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 18 of 18 for “"28 GHz"”.
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Diffraction by Building Corners at 28 Ghz: Measurements and Modeling
This thesis presents the results of a 28 GHz continuous-wave (CW) diffraction measurement campaign in the Washington, DC area. It describes the measurement approach including information on equipment and testing methods. Also described are the various parameters that affected the diffraction loss. …
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Performance Comparison of Harmonically Tuned Power Amplifiers at 28 GHz in SiGe BiCMOS
… class-F and inverse class-F (class-F-1) at 28 GHz. The PAs have identical input networks: input matching, base DC feed, and base stabilizing networks. At the load side, there is a different load network for each PA. Class-AB PA load network has a single inductor with a parasitic capacitor to …
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A Study of Rough Surface Scattering Phenomena in the LMDS Band (28 GHz)
… phenomena were investigated in the LMDS band (28 GHz). We used the newly developed sampling swept time delay short pulse (SSTDSP) sounder to collect field data in certain locations on the Virginia Tech campus. The sounder collected the channel impulse response analog waveform, sampled, …
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Channel Impulse Response and Its Relationship to Bit Error Rate at 28 GHz
… high bandwidth wireless communication system at 28 GHz (Local Multipoint Distribution Service frequency). This system provides a large bandwidth radio link to a disaster zone up to 5 km away and puts Ethernet speeds and 802.11 accesses to users within hours. Because of the possible variability in …
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RF and GIS: Field Strength Prediction for Frequencies between 900 MHz and 28 GHz
… strength for frequencies between 902 MHz and 28 GHz. The model approximates diffraction using the knife-edge concept and equations proposed by Lee (1985). LOS pathways are calculated using the Bresenham algorithm and the corresponding elevations are obtained from a 30m DEM base map. The base …
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Pattern reconfigurable metamaterial antenna for 5G base station network
… bands i.e. millimetre-wave (MMW) band and sub-6 GHz band for beam deflection applications. The modified double square ring resonator (DSRR) and contiguous squares resonator (CSR) structures are investigated numerically and experimentally to provide low loss property at 76 GHz and around 28 GHz, …
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The dynamic behavior of rain attenuation on satellite communication links
… of communication satellites operating above 10 GHz has stimulated research into the effects of atmospheric rain and ice on the reception of these signals. This thesis examines the statistics of fade rate, fade duration, and interface intervals on 19 and 28 GHz communication links, at an …
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Adaptive Digital Predistortion with Applications for LMDS Systems
… obtained from laboratory measurements of a 28 GHz amplifier to determine the effect of several predistortion implementation options and to confirm the feasibility of the proposed architecture. The potential impact of this predistortion architecture on LMDS system design is considered. The …
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Coexistence of Wireless Systems for Spectrum Sharing
… 5G 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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System Performance of an Over-Water Propagation for an LMDS Link
… technologies. At a carrier frequency of about 28 GHz, the potential benefits of Local Multipoint Distribution Service (LMDS) will eventually outweigh those of its current competitors in the wired market. Since the rural communities will reap the most benefits from this technology due to its low …
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The radiation physics, mitigation approaches and design guidelines of high-speed connectors and cables analyzed with numerical modeling, analytical formulation and measurements
… cage connector in the frequency range of 4-28 GHz is analyzed with validated full-wave simulation model and analytical formulas. The radiation from the optical cage connector is suppressed with absorbing materials, and the coupling path in optical link is verified, together with the optical …
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Design of broad-band dual-polarized microstrip patch antennas with high port isolation for millimeter-wave 5G applications
… the next generation of 5G communications around 28 GHz. Dual polarization antennas are employed to increase the capacity of the allocated spectrum through frequency reuse. Techniques for improving the impedance bandwidth is one of the most researched areas of microstrip antenna technology. New …
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Millimeter-Wave and Sub-Terahertz Parametric Harmonic Generation
… bands. A frequency tripler is designed in the 28-GHz 5G band, using the topology of symmetric antiparallel pair of series varactors to achieve about 24-dB conversion loss (CL), −8-dBm maximum output power (POUT), and 18% relative bandwidth (BW). Two reconfigurable frequency multipliers (RFMs) …
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Propagation channel models for 5G mobile networks. Simulation and measurements of 5G propagation channel models for indoor and outdoor environments covering both LOS and NLOS Scenarios
… investigated at four different frequencies; 5.8 GHz, 26GHz, 28GHz and 60GHz for vertical polarized directional, omnidirectional and isotropic antennas patterns. The computed data achieved from the 3-D Shooting and Bouncing Ray (SBR) Wireless Insite based on the effect of frequency dependent …
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Design and Implementation of a Swept Time Delay Short Pulse (SSTDSP) Wireless Channel Sounder for LMDS
… fixed point high data rate applications in the 28 GHz LMDS band at a fraction of the cost and complexity of existing wideband channel sounders. The SSTDSP sounder monitors the behavior of the LMDS channel by sampling the impulse response of the channel in real time. This digitized impulse …
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Adaptive and Robust Multi-Gigabit Techniques Based MmWave Massive MU-MIMO Beamforming For 5G Wireless and Mobile Communications Systems. A Road Map for Simple and Robust Beamforming Scheme and Algorithms Based Wideband MmWave Massive MU-MIMO for 5G Wireless and Mobile Communications Systems
… of the four 5G candidate mmWave frequencies, 28 GHz, 39 GHz, 60 GHz, and 73 GHz, are investigated for indoor/outdoor propagation scenarios, including path loss models and multipath delay spread values. Results are compared to confirm that the received power and delay spread is decreased with …
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Millimeter-Wave Harmonically-Tuned Silicon Power Amplifiers for High Efficiency
… performances reported so far: PAE= 50% @ 24 GHz, PAE = 43% @ 41 GHz, and PAE = 23% @ 94 GHz. The design methodology and detailed analysis of the proposed load networks presented and verified with implementation and measured results.
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Non-linear analysis and optimization techniques for sub-millimiter and therahertz circuits and systems, implemented for imaging and communication systems
… elevada de la señal autónoma con f0 = 60 GHz, siendo este el cuarto armónico, con frecuencia 4f0 = 240 GHz. En régimen sincronizado, el oscilador incrementa su funcionalidad y se convierte en un desfasador variable de rango amplio y continuo, controlado electrónicamente. Como la señal de …