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The Global ETD Search service is a free service for researchers
to find electronic theses and dissertations. This service is
provided by the
Networked Digital Library of Theses and Dissertations.
Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
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Showing 151 to 159 of 159 (0.017 seconds)| 151 |
Design and Heterogeneous Integration of Single and Dual Band Pulse Modulated Class E RF Power AmplifiersRashid, S M Shahriar January 2018 (has links)
No description available.
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Design of Multi-Beam Hybrid Digital Beamforming ReceiversMadishetty, Suresh January 2018 (has links)
No description available.
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Analysis & Design of Radio Frequency Wireless Communication Integrated Circuits with Nanoscale Double Gate MOSFETsLaha, Soumyasanta 25 August 2015 (has links)
No description available.
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Performance Assessment of a 77 GHz Automotive Radar for Various Obstacle Avoidance ApplicationKomarabathuni, Ravi V. 26 July 2011 (has links)
No description available.
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A 26 GHz Phase-Locked Loop Frequency Multiplier in 0.18-um CMOSCarr, John 25 April 2009 (has links)
This thesis presents the analysis, design and characterization of an integrated
high-frequency
phase-locked loop (PLL) frequency multiplier. The frequency multiplier is novel
in its use of a low multiplication factor of 4 and a fully differential topology
for rejection of common mode interference signals.
The PLL is composed of a voltage controlled oscillator (VCO), injection-locked
frequency divider (ILFD) for the first divide-by-two stage, a static
master-slave flip-flop (MSFF) divider for the second divide-by-two stage and
a Gilbert cell mixer phase detector (PD).
The circuit has been fabricated
using a standard CMOS 0.18-um process based on its relatively low cost and ready
availability. The PLL frequency multiplier
generates an output signal at 26 GHz and is the highest operational frequency PLL
in the technology node reported to date.
Time domain phase plane analysis
is used for prediction of PLL locking range based on initial conditions of
phase and frequency offsets.
Tracking range of the PLL is limited by the inherent narrow locking range of the ILFD,
and is confirmed via experimental results.
The performance benefits of the fully differential PLL are experimentally
confirmed by the injection of
differential- and common-mode interfering signals at the
VCO control lines. A comparison of the
common- and differential-mode modulation
indices reveals that a common mode rejection ratio (CMRR) of greater than 20 dB is
possible for carrier offset frequencies of less than 1 MHz.
Closed-loop frequency domain transfer functions are used for prediction of the PLL
phase noise response, with the PLL being dominated by the reference and
VCO phase noise contributions. Regions of dominant phase noise contributions
are presented and correlated to the overall PLL phase noise performance.
Experimental verifications display good agreement and confirm the usefulness of the
techniques for PLL performance prediction.
The PLL clock multiplier has an operational output frequency of 26.204 to 26.796 GHz
and a maximum
output frequency step of 16 MHz. Measured phase noise at 1 MHz offset from the
carrier is -103.9 dBc/Hz. The PLL clock multiplier core circuit
(VCO/ILFD/MSFF Divider/PD) consumes
186 mW of combined power from 2.8 and 4.3 V DC rails. / Thesis (Ph.D, Electrical & Computer Engineering) -- Queen's University, 2009-04-24 11:31:35.384
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Design of a low-power 60 GHz transceiver front-end and behavioral modeling and implementation of its key building blocks in 65 nm CMOSKraemer, Michael 03 December 2010 (has links) (PDF)
Worldwide regulations for short range communication devices allow the unlicensed use of several Gigahertz of bandwidth in the frequency band around 60 GHz. This 60GHz band is ideally suited for applications like very high data rate, energy-autonomous wireless sensor networks or Gbit/s multimedia links with low power constraints. Not long ago, radio interfaces that operate in the millimeter-wave frequency range could only be realized using expensive compound semiconductor technologies. Today, the latest sub-micron CMOS technologies can be used to design 60GHz radio frequency integrated circuits (RFICs) at very low cost in mass production. This thesis is part of an effort to realize a low power System in Package (SiP) including both the radio interface (with baseband and RF circuitry) and an antenna array to directly transmit and receive a 60GHz signal. The first part of this thesis deals with the design of the low power RF transceiver front-end for the radio interface. The key building blocks of this RF front-end (amplifiers, mixers and a voltage controlled oscillator (VCO)) are designed, realized and measured using the 65nm CMOS technology of ST Microelectronics. Full custom active and passive devices are developed and characterized for the use within these building blocks. An important step towards the full integration of the RF transceiver front-end is the assembly of these building blocks to form a basic receiver chip. Circuits with small chip size and low power consumption compared to the state of the art have been accomplished. The second part of this thesis concerns the development of behavioral models for the designed building blocks. These system level models are necessary to simulate the behavior of the entire SiP, which becomes too complex when using detailed circuit level models. In particular, a novel technique to model the transient, steady state and phase noise behavior of the VCO in the hardware description language VHDL-AMS is proposed and implemente d. The model uses a state space description to describe the dynamic behavior of the VCO. Its nonlinearity is approximated by artificial neural networks. A drastic reduction of simulation time with respect to the circuit level model has been achieved, while at the same time maintaining a very high level of accuracy.
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Photonic Techniques for Next-Generation Integrated Optical Networks Based on Ultra-Wideband Radio / Técnicas Fotónicas para Redes Ópticas Integradas de Próxima Generación Basadas en Radio de Banda Ultra AnchaBeltrán Ramírez, Marta 10 May 2012 (has links)
La presenta Tesis Doctoral encuentra su ámbito de aplicación en redes de acceso ópticas de fibra hasta el hogar o FTTH (del inglés fibre-to-the-home). Las redes FTTH han sido ampliamente desplegadas en todo el mundo y se prevé que evolucionen hasta arquitecturas de multiplexación por división en longitud de onda o WDM(dle inglés wavelength division multiplexing).
Conforme los requerimientos de capacidady ancho de banda por usuario para servicios de comunicación de banda ancha se incrementan continuamente, tecnologías tales como hybrid wireless-optical, radio de banda ultra ancha o UWB(del inglés ultra-wideband), y radio de onda milimétrica se están investigando como soluciones viables para proporcionar tasas de datos excediendo Gigabit por segundo por usuario. Las redes híbridas inalámbrico-óptico pueden proporcionar backhaul más simple y se prevé que desempeñen un papel importante en redes de acceso de próxima generación que requerirán despliegue flexible, alta capacidad, habilidad de ampliación, escalable en número de usuarios y demanda, y factible económicamente. Las técnicas radio sobre fibra combinadas con sistemas inalámbricos multigigabit que proporcionen capacidades comparables a sistemas de comunicaciones de fibra óptica se ve como una solución rápidamente desplegable y efectiva en coste para proporcionar acceso transparente cableado/inalámbrico integrado a servicios de banda ancha para el usuario final.
Los sistemas inalámbricos UWB y de onda milimétrica son capaces de proporcionar comunicaciones multigigabit. UWB en particular permite un uso eficiente del esprectro 3.1-10.6 GHz debido a sus características únicas de coexistencia y tiene madurez de mercado. Sin embargo, la tecnología UWB está restringida por regulación en todo el mundo. Esta restricción de regulación hace de gran interés a la radio de onda milimétrica en 60 GHz debido al aproximadamente 7 GHz de ancho de banda regulado consistentemente en todo el mundo, sin restricciones de coexistencia. / Beltrán Ramírez, M. (2012). Photonic Techniques for Next-Generation Integrated Optical Networks Based on Ultra-Wideband Radio / Técnicas Fotónicas para Redes Ópticas Integradas de Próxima Generación Basadas en Radio de Banda Ultra Ancha [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/15576 / Palancia
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Cooperative wireless channel characterization and modeling: application to body area and cellular networksLiu, Lingfeng 23 March 2012 (has links)
Cooperative wireless communication is an attractive technique to explore the spatial channel resources by coordination across multiple links, which can greatly improve the communication performance over single links. In this dissertation, we study the cooperative multi-link channel properties by geometric approaches in body area networks (BANs) and cellular networks respectively.<p><p>In the part of BANs, the dynamic narrowband on-body channels under body motions are modeled statistically on their temporal and spatial fading based on anechoic and indoor measurements. Common body scattering is observed to form inter-link correlation between links closely distributed and between links having synchronized movements of communication nodes. An analytical model is developed to explain the physical mechanisms of the dynamic body scattering. The on-body channel impacts to simple cooperation protocols are evaluated based on realistic measurements. <p><p>In the part of cellular networks, the cluster-level multi-link COST 2100 MIMO channel model is developed with concrete modeling concepts, complete parameterization and implementation methods, and a compatible structure for both single-link and multi-link scenarios. The cluster link-commonness is introduced to the model to describe the multi-link properties. The multi-link impacts by the model are also evaluated in a distributed MIMO system by comparing its sum-rate capacity at different ratios of cluster link-commonness. / Doctorat en Sciences de l'ingénieur / info:eu-repo/semantics/nonPublished
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Channel Probing for an Indoor Wireless Communications ChannelHunter, Brandon 13 March 2003 (has links) (PDF)
The statistics of the amplitude, time and angle of arrival of multipaths in an indoor environment are all necessary components of multipath models used to simulate the performance of spatial diversity in receive antenna configurations. The model presented by Saleh and Valenzuela, was added to by Spencer et. al., and included all three of these parameters for a 7 GHz channel. A system was built to measure these multipath parameters at 2.4 GHz for multiple locations in an indoor environment. Another system was built to measure the angle of transmission for a 6 GHz channel. The addition of this parameter allows spatial diversity at the transmitter along with the receiver to be simulated. The process of going from raw measurement data to discrete arrivals and then to clustered arrivals is analyzed. Many possible errors associated with discrete arrival processing are discussed along with possible solutions. Four clustering methods are compared and their relative strengths and weaknesses are pointed out. The effects that errors in the clustering process have on parameter estimation and model performance are also simulated.
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