Sökning: "metasurface"

Visar resultat 6 - 10 av 10 avhandlingar innehållade ordet metasurface.

1. 6. Nanostructured electromagnetic metasurfaces at optical frequencies

   Författare :Nils Odebo Länk; Chalmers tekniska högskola; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; high-index nanophotonics; colloidal lithography; metasurfaces; geometric resonances; nanostructures; plasmonics;

   Sammanfattning : Electromagnetic metasurfaces are broadly defined as optically thin layersthat are structured on the subwavelength scale. In general, metasurfacesthus consist of nanoparticles, or other kinds of ”meta-atom”, arranged insome pattern where both the individual particle sizes and the inter-particledistances are much smaller than the wavelength. LÄS MER

3. 7. High Frequency Microwave and Antenna Devices based on Transformation Optics and Glide-Symmetric Metasurfaces

   Författare :Mahsa Ebrahimpouri; Oscar Quevedo-Teruel; Nader Engheta; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Glide Symmetry; Transformation Optics; Lens Antennas; High Frequency; Microwave Devices; Electrical Engineering; Elektro- och systemteknik;

   Sammanfattning : The new generation of wireless communication networks intends to support data rate of Gbit/s. One solution to make it possible is to move upwards in frequency range to employ the unused spectrum in mm-wave frequencies. LÄS MER

4. 8. Conjugated polymers on plasmonic metasurfaces for high contrast electronic paper in color

   Författare :Oliver Olsson; Chalmers tekniska högskola; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; electrochromism; conjugated polymers; plasmonic electronic paper; PProDOT-Me2; reflective display;

   Sammanfattning : Electronic paper is the collective name of displays that, instead of emitting light, reflect the ambient light. These displays are known to have good readability in daylight and very low power consumption. However, there is a lack of electronic paper in color with high contrast and the ability to achieve video speed. LÄS MER

5. 9. Periodic Structures with Higher Symmetries: Analysis and Applications

   Författare :Fatemeh Ghasemifard; Martin Norgren; Oscar Quevedo-Teruel; Guido Valerio; Stefano Maci; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; periodic structures; higher symmetries; dispersion analysis; mode matching; generalized Floquet theorem; Electrical Engineering; Elektro- och systemteknik;

   Sammanfattning : In this thesis, periodic structures with higher symmetries are studied. Their wave propagation characteristics are investigated and their potential applications are discussed. Higher-symmetric periodic structures are described with an additional geometrical operation beyond a translation operator. LÄS MER

7. 10. Signal Processing Aspects of Massive MIMO and IRS-Aided Communications

   Författare :Özgecan Özdogan; Emil Björnson; Erik G. Larsson; Mari Kobayashi; Linköpings universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY;

   Sammanfattning : The data traffic in cellular networks has grown at an exponential pace for decades. This trend will most probably continue in the future, driven by new innovative applications. One of the key enablers of future cellular networks is the massive MIMO technology, and it has been started to be commercially deployed in many countries. LÄS MER