Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 12 of 12 for “"70 GHz"”.
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Contributions towards a coherent chaotic oscillator at 100MHz and 70 GHz antennas for automotive radar applications.
… operating in the frequency range of 71-76 GHz. The array will be used to transmit the chaotic signal after it is up-converted. The requirements of the coherent chaotic oscillator in terms of delays and linearity are investigated using two simulation software: MATLAB and Advanced Design …
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Coexistence of Wireless Systems for Spectrum Sharing
… and Fixed Satellite Service (FSS) at 27.5-28.35 GHz (28 GHz); 5G and Fixed Service (FS) at 71-76 GHz (70 GHz); vehicular communications and Wi-Fi at 5.85-5.925 GHz (5.9 GHz); and mobile broadband communications and radar at 3.55-3.7 GHz (3.5 GHz). The results presented in each of the …
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Advancing Direct-Spun Carbon Nanotube Textiles, From Field Alignment to Innovative Applications
… (SE) in an ultra-wide bandwidth of 30 kHz to 70 GHz. Maximal SE of >120 dB was measured for a 30 g m-2 CNTM (<100 μm thickness) at 70 GHz. SE normalized by thickness (SE/t) reached a value of >20,000 dB cm-1 for an HCl oxidized CNT mat. Both attenuation values are the highest values for …
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High-Performance Gateless Iii-Nitride Microwave Switches
… for RF switching to frequencies not exceeding 6 GHz. In this dissertation, a new type of gateless microwave switch using capacitively-coupled contact (C3) is presented, which operates under very different mechanism than conventional ohmic HFET, and has lower loss, smaller OFF-state capacitance, …
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Multi-layer, Low-crosstalk Integrated Optical Switches
… leveraging the tri-layer platform to achieve >70 GHz bandwidth and sub-microsecond to nanosecond switching speeds. The thermo-optic device achieves crosstalk suppression of −33.2 to −50.8 dB and on-chip losses of 2.1–10.5 dB with micro-second scale switching time, while the electro-optic …
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Polymer waveguide based optical interconnects for high-speed on-board communications
… bandwidth-length products (BLPs) of at least 35 GHz×m, while the pulse broadening measurements reveal the actual BLPs to be in excess of 70 GHz×m under a 50 μm multimode-fibre (MMF) launch and 100 GHz×m for a restricted launch across a wide range of input offsets (>±10 μm). This shows the …
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Transimpedance Amplifier (TIA) Design for 400 Gb/s Optical Fiber Communications
… with transition frequencies exceeding 200 GHz and can improve optical receiver performance significantly. Increasing bandwidth to meet the target data rate is the most challenging task of TIA design especially in CMOS technology. Several CMOS TIA architectures have been published recently …
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Terahertz Spectroscopy of Topological Insulators and other 2-Dimensional Materials
… of tuning the plasmonic resonances by ~ 70 GHz. We further employ THz-TDS to map the conductivity of graphene film on different substrates such as germanium and sapphire. In chapter 3, we investigate Bi2Se3, a representative TI using THz spectroscopy and magnetotransport measurements. The …
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Abstimmbare Halbleiterlaser und schmalbandige Laserarrays mit verteilter lateraler Rückkopplung
… Breite beträgt hierbei typischerweise 50 bis 70 GHz. Für kleine Elementabstände koppeln die einzelnen Lichtwellen miteinander, was zu einer mit einem konventionellen DFB-Laser vergleichbaren Linienbreite führt. Während die ungekoppelten Arrays über ein gaußförmiges Fernfeld verfügen, ergibt …
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Broadband Terahertz Signal Generation and Radiation Based on Direct Digital-to-Impulse Radiating Arrays in Silicon
… mechanism results in numerous harmonics from GHz to THz. Based on the high timing accuracy of the radiated THz pulses in D2I, a novel trigger-based beamforming architecture is introduced that enables broadband pulse beamforming in which all frequency content is steered simultaneously. This is …
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Current Induced Magnetisation Dynamics in Ferromagnetic Nanowires
… The individual nanowires are excited by a 70 GHz Gaussian electric current pulse applied parallel to the nanowire axis. The calculated transient magnetisation distributions and power absorption spectra indicate predominately curling mode resonance for nanowire diameters ≥ 20 nm with …
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Integrated Wideband Self-Interference Cancellation Techniques for FDD and Full-Duplex Wireless Communication
… often referred to as the frequency band from 1-6GHz, has become increasingly crowded with only a limited amount of unused and unlicensed spectrum. This dissertation explores and implements, single-chip hardware front-end solutions which the specific aim to increase data rates for each single-user …