A5024360879- Advanced Antenna and Metasurface Technologies
- Metamaterials and Metasurfaces Applications
- Antenna Design and Analysis
- Electromagnetic Scattering and Analysis
- Antenna Design and Optimization
- Microwave Engineering and Waveguides
- Orbital Angular Momentum in Optics
- Advanced Wireless Network Optimization
- Energy Harvesting in Wireless Networks
- Millimeter-Wave Propagation and Modeling
- Advanced Surface Polishing Techniques
- Near-Field Optical Microscopy
- Advanced MIMO Systems Optimization
UCLouvain
2016-2024
Université d'Abomey-Calavi
2024
Institute of Information and Communication Technologies
2017
A new approach is presented for synthesizing modulated metasurface (MTS) antennas (MoMetAs) with arbitrary radiation patterns, assumed to be given in amplitude, phase, and polarization. The MTS defined on a circular domain represented as continuous sheet transition impedance boundary condition (IBC) the top of grounded substrate. proposed method relies an entire-domain discretization electric field integral equation (EFIE). Via dyadic Green's function substrate, desired pattern translated...
Multibeam and beam-scanning capabilities of metasurface (MTS) antennas using multiple feeds are investigated. The MTS synthesis is performed by direct inversion an electric field integral equation (EFIE) obtained after expanding the unknown equivalent impedance profile into Fourier-Bessel basis functions. Two approaches explored. first one assumes a priori discrete azimuthal symmetry in profile, so as to constrain solution subspace which automatically provides beams when illuminated with...
A family of orthogonal and entire-domain basis functions (named Fourier-Bessel) is proposed for the analysis circular modulated metasurface (MTS) antennas. In structures at hand, MTS accounted in electric field integral equation (EFIE) as a sheet transition impedance boundary condition on top grounded dielectric slab. The closed-form Hankel transform Fourier-Bessel (FBBFs) allows one to use spectral domain formulation method-of-moments (MoM) solution EFIE. Moreover, these are fully...
A recent synthesis paradigm for tailoring the far-field radiation of leaky wave (LW) radiating metasurface (MTS) antennas is reviewed and experimentally validated. The considered are realized with electrically small patches printed on a planar grounded dielectric slab. patch layer modeled as an impedance sheet whose spatial variation initially designed to provide desired LW effect from prespecified surface (SW) excitation.
An approach based on the method of moments and using a set stretched Fourier-Bessel basis functions (FBBFs) is presented for analysis elliptical domain metasurfaces (MTSs). This shape preferred to traditional circular domain, when better control aperture efficiency required. The proposed formulation makes use harmonic decomposition substrate dyadic Green's function efficiently compute reaction integrals. It shown that computation time associated with sheet impedance matrix calculation almost...
This paper presents two methods for the efficient evaluation of power balance in circular metasurface (MTS) antennas implementing arbitrary modulated surface impedances on a grounded dielectric slab. Both assume current homogenized MTS to be known. The first technique relies expansion with Fourier-Bessel basis functions (FBBF) and proceeds by integration Poynting vector closed surface. second method is based residue electric field spectrum at surface-wave (SW) pole, demonstrated using...
This article addresses the optimization of radiation pattern surface-wave (SW)-based metasurface (MTS) antennas. Those antennas are considered a promising alternative to parabolic reflectors and phased arrays due their extremely low profile ability provide high gain, shaped beams multibeams. However, synthesis with MTS is very challenging because single active control point need surface leaky waves through MTS. An accurate pattern, along sidelobe level requires full-wave modeling feeding...
A method based on the electric field integral equation is proposed for synthesizing planar metasurface (MTS) antennas built elliptical apertures. The MTS modeled with a modulated tensorial surface impedance. Entire-domain basis functions are used to discretize efficiently currents as well impedance, allowing quasi-direct computation of impedance from desired radiation pattern. corresponding combined near-field constant reactance derive MTS. obtained algorithm is, therefore, systematic and...
We present and discuss the synthesis of modulated metasurface (MTS) antennas capable radiating multiple beams at frequencies. The proposed technique is built on a recently developed integral equation formalism. Assuming that MTS can be homogenized over whole frequency band, sheet impedance describing accurately modeled w.r.t. frequency. This allows us to simultaneously establish systems equations standing for design different frequencies, possibly feed points, solve overall problem in...
A new architecture is provided for the efficient generation of shaped beams and multiple (in amplitude, phase, polarization), with leaky-wave (LW) metasurfaces (MTSs). Those antennas are usually fed by a surface-wave (SW) launcher, which evenly illuminates MTS versus azimuth, through cylindrical SW. When interest lies in generating pencil or particular types beams, required radiating aperture field (linked to Fourier transform desired radiation pattern) on almost azimuthally symmetric...
An efficient method of moments (MoM) scheme is presented for the analysis planar, possibly cascaded metasurfaces (MTSs) implementing high-impedance surfaces. The MTS can be designed on an arbitrarily shaped domain and accounted as a set electric sheet impedances. In proposed method, included in larger rectangular meshed with rooftop basis functions, resulting Toeplitz–block Toeplitz structure substrate impedance matrix, which enables fast Fourier transform (FFT)-based acceleration...
Metasurfaces are thin (2D) metamaterials designed for manipulating the dispersion properties of surface-waves (SWs) or reflection incident plane-waves. Thanks to sub-wavelength sizes patches used in implementation step, these surfaces can be described by a surface impedance boundary condition (IBC). In this paper, we investigate "Method Moments" (MoM) based analysis such with family entire-domain basis functions named "Fourier-Bessel" functions. The orthogonality property on disk allows us...
This paper provides new designs and realizations of leaky-wave (LW) metasurface (MTS) antennas fed at multiple points. The design technique is based on the direct integral-equation solution by Method Moments (MoM). unknown no longer current distribution, but impedance profile itself. method can be used to generate any shaped radiation pattern in amplitude, phase, polarization, provided that antenna area feeder illumination are consistent with shape desired pattern. algorithm also...
Two planar metasurface (MTS) antennas are designed to produce a pattern with optimal illumination in radar scenario, given the priori known path of targets. The extremely flat, thin, monopole feed integrated plane structure. serves as surface-wave (SW) launcher illuminating slab. excited SW progressively leaks after interacting MTS, forming radiation cover uniformly portion road scenario. realized patterns experimentally validated. MTSs then deployed frequency-modulated continuous wave...
The Method of Moments (MoM) is a powerful tool for computing the dispersion curves open and possibly lossy structures. However, brute-force computation associated to 2D periodic structure using MoM can be computationally intensive. One way accelerate reduce number unknowns used model Macro Basis Functions (MBFs). MBFs compute may seem counter-intuitive, since are usually obtained from response various excitations, while excitation-free homogeneous solution Maxwell's equations. In this paper,...
A low-profile, broadband <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$2\times 2$</tex> planar array constructed only of metal is proposed for space applications. The single element the capable generating circular polarization with a non-symmetrical (with respect to broadside) radiation pattern. Sequential rotation introduced at level correct asymmetry beam and improving purity. resulting antenna radiates broadside 12.5 dBi gain impedance...
Simulating the fine geometry of Metasurfaces (MTS) structures in a conventional way is difficult task requiring huge computational resources. On other hand, metallization can usually be modeled as (cascaded) impedance sheet(s) with modulation scale order operating wavelength. Such modeling, while homogenizing currents and fields on surface, accurate predicting far-field well near-field down to fraction wavelength from surface. However, analyzing an sheet lying grounded slab Method Moments...