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Separated Microstrip Antenna for Satellite Simulators
No full textThe Microstrip transmitter antenna is designed for the uplink at 14.25 GHz and receiver antenna is designed for the downlink at 11.45 GHz. The transmitter and receiver antennas are designed on a single substrate with microstrip transmission feedline on two sides for each frequency band. Quarter-wavelength structure is used for matching. Simulation results reveal a broadband structure for reflection, with a gain of 7 dB and high efficiency
Scalable and efficient photonic designs using disordered metamaterial nanounits
No full textWe explored the material and architecture requirements for the realization of light perfect absorption using these metamaterial designs from ultraviolet (UV) to far-infrared (FIR) wavelength regimes. This, in turn, opens up the opportunity of the practical application of these perfect absorbers in large scale dimensions. We adopted these lithography-free techniques in many applications including photoelectrochemical water splitting, photodetection, light emission, sensing, filtering and thermal camouflage
Dragging and amplifying light with space-time metamaterials
No full textIn this talk I will consider space-time metamaterials of travelling-wave type and introduce the theory of homogenisation of these modulated media
Wideband metamaterial absorber: from concept to naval applications
No full textThis presentation focuses on the results obtained during the two projects SAFAS and SAFASNAV, which highlight the evolution from the concept of broadband absorber with metamaterials to a realization of this concept in structural material for naval application. The French Ministry of Defense (DGA), through the National Research Agency (ANR) and the Astrid and Astrid Maturation programs, funded the research that led to these results. The simulation results were obtained using GENCI's HPC resources (Grant c2016107558)
Graphene loaded 1 x 3 MIMO Terahertz Wideband Antenna with High Isolation for Medical and Short Indoor Applications
No full textIn this paper, novel approach tri – element Multiple – Input Multiple – Output (MIMO) terahertz (THz) antenna is designed to cover wide band characteristics from 2.44 – 3.09THz for medical, short – indoor and THz applications. The proposed MIMO antenna is designed on quartz glass dielectric material within compact size of 120µm x 60µm, offers of wide impedance bandwidth (IBW) of 0.65THz, isolation less than -20dB, peak gain 6.82dB and high radiation efficiency of 92 – 98%. Furthermore, in order to meet the high date transmission rate and channel capacity performance of MIMO antenna, MIMO antenna parameters envelope correlation coefficient (ECC < 0.07), diversity gain (DG ~ 10dB), total active reflection coefficient (TARC < 0.65), channel capacity loss (CCL < 0.75bits/sec/Hz) and mean effective gain (-4dB < MEG < -12dB) are investigated and which are within acceptable limits
Phonon-plasmon interaction in film-coupled metallic nanoparticles mediated by surface acoustic waves
No full textWe demonstrate by numerical analysis enhanced optomechanical interaction in a film-coupled gold nanoridges or pillars mediated by surface acoustic waves. The nanoparticles are placed atop a multilayer structure consisting of a thin dielectric spacer covering a gold film layer on a silicon dioxide/or silicon substrate. The design supports both localized surface plasmons (infrared range) confined under the nanoparticles and elastic phonons (sub-GHz) localized in the latters. Phonon-plasmon coupling is evaluated from the shift in the plasmon eigenfrequency
A fast hybrid approach to model roughness effects for 2D the tropospheric maritime long-range propagation
No full textThis paper studies the long-range tropospheric electromagnetic wave propagation over the sea. An asymptotic model based on the parabolic wave equation is considered. This latter is solved using a fast and memory-efficient wavelet-based method. The roughness effects of the sea are introduced through a hybrid approach. Numerical experiments (in X-band) are provided to highlight the advantages of the wavelet-based method in the context of maritime propagation
Design and optimization of holographic nonlinear metasurfaces
No full textWe present the design and optimization of all-dielectric nonlinear metasurfaces using a simple sampling method combined with Monte Carlo simulation and demonstrate that the use of sophisticated optimization methods is not necessary. We apply this approach for the optimization of metasurface composed of silicon disks, which operates as a third harmonic beam deflector at a defined angle. Our results demonstrate a significant enhancement of radiated third harmonic intensity in the first diffraction order compared to that reported in literature
Silicon Metasurface for Heat-Light Conversion
No full textA perfect absorber (PA) is a key device for low-carbon society in future since PA mutually converts energy between heat and light. In this talk, I talk about all-dielectric PSs based on Si metasurfaces. In contrast to conventional plasmonic PAs, they are designed in different way by degenerate critical coupling (DCC) for visible and infrared region. We propose various novel structures of a Mie resonator supporting not only electric and magnetic dipoles but also quadrupoles to achieve DCC condition
Electromagnetic and Geophysical models to estimate wind speed from Sentinel 1 radar images - C band
No full textSAR (Synthetic Aperture Radar) systems are commonly used to observe the globe, and in particular the sea surface, since they can offer high spatial resolution data. To exploit SAR data, a description of the relationship between electromagnetic backscatter and the sea surface is essential. Thus, it is possible to use empirical (geophysical) or EM models. In this paper, we investigated and presented models for sea surface radar backscatter calculations and then used to estimate wind speed from Sentinel-1 images