenization (HFH) method explicitly developed to operate for short waves, as well numerical simulations and microwave experiments. The HFH yields accurate predictions the anisotropic properties periodic structures when wavelength comparable order pitch array; specifically, we square array 2 cm consisting dielectric rods radius $0.5$ refractive index...
Aims. Permittivity measurements on porous samples of volcanic origin have been performed in the 0.05–190 GHz range under laboratory conditions support Rosetta mission to comet 67P/Churyumov–Gerasimenko, specifically with MIRO radiometric experiment and CONSERT radar experiment.
This paper presents methodologies and equipment for SI-traceable inline measurements of water content (a critical quality parameter) in solid biofuels. Inline measurement systems are commonly used at CHP plants, providing continuous real-time data. However, the accuracy these is most cases unsatisfactory, mainly because not calibrated representatively relevant material, until now, calibrations traceable to SI system have been available. To provide reliable accurate data, new procedures...