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Full-Text Articles in Engineering
Enhancing The Resolution Of Imaging Systems By Spatial Spectrum Manipulation, Wyatt Adams
Enhancing The Resolution Of Imaging Systems By Spatial Spectrum Manipulation, Wyatt Adams
Dissertations, Master's Theses and Master's Reports
Much research effort has been spent in the 21st century on superresolution imaging techniques, methods which can beat the diffraction limit. Subwavelength composite structures called ``metamaterials" had initially shown great promise in superresolution imaging applications in the early 2000s, owing to their potential for nearly arbitrary capabilities in controlling light. However, for optical frequencies they are often plagued by absorption and scattering losses which can decay or destroy their interesting properties. Similar issues limit the application of other superresolution devices operating as effective media, or metal films that can transfer waves with large momentum by supporting surface plasmon polaritons. In …
Electro-Optic Antenna Elements For Passive Phased Array Radar, Evan Gawron
Electro-Optic Antenna Elements For Passive Phased Array Radar, Evan Gawron
Dissertations, Master's Theses and Master's Reports
Passive phased antenna arrays are utilized in military and civilian radar systems to determine the received signal origination. Phased array placement for optimal reception is challenging due to the required supporting electronic hardware and the associated coaxial cabling that typically accompanies each antenna channel. Low noise amplifiers and frequency conversion hardware add size and complexity, limiting possible positions for phased array placement. Eliminating required phased array electronic subcomponents without sacrificing function would allow placement onto smaller agile platforms, such as unmanned systems and rapid deployment networks. Electro-optic (EO) antenna elements utilize an optical waveguide embedded between the antenna and ground …