Search for dissertations about: "near-field"

Showing result 16 - 20 of 91 swedish dissertations containing the word near-field.

2. 16. Design of Functional Structures and Measurement Techniques for Electromagnetic Waves

   Author : Johan Lundgren; Teoretisk elektroteknik; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; functional structures; frequency selective structures; polarization selectivity; metasurface; near-field measurements; antenna measurements; scattering measurement; power density; random media;

   Abstract : Electromagnetic fields exist all around us. Through evolution, nature has developed tools to interact and use these fields, where our eyes are a spectacular example. Humans have a long history of developing structures and objects of their own to alter and interact with these fields. READ MORE

4. 17. Controlled Source Radiomagnetotelluric (CSRMT) Applications in Environmental and Resource Exploration

   Author : Nazli Ismail; Laust Pedersen; Bulent Tezkan; Uppsala universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; Magnetotelluric; radio magnetotelluric; controlled-source tensor magnetotelluric; plane wave; near surface geophysics; sediment; fracture zone; inversion; forward modelling; near field effect; two-dimensional model; three-dimensional model; resolution; Geophysics; Geofysik; Earth Sciences with Specialization Environmental Analysis; geovetenskap med inriktning mot miljöanalys; Hydrology; hydrologi; mineralogi; petrologi och tektonik; Mineral Chemistry; Petrology and Tectonics;

   Abstract : An integrated use of radio magnetotelluric (RMT) and controlled source tensor magnetotelluric (CSTMT) measurements, the so-called CSRMT method, has been employed in environmental and resource exploration studies. A number of case histories, including a groundwater investigation in glacial deposits, a study of fracture zones for geotechnical purposes and a mining exploration study of a copper deposit, are presented in this thesis in order to illustrate the usefulness and capability of the CSRMT method. READ MORE

5. 18. Retrieval of equivalent currents by the use of an integral representation and the extinction theorem --- radome applications

   Author : Kristin Persson; Institutionen för elektro- och informationsteknik; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; extinction theorem; inverse source problem; integral representation; radome diagnosis; near-field transformation;

   Abstract : The aim of this thesis is to solve an inverse source problem. The approach is based on an integral representation together with the extinction theorem. Both a scalar and a full-wave integral representation are implemented and solved by a Method of Moment procedure. READ MORE

6. 19. Impact of carrier localization on recombination in InGaN quantum wells with nonbasal crystallographic orientations

   Author : Ruslan Ivanov; Saulius Marcinkevičius; Nicolas Grandjean; KTH; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; InGaN; quantum well; semipolar; nonpolar; near-field microscopy; carrier localization; carrier transport; optical polarization; Fysik; Physics;

   Abstract : The modern InGaN technology demonstrates high efficiencies only in the blue spectral region and low current operation modes. The growth of InGaN quantum wells (QWs) on nonbasal crystallographic planes (NBP) has potential to deliver high-power blue and green light emitting diodes and lasers. READ MORE

7. 20. Optical properties of GaN and InGaN studied by time- and spatially-resolved spectroscopy

   Author : Tomas Uždavinys; Saulius Marcinkevičius; Audrius Alkauskas; KTH; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; Gallium nitride; InGaN; near-field microscopy; photoexcited carrier dynamics; intervalley energy; Fe centers; In incorporation; Physics; Fysik;

   Abstract : The past decade has seen rapid expansion in the use of group III-nitride based devices. White InGaN LEDs are substituting incandescent light bulbs, space satellite industry adopting ion-radiation-resistant GaN transistors, and AlGaN deep UV LEDs are increasingly being used for water disinfection and air purification. READ MORE