Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 70 for “"metasurface"”.
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Deterministic Design of Metasurface Antennas
L'abstract è presente nell'allegato / the abstract is in the attachment
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Metasurface Implementation in Optic Fibers
… ανάλυση μίας διηλεκτρικής μεταεπιφάνειας (metasurface) για εκτροπή δέσμης στη τηλεπικοινωνιακή περιοχή μήκους κύματος 1.55 μm. Ξεκινώντας με αναδρομή στην στην ιστορία των μεταϋλικών, αναδεικνύεται η σημασία τους στη σύγχρονη μελέτη του τομέα της Οπτικής. Το θεωρητικό κομάτι της εργασίας …
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modeling and application of nonlinear metasurface
<p>A patterned metasurface can strongly scatter incident light, functioning as an extremely low-profile lens, filter, reflector or other optical devices. Nonlinear metasurfaces‒combine the properties of natural nonlinear medium with novel features such as negative refractive index, magneto-electric …
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Detectivity vs. Sensitivity: Non-Hermitian Metasurface Sensor
Detectivity is the most important performance metric of any sensor. Detectivity is limited by the sensitivity of a sensor when the probe significantly overwhelms the detector noise. But, when the probe is limited in its power budget, as in sensors on mobile platforms, high sensitivity does not …
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Ultrathin metasurface devices for phase and polarization control
… techniques. As 2D counterparts of metamaterials, metasurfaces, which are comprised of a single layer or a stack of several layers of 2D structures, can facilitate manufacturing process and manipulate light propagation in desirable manner. Metsurfaces are ultrathin and ultraflat, which has enabled …
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Multimode Ultrastrong Coupling with FW-BICs in THz Metasurface
… to microwave frequencies. A unit cell of the metasurface consisting of a 200 nm thick Al thin film that consists of the cavity-dipole system on a 150 µm thick quartz substrate. The cavity-dipole system consists of a cavity that is 280 µm x 30 µm and a ribbon that is 10 µm wide with its length …
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A Design Flow for Additively Manufactured 3D Metasurface Antennas
<p>Metasurface (MTS) antennas are complex arrays consisting of hundreds or thousands of individual elements that each exert their own influence on the performance of the antenna. Due to this, the process of designing and developing a MTS antenna can be intensive in terms of both the time to …
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Numerical Techniques for the Automated Design of Metasurface Antennas
L'abstract è presente nell'allegato / the abstract is in the attachment
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Dynamic Metasurface Grouping for IRS Optimization in Massive MIMO Communications
Intelligent Reflecting Surfaces (IRSs) grant the ability to control what was once consideredthe uncontrollable part of wireless communications, the channel. These smart signal mirrors show promise to significantly improve the effective signal-to-noise-ratio (SNR) of cell-users when the …
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Enhance of LCOS Phase Modulation in Visible Wavelength Range Based on Metasurface
This thesis explores the integration of metasurface with liquid crystal on silicon (LCOS) technology to enhance the phase modulation capability while reducing the thickness of the liquid crystal layer, addressing key challenges in high-performance holographic displays. LCOS devices are known for …
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Electrically Tunable Liquid Crystal–Metasurface Devices for Phase Modulation in Telecom Band
… the response and limits device performance. Metasurfaces introduce phase shifts with ultrathin structures, and when integrated with LC, they enable dynamic 2π modulation with reduced LC thickness, thereby improving response speed while maintaining a large phase modulation depth. Building on …
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Advancing 5G Coverage: Novel Methods for Metasurface Characterization and Leaky-Wave Antenna Reconfigurability
… to enhance 5G coverage through accurate metasurface (MS) characterization using incident field reconstruction and pattern reconfigurability in leaky wave antennas (LWAs). Metasurfaces offer potential coverage enhancement by signal manipulation. The incident field reconstruction method …
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Study of force discrimination on chiral molecules and particles by circular polarized light and metasurface enhanced field
… or from enhanced fields generated by a plasmonic metasurface. This topic was first motivated by the need of separating enantiomers mechanically. Now many works have been done by different groups. Inspired by these works, a general expression of force under an incident time-varying electromagnetic …
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Dynamic Metasurfaces for Advanced Applications
<p>To date metamaterials and metasurfaces have been studied for over 20 years. Throughout this time sophisticated understanding of their properties and capabilities has been developed, with many significant and exotic properties such as flat lenses, negative refraction, and perfect absorption. In …
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Directionally Sensitive Sensor Based on Acoustic Metamaterials
… broadband acoustic sources that uses an acoustic metasurface. The metasurface is comprised of a meandering channel of quarter-wave cavities and an array of equally spaced half-wave open through-cavities. A series of tests were conducted in Virginia Tech's Anechoic Wall-Jet Tunnel where …
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Polarization control and measurement with meta-optics
Metasurfaces are artificially engineered arrays of subwavelength phase-shifting elements which, if designed with explicit polarization dependence, provide a fascinating platform for new polarization optics. In this thesis, we present metasurface diffraction gratings designed to produce arbitrarily …
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Effect of Nanoparticle Shape on the Response of Broadband Metamaterial Absorbers in the Visible Spectrum
… in size of the gold nanoparticles in the top metasurface. However, in this work we show that variations in the shapes and the orientations of the gold nanoparticles in the top gold metasurface layer also contribute to the broadband response of these MIM structures. In order to quantify shape …
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Design of Ultra-wideband Reflectors
… second method, the reflector is designed as a metasurface. The TO method amounts to manipulating of electromagnetic waves using an appropriate set of material parameters such that the wave propagation inside the material behaves in a desired manner. We use TO as a means to design an …
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Reconfigurable Intelligent Metasurfaces for Wireless Communication and Sensing Applications
In recent years, metasurfaces have shown promising abilities to control and manipulate electromagnetic (EM) waves through modified surface boundary conditions. These surfaces are electrically thin and comprise an array of spatially varying sub-wavelength scattering elements (or meta-atoms). …
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