Search for dissertations about: "focal plane array"
Showing result 1 - 5 of 14 swedish dissertations containing the words focal plane array.
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1. Miniaturized Hard Waveguides in Multifunction Array Antennas
Abstract : Recent advances in technologies of wireless communications systems have led to an increasing desire for several antennas performing diverse functions at different frequencies to be integrated into a common radiating aperture. This gives rise to the so-called multifunction antenna, which affords the saving of scarce premium real estate and can alleviate problems arising from excessive antenna protrusions in aspects such as aerodynamics, aesthetics, and stealth capability in military applications. READ MORE
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2. On millimeter and submillimeter wave focal plane arrays implemented with MEMS waveguide switches
Abstract : This thesis presents research towards enabling micromachined millimeter and submillimeter wave focal plane arrays (FPAs). The FPAs operate under the following principle: a switch network consisting of microelectromechanical (MEMS) switches, integrated with micromachined waveguides, is used to feed an array of antenna elements, located in the focal plane of a high-gain quasi-optical system. READ MORE
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3. Digital Beamforming Focal Plane Arrays for Radio Astronomy and Space-Borne Passive Remote Sensing
Abstract : Dense Phased Array Feeds (PAFs) for reflector antennas have numerous advantages over traditional cluster feeds of horns in a one-horn-per-beam configuration, especially in RF-imaging applications which require multiple simultaneously formed and closely overlapping beams. However, the accurate analysis and design of such PAF systems represents a challenging problem, both from an EM-modeling and beamforming optimization point of view. READ MORE
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4. Frequency Selective Cold-Electron Bolometer Arrays
Abstract : This work presents the integration of the Cold-Electron Bolometer (CEB) in Frequency Selective Surface (FSS) based arrays targeting balloon-borne telescope missions with high incident power requirements (typically tens of pW). FSS are planar frequency sensitive structures typically consisting of repeating pattern of a simple motif like square, circle, etc. READ MORE
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5. Mm-wave Radio Astronomy Instrumentation for the Onsala Space Observatory and SEST
Abstract : The thesis presents work done in developing instrumentation for mm- and submm-wave radio astronomy. The work described is in several fields. The greater part of the thesis is concerned with sensitive heterodyne receivers and in particular the cryogenically cooled mixers. In paper A the SEST telescope and its observing system are described. READ MORE