731 |
A Study of Adobe Wall Moisture Profiles and the Resulting Effects on Matched Illumination Waveforms in Through-The-Wall Radar ApplicationsPrice, Steven Ryan 14 August 2015 (has links)
In this dissertation, methods utilizing matched illumination theory to optimally design waveforms for enhanced target detection and identification in the context of through-the-wall radar (TWR) are explored. The accuracy of assumptions made in the waveform design process is evaluated through simulation. Additionally, the moisture profile of an adobe wall is investigated, and it is shown that the moisture profile of the wall will introduce significant variations in the matched illumination waveforms and subsequently, affect the resulting ability of the radar system to correctly identify and detect a target behind the wall. Experimental measurements of adobe wall moisture and corresponding dielectric properties confirms the need for accurate moisture profile information when designing radar waveforms which enhance signal-to-interference-plus-noise ratio (SINR) through use of matched illumination waveforms on the wall/target scenario. Furthermore, an evaluation of the ability to produce an optimal, matched illumination waveform for transmission using simple, common radar systems is undertaken and radar performance is evaluated.
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Cavity perturbation technique for measurement of dielectric properties of some agri-food materials.Venkatesh, Meda S. January 1996 (has links)
No description available.
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733 |
Integrated dual frequency permittivity analyzer using cavity perturbation conceptMeda, Venkatesh. January 2002 (has links)
No description available.
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734 |
Radio-Frequency thermal treatments for agri-food productsOrsat, Valérie. January 1999 (has links)
No description available.
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735 |
Termination and passivation of Silicon Carbide Devices.Wolborski, Maciej January 2005 (has links)
Silicon carbide rectifiers are commercially available since 2001, and MESFET switches are expected to enter the market within a year. Moreover, three inch SiC wafers can be purchased nowadays without critical defects for the device performance and four inch substrate wafers are announced for the year 2005. Despite this tremendous development in SiC technology, the reliability issues like device degradation or high channel mobility still remain to be solved. This thesis focuses on SiC surface passivation and termination, a topic which is very important for the utilisation of the full potential of this semiconductor. Three dielectrics with high dielectric constants, Al2O3, AlN and TiO2, were deposited on SiC with different techniques. The structural and electrical properties of the dielectrics were measured and the best insulating layers were then deposited on fully processed and well characterised 1.2 kV 4H SiC PiN diodes. For the best Al2O3 layers, the leakage current was reduced to half its value and the breakdown voltage was extended by 0.5 kV, reaching 1.6 kV, compared to non passivated devices. As important as the proper choice of dielectric material is a proper surface preparation prior to deposition of the insulator. In the thesis two surface treatments were tested, a standard HF termination used in silicon technology and an exposure to UV light from a mercury lamp. The second technique is highly interesting since a substantial improvement was observed when UV light was used prior to the dielectric deposition. Moreover, UV light stabilized the surface and reduced the leakage current by a factor of 100 for SiC devices after 10 Mrad γ ray exposition. The experiments indicate also that the measured leakage currents of the order of pA are dominated by surface leakage. / QC 20110114
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Fabrications and optical properties of loss-reduced silicon metasurfaces for luminescence enhancement / 発光増強のための損失低減シリコンメタサーフェスの作製と光学特性LIU, LIBEI 23 March 2023 (has links)
京都大学 / 新制・課程博士 / 博士(工学) / 甲第24626号 / 工博第5132号 / 新制||工||1981(附属図書館) / 京都大学大学院工学研究科材料化学専攻 / (主査)教授 田中 勝久, 教授 三浦 清貴, 教授 藤田 晃司 / 学位規則第4条第1項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DGAM
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The Design, Fabrication, and Applications of 3D Printed CapacitorsPhillips, Brandon Andrew January 2021 (has links)
No description available.
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738 |
DESIGN AND IMPLEMENTATION OF MICROSTRIP MONOPOLE AND DIELECTRIC RESONATOR ANTENNAS FOR ULTRA WIDEBAND APPLICATIONSMorsy, Mohamed Mostafa 01 December 2010 (has links)
Ultra wide-band (UWB) technology is considered one of the very promising wireless technologies in the new millennium. This increases the demand on designing UWB antennas that meet the requirements of different UWB systems. In this dissertation, different UWB antennas are proposed such as an antenna that covers almost the entire UWB bandwidth, 3.5-11 GHz, as defined by the federal communication commission (FCC). This antenna has a size of 50×40×1.5mm3. Miniaturized worldwide UWB antennas are also introduced. Miniaturized worldwide UWB antennas that have compact sizes of (30×20×1.5) mm3, and (15×15×1.5) mm3 are also investigated. The designed worldwide UWB antennas cover the UWB spectrums defined by the electronic communication committee (ECC), 6-8.5 GHz, and the common worldwide UWB spectrum, 7.4-9 GHz. A system consisting of two identical antennas (transmitter and receiver) is built in the Antennas and Propagation Lab at Southern Illinois University Carbondale (SIUC) to test the coupling properties between every two identical antennas. The performance of that system is analyzed under different ii conditions to guarantee that the transmitted signal will be correctly recovered at the receiver end. The designed UWB antennas can be used in many short range applications such as wireless USB. Wireless USB is used in PCs, printers, scanners, laptops, MP3 players, hard disks and flash drives. A new technique is introduced to widen the impedance bandwidth of dielectric resonator antennas (DRAs). DRA features compactness, low losses, and wideband antennas. Different compact UWB DRAs are investigated in this dissertation. The designed DRAs cover a wide range of frequency bands such as, 6.17-24GHz, 4.23-13.51GHz, and 4.5-13.6GHz. The designed DRAs have compact sizes of 1×1×1.5cm3, 0.9×0.9×1.32cm3, 0.6×0.6×1cm3, and 0.6×0.6×0.9cm3; and cover the following frequency bands 4.22-13.51GHz, 4.5-13.6GHz, 6.1-23.75GHz, and 6.68-26.7GHz; respectively. The proposed DRAs may be used for applications in the X, Ku and K bands such as military radars and unmanned airborne vehicles (UAV).
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739 |
Finite Element Analysis of EMI in a Multi-Conductor ConnectorZafaruddin, Mohammed 23 May 2013 (has links)
No description available.
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740 |
Transparent Tissues and Porous Thin Films: A Brillouin Light Scattering StudyBailey, Sheldon T. 21 May 2013 (has links)
No description available.
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