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  • About
  • 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.
1

An RF System Design for an Ultra Wideband Indoor Positioning System

Parikh, Hemish K 11 March 2008 (has links)
Three main elements for an indoor positioning and navigation system design are the signal structure, the signal processing algorithm and the digital and RF prototype hardware. This thesis focuses on the design and development of RF prototype hardware. The signal structure being used in the precise positioning system discussed in this thesis is a Multicarrier-Ultra Wideband (MC-UWB) type signal structure. Unavailability of RF modules suitable for MC-UWB based systems, led to design and development of custom RF transmitter and receiver modules which can be used for extensive field testing. The lack of RF design guidelines for multicarrier positioning systems that operate over fractional bandwidth ranging from 10% to 25% makes the RF design challenging as the RF components are stressed using multicarrier signal in a way not anticipated by the designers. This thesis, first presents simulation based performance evaluation of impulse radio based and multicarrier based indoor positioning systems. This led to an important revelation that multicarrier based positioning system is preferred over impulse radio based positioning systems. Following this, ADS simulations for a direct upconversion transmitter and a direct downconversion receiver, using multicarrier signal structure is presented. The thesis will then discuss the design and performance of the 24% fractional bandwidth RF prototype transmitter and receiver custom modules. This optimized 24% fractional bandwidth RF design, under controlled testing environment demonstrates positioning accuracy improvement by 2-4 times over the initial 11% fractional bandwidth non-optimized RF design. The thesis will then present the results of various indoor wireless tests using the optimized RF prototype modules which led to better understanding of the issues in a field deployable indoor positioning system.
2

Projeto de um amplificador de baixo ruído em tecnologia CMOS 130nm para frequências de 50MHZ a 1GHz / A 50MHz-1GHz wideband low noise amplifier in 130nm CMOS technology

Pimentel, Henrique Luiz Andrade January 2012 (has links)
O presente trabalho tem por objetivo fornecer o embasamento teórico para o projeto de um amplificador de baixo ruído (LNA – Low Noise Amplifier) em tecnologia CMOS que opere em mais de uma faixa de frequência, de modo a permitir seu uso em receptores multibanda e de banda larga. A base teórica que este trabalho abrange desde a revisão bibliográfica do assunto em questão, passando pela análise dos modelos de transistores para alta-frequência, pelo estudo das especificações deste bloco e das métricas utilizadas em projetos de circuitos integrados de RF, bem como pela revisão de topologias clássicas existentes. Com os conhecimentos acima adquiridos, foi possível realizar o projeto de um LNA diferencial de banda larga utilizando tecnologia CMOS IBM 130nm, o qual pode ser aplicado ao padrão IEEE 802.22 para rádios cognitivos (CR). O projeto é baseado na técnica de cancelamento de ruído, sendo validado após apresentar efetiva redução de figura de ruído para banda de frequência desejada, com moderado consumo de potência e utilização moderada de área de silício, devido a solução sem o uso de indutores. O LNA banda larga opera em frequências de 50Mhz a 1GHz e apresenta uma figura de ruído abaixo de 4dB, em 90% da faixa, um ganho acima de 12dB, e perda de retorno na entrada e na saída maiores que 12dB. O IIP3 e a frequência de ocorrência de compressão a 1dB com a entrada em 580MHz estão acima de 0dBm e -10dBm respectivamente. Possui consumo de 46,5mWpara fonte de 1,5V e ocupa uma área ativa de apenas 0,28mm x 0,2mm. / This work presents the theoretical basis for the design of a low noise amplifier (LNA) in CMOS technology that operates in more than one frequency band, which enables its use in multi-band and wideband receivers. The theoretical basis that this work will address extends from the literature review on the subject, through the analysis of models of MOS transistors for high frequencies, study of specifications of this block and the metrics used in RF integrated circuit design, as well as the review of existing classical LNA topologies. Based on the knowledge acquired above, the design of a differential wideband LNA is developed using IBM 130nm RF CMOS process, which can be used in IEEE 802.22 Cognitive Radio (CR) applications. The design is based on the noise-canceling technique, with an indutctorless solution, showing that this technique effectively reduces the noise figure over the desired frequency range with moderate power consumption and a moderate utilization of silicon die area. The wideband LNA covers the frequency range from 50 MHz to 1 GHz, achieving a noise figure below 4dB in over 90% of the band of interest, a gain of 11dB to 12dB, and an input/output return loss higher than -12 dB. The input IIP3 and input P1dB at 580MHz are above 0dB and -10dB, respectively. It consumes 46.5mW from a 1.5V supply and occupies an active area of only 0.056mm2 (0.28mm x 0.2mm).
3

Projeto de um amplificador de baixo ruído em tecnologia CMOS 130nm para frequências de 50MHZ a 1GHz / A 50MHz-1GHz wideband low noise amplifier in 130nm CMOS technology

Pimentel, Henrique Luiz Andrade January 2012 (has links)
O presente trabalho tem por objetivo fornecer o embasamento teórico para o projeto de um amplificador de baixo ruído (LNA – Low Noise Amplifier) em tecnologia CMOS que opere em mais de uma faixa de frequência, de modo a permitir seu uso em receptores multibanda e de banda larga. A base teórica que este trabalho abrange desde a revisão bibliográfica do assunto em questão, passando pela análise dos modelos de transistores para alta-frequência, pelo estudo das especificações deste bloco e das métricas utilizadas em projetos de circuitos integrados de RF, bem como pela revisão de topologias clássicas existentes. Com os conhecimentos acima adquiridos, foi possível realizar o projeto de um LNA diferencial de banda larga utilizando tecnologia CMOS IBM 130nm, o qual pode ser aplicado ao padrão IEEE 802.22 para rádios cognitivos (CR). O projeto é baseado na técnica de cancelamento de ruído, sendo validado após apresentar efetiva redução de figura de ruído para banda de frequência desejada, com moderado consumo de potência e utilização moderada de área de silício, devido a solução sem o uso de indutores. O LNA banda larga opera em frequências de 50Mhz a 1GHz e apresenta uma figura de ruído abaixo de 4dB, em 90% da faixa, um ganho acima de 12dB, e perda de retorno na entrada e na saída maiores que 12dB. O IIP3 e a frequência de ocorrência de compressão a 1dB com a entrada em 580MHz estão acima de 0dBm e -10dBm respectivamente. Possui consumo de 46,5mWpara fonte de 1,5V e ocupa uma área ativa de apenas 0,28mm x 0,2mm. / This work presents the theoretical basis for the design of a low noise amplifier (LNA) in CMOS technology that operates in more than one frequency band, which enables its use in multi-band and wideband receivers. The theoretical basis that this work will address extends from the literature review on the subject, through the analysis of models of MOS transistors for high frequencies, study of specifications of this block and the metrics used in RF integrated circuit design, as well as the review of existing classical LNA topologies. Based on the knowledge acquired above, the design of a differential wideband LNA is developed using IBM 130nm RF CMOS process, which can be used in IEEE 802.22 Cognitive Radio (CR) applications. The design is based on the noise-canceling technique, with an indutctorless solution, showing that this technique effectively reduces the noise figure over the desired frequency range with moderate power consumption and a moderate utilization of silicon die area. The wideband LNA covers the frequency range from 50 MHz to 1 GHz, achieving a noise figure below 4dB in over 90% of the band of interest, a gain of 11dB to 12dB, and an input/output return loss higher than -12 dB. The input IIP3 and input P1dB at 580MHz are above 0dB and -10dB, respectively. It consumes 46.5mW from a 1.5V supply and occupies an active area of only 0.056mm2 (0.28mm x 0.2mm).
4

Projeto de um amplificador de baixo ruído em tecnologia CMOS 130nm para frequências de 50MHZ a 1GHz / A 50MHz-1GHz wideband low noise amplifier in 130nm CMOS technology

Pimentel, Henrique Luiz Andrade January 2012 (has links)
O presente trabalho tem por objetivo fornecer o embasamento teórico para o projeto de um amplificador de baixo ruído (LNA – Low Noise Amplifier) em tecnologia CMOS que opere em mais de uma faixa de frequência, de modo a permitir seu uso em receptores multibanda e de banda larga. A base teórica que este trabalho abrange desde a revisão bibliográfica do assunto em questão, passando pela análise dos modelos de transistores para alta-frequência, pelo estudo das especificações deste bloco e das métricas utilizadas em projetos de circuitos integrados de RF, bem como pela revisão de topologias clássicas existentes. Com os conhecimentos acima adquiridos, foi possível realizar o projeto de um LNA diferencial de banda larga utilizando tecnologia CMOS IBM 130nm, o qual pode ser aplicado ao padrão IEEE 802.22 para rádios cognitivos (CR). O projeto é baseado na técnica de cancelamento de ruído, sendo validado após apresentar efetiva redução de figura de ruído para banda de frequência desejada, com moderado consumo de potência e utilização moderada de área de silício, devido a solução sem o uso de indutores. O LNA banda larga opera em frequências de 50Mhz a 1GHz e apresenta uma figura de ruído abaixo de 4dB, em 90% da faixa, um ganho acima de 12dB, e perda de retorno na entrada e na saída maiores que 12dB. O IIP3 e a frequência de ocorrência de compressão a 1dB com a entrada em 580MHz estão acima de 0dBm e -10dBm respectivamente. Possui consumo de 46,5mWpara fonte de 1,5V e ocupa uma área ativa de apenas 0,28mm x 0,2mm. / This work presents the theoretical basis for the design of a low noise amplifier (LNA) in CMOS technology that operates in more than one frequency band, which enables its use in multi-band and wideband receivers. The theoretical basis that this work will address extends from the literature review on the subject, through the analysis of models of MOS transistors for high frequencies, study of specifications of this block and the metrics used in RF integrated circuit design, as well as the review of existing classical LNA topologies. Based on the knowledge acquired above, the design of a differential wideband LNA is developed using IBM 130nm RF CMOS process, which can be used in IEEE 802.22 Cognitive Radio (CR) applications. The design is based on the noise-canceling technique, with an indutctorless solution, showing that this technique effectively reduces the noise figure over the desired frequency range with moderate power consumption and a moderate utilization of silicon die area. The wideband LNA covers the frequency range from 50 MHz to 1 GHz, achieving a noise figure below 4dB in over 90% of the band of interest, a gain of 11dB to 12dB, and an input/output return loss higher than -12 dB. The input IIP3 and input P1dB at 580MHz are above 0dB and -10dB, respectively. It consumes 46.5mW from a 1.5V supply and occupies an active area of only 0.056mm2 (0.28mm x 0.2mm).
5

Development of Compact Phased Array Receivers on RFSoC Prototyping Platforms

Bartschi, Jacob 11 April 2022 (has links)
The continual increase of wireless technologies in the world has motivated the use of phased arrays to mitigate radio frequency interference (RFI). There are many methods of performing beamforming for RFI rejection, but they are traditionally physically large and complicated solutions. Phased arrays need to be shrunk and made cheaper for them to see widespread use. This work presents several compact phased array receivers for different applications. The first part of this thesis presents a software GPS processor for a digital beamforming GPS receiver. The receiver is small enough to be flown on drones and enables GPS signals to be processed and a user’s position to be determined. Using digital beamforming, it can operate even under poor conditions such as intentional jamming, RFI, and large multipath effects. Next, this work builds a frontend RF chain for a true time delay phased array receiver. The receiver uses analog true delay delay chips to mitigate radio frequency interference in sensitive instruments. True time delay allows for analog beamforming over a wide bandwidth, but compact true time delay solutions are new and untested. The receiver allows these solutions to be properly vetted in a full system. The chain uses novel compact wideband antennas for L-band frequencies and traditional low cost amplifiers and filters. The last section of this thesis updates the open-source CASPER project to fully support RF system-on-chips. CASPER is an open-source framework for radio astronomy instruments. It speeds up the design and implementation of radio astronomy instruments on compact platforms and makes them easier to interact with. This work expands the framework to use the transmit abilities of advanced RF system-on-chip platforms. With this expansion, full duplex systems such as communications and radar can now also use CASPER. A full loopback beamforming test built on CASPER demonstrates both transmit and receive beamforming.
6

Random Sequence Encoding with OFDM for Covert Communication and Signal Reuse for LPI/LPD Radar: Theory & Experiments

Kellett, Daniel 01 August 2017 (has links)
No description available.
7

Simulation multi-moteurs multi-niveaux pour la validation des spécifications système et optimisation de la consommation / Multi-engine multi-level simulation for system specification validation and power consumption optimization

Li, Fangyan 29 March 2016 (has links)
Ce travail vise la modélisation au niveau système, en langage SystemC-AMS, et la simulation d'un émetteur-récepteur au standard Bluetooth Low Energy (BLE). L'objectif est d'analyser la relation entre les performances, en termes de BER et la consommation d'énergie du transceiver. Le temps de simulation d’un tel système, à partir de cas d’étude (use case) réaliste, est un facteur clé pour le développement d’une telle plateforme. De plus, afin d’obtenir des résultats de simulation le plus précis possible, les modèles « haut niveau » doivent être raffinés à partir de modèles plus bas niveau où de mesure. L'approche dite Meet-in-the-Middle, associée à la méthode de modélisation équivalente en Bande Base (BBE, BaseBand Equivalent), a été choisie pour atteindre les deux conditions requises, à savoir temps de simulation « faible » et précision des résultats. Une simulation globale d'un système de BLE est obtenue en intégrant le modèle de l'émetteur-récepteur dans une plateforme existante développée en SystemC-TLM. La simulation est basée sur un système de communication de deux dispositifs BLE, en utilisant différents scénarios (différents cas d'utilisation de BLE). Dans un premier temps nous avons modélisé et validé chaque bloc d’un transceiver BT. Devant le temps de simulation prohibitif, les blocs RF sont réécrits en utilisant la méthodologie BB, puis raffinés afin de prendre en compte les non-linéarités qui vont impacter le couple consommation, BER. Chaque circuit (chaque modèle) est vérifié séparément, puis une première simulation système (point à point entre un émetteur et un récepteur) est effectuée / This work aims at system-level modelling a defined transceiver for Bluetooth Low energy (BLE) system using SystemC-AMS. The goal is to analyze the relationship between the transceiver performance and the accurate energy consumption. This requires the transceiver model contains system-level simulation speed and the low-level design block power consumption and other RF specifications. The Meet-in-the-Middle approach and the Baseband Equivalent method are chosen to achieve the two requirements above. A global simulation of a complete BLE system is achieved by integrating the transceiver model into a SystemC-TLM described BLE system model which contains the higher-than-PHY levels. The simulation is based on a two BLE devices communication system and is run with different BLE use cases. The transceiver Bit-Error-Rate and the energy estimation are obtained at the end of the simulation. First, we modelled and validated each block of a BT transceiver. In front of the prohibitive simulation time, the RF blocks are rewritten by using the BBE methodology, and then refined in order to take into account the non-linearities, which are going to impact the couple consumption, BER. Each circuit (each model) is separately verified, and then a first BLE system simulation (point-to-point between a transmitter and a receiver) has been executed. Finally, the BER is finally estimated. This platform fulfills our expectations, the simulation time is suitable and the results have been validated with the circuit measurement offered by Riviera Waves Company. Finally, two versions of the same transceiver architecture are modelled, simulated and compared

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