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Design & Implementation Of Low Power Sigma Delta ADCs For Wide Band ApplicationsHarish, C 01 1900 (has links) (PDF)
This thesis focuses on the design and implementation of low power Σ∆ ADCs in 130 nanometer CMOS technology. The design issues in the implementation of a third order ADC with a multi-bit and single bit quantizer are discussed.
The advancement in CMOS technology has led to designing as much of electronics systems as possible with the digital circuits and digital signal processing replacing analog processing in most cases. Hence there is a need for digitizing analog signals with analog to digital converter (ADC). In communication systems this needs to be done immediately after the antenna in a receiver system. As this is difficult to implement due to high speed and high power consumption, RF signal is converted to a lower intermediate frequency (IF) and digitized.
This work stresses low power implementation of high bandwidth Σ∆ ADCs for digitizing the IF. Design techniques involved in the implementation of a third order continuous time Σ∆ ADC with a 4 bit quantizer as well as a single bit quantizer for wide bandwidth are discussed. Moreover, a third order continuous time audio ADC implementation was also done. The behavioural modelling of the Σ∆ ADC along with clock jitter non-linearity model was developed and the issues in circuit design techniques are addressed. The continuous time ADCs’ major problem, namely, excess loop delay is discussed in detail and an efficient compensation technique for the same is implemented which allows a large reduction of power consumed by the ADC. Choice of loop filter architecture, quantizer and transistor level implementation are given that result in better immunity to offsets and process variations. Both the ADCs have been implemented using UMC 130 nm Mixed-mode RF-CMOS process and the simulation results for the multi-bit ADC gives a peak SNR of 56dB with a dynamic range of 65dB with power consumption of 2mW. The audio ADC achieves a peak SNR of 94.2dB with a dynamic range of 91dB.
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Jitter-Tolerance and Blocker-Tolerance of Delta-Sigma Analog-to-Digital Converters for Saw-Less Multi-Standard ReceiversAhmed, Ramy 1981- 14 March 2013 (has links)
The quest for multi-standard and software-defined radio (SDR) receivers calls for high flexibility in the receiver building-blocks so that to accommodate several wireless services using a single receiver chain in mobile handsets. A potential approach to achieve flexibility in the receiver is to move the analog-to-digital converter (ADC) closer to the antenna so that to exploit the enormous advances in digital signal processing, in terms of technology scaling, speed, and programmability. In this context, continuous-time (CT) delta-sigma (ΔƩ) ADCs show up as an attractive option. CT ΔƩ ADCs have gained significant attention in wideband receivers, owing to their amenability to operate at a higher-speed with lower power consumption compared to discrete-time (DT) implementations, inherent anti-aliasing, and robustness to sampling errors in the loop quantizer. However, as the ADC moves closer to the antenna, several blockers and interferers are present at the ADC input. Thus, it is important to investigate the sensitivities of CT ΔƩ ADCs to out-of-band (OOB) blockers and find the design considerations and solutions needed to maintain the performance of CT ΔƩ modulators in presence of OOB blockers. Also, CT ΔƩ modulators suffer from a critical limitation due to their high sensitivity to the clock-jitter in the feedback digital-to-analog converter (DAC) sampling-clock.
In this context, the research work presented in this thesis is divided into two main parts. First, the effects of OOB blockers on the performance of CT ΔƩ modulators are investigated and analyzed through a detailed study. A potential solution is proposed to alleviate the effect of noise folding caused by intermodulation between OOB blockers and shaped quantization noise at the modulator input stage through current-mode integration. Second, a novel DAC solution that achieves tolerance to pulse-width jitter by spectrally shaping the jitter induced errors is presented. This jitter-tolerant DAC doesn’t add extra requirements on the slew-rate or the gain-bandwidth product of the loop filter amplifiers. The proposed DAC was implemented in a 90nm CMOS prototype chip and provided a measured attenuation for in-band jitter induced noise by 26.7dB and in-band DAC noise by 5dB, compared to conventional current-steering DAC, and consumes 719µwatts from 1.3V supply.
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Electromagnetic Band Gap (EBG) synthesis and its application in analog-to-digital converter load boardsKim, Tae Hong 06 December 2007 (has links)
With increase in frequency and convergence toward mixed signal systems, supplying stable voltages to integrated circuits and blocking noise coupling in the systems are major problems. Electromagnetic band gap (EBG) structures have been in the limelight for power/ground noise isolation in mixed signal applications due to their capability to suppress unwanted electromagnetic mode transmission in certain frequency bands. The EBG structures have proven effective in isolating the power/ground noise in systems that use a common power supply. However, while the EBG structures have the potential to present many advantages in noise suppression applications, there is no method in the prior art that enables reliable and efficient synthesis of these EBG structures.
Therefore, in this research, a novel EBG synthesis method for mixed signal applications is presented. For one-dimensional periodic structures, three new approaches such as current path approximation method, border to border radius, power loss method have been introduced and combined for synthesis. For two-dimensional EBG structures, a novel EBG synthesis method using genetic algorithm (GA) has been presented. In this method, genetic algorithm (GA) is utilized as a solution-searching technique. Synthesis procedure has been automated by combining GA with multilayer finite-difference method and dispersion diagram analysis method. As a real application for EBG structures, EBG structures have been applied to a GHz ADC load board design for power/ground noise suppression.
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Projeto e análise de moduladores sigma-delta em tempo contínuo aplicados à conversão ADAguirre, Paulo Cesar Comassetto de January 2014 (has links)
Conversores analógico-digitais (ADCs) têm papel fundamental na implementação dos sistemas-em-chip, do inglês System-on-Chip (SoC), atuais. Em razão dos requisitos destes sistemas e dos compromissos entre as características fundamentais dos ADCs, como largura de banda, consumo de energia e exatidão, diversas topologias e estratégias para sua implementação em circuitos integrados (CIs) têm sido desenvolvidas através dos tempos. Dentre estas topologias, os conversores sigma-delta (SDC) têm se destacado pela versatilidade, aliada ao baixo consumo e excelente exatidão. Inicialmente desenvolvidos e empregados para a conversão de sinais de baixa frequência e com operação em tempo discreto (DT), esta classe de conversores têm evoluído e nos últimos anos está sendo desenvolvida para operar em tempo contínuo e ser empregada na conversão de sinais com frequências de centenas de kHz a dezenas de MHz. Neste trabalho, os moduladores sigma-delta em tempo contínuo (SDMs-CT) são estudados, visando sua aplicação à conversão analógico-digital (AD). Os SDMs-CT oferecem vantagens significativas sobre seus homólogos em tempo discreto, como menor consumo de energia, maior largura de banda do sinal de entrada e filtro anti-alias, do inglês anti-alias filter (AAF), implícito. Entretanto, os SDMs-CT apresentam limitações adicionais, responsáveis pela degradação de seu desempenho, como os efeitos do jitter do sinal de relógio, o atraso excessivo do laço de realimentação, do inglês Excess Loop Delay (ELD), e as limitações impostas aos integradores analógicos. Após o estudo e análise de SDMs-CT e de suas limitações, foi desenvolvido um modelo comportamental no ambiente Matlab/Simulink R , que permite a simulação do impacto destas limitações no modulador, possibilitando a obtenção de uma estimativa mais aproximada do seu desempenho. Com base nestas simulações foi possível a determinação das especificações mínimas de cada bloco analógico que compõe o modulador (como o slew rate, a frequência de ganho unitário (fu) e o ganho DC dos amplificadores operacionais utilizados nos integradores) e os valores toleráveis de ELD e jitter do sinal de relógio. Adicionalmente, neste trabalho foi desenvolvida uma metodologia para simulação de SDMs-CT compostos por DACs a capacitor chaveado e resistor, do inglês Switched-Capacitor-Resistor (SCR). Com base neste modelo e no estudo das diferentes topologias de SDMs, um circuito foi desenvolvido para aplicação em receptores de RF, sendo do tipo passa-baixas de laço único, do inglês single-loop, single-bit, de terceira ordem, voltado ao baixo consumo de energia. Este circuito foi desenvolvido em tecnologia CMOS IBM de 130 nanômetros, tendo sido enviado para fabricação. Através das simulações pós-leiaute realizadas espera-se que seu desempenho fique próximo ao que tem sido publicado recentemente sobre SDMs-CT passa-baixas de laço único e single-bit. / Analog-to-Digital Converters (ADCs) play a fundamental role in the implementation of current systems-on-chip (SoC). Due to the requirements of these systems and the tradeoffs between the main ADCs characteristics, such as signal bandwidth, power consumption and accuracy, many topologies and strategies for their implementation in integrated circuits (ICs) have been developed through the ages. Among these topologies, the sigmadelta converters (SDC) have highlighted the versatility combined with low power consumption and excellent accuracy. Initially developed and used for the conversion of low frequency signals and operation in the discrete time (DT) domain, this class of converters have been evolved and developed over the past to operate in continuous time domain for the conversion of signals with frequencies of hundreds of kHz up to tens of MHz. In this work, continuous time sigma-delta modulators (CT-SDMs) are studied focusing its application to the analog-to-digital (AD) conversion. CT-SDMs offer significant advantages over their discrete-time counterparts, such as lower power consumption, higher input signal bandwidth and implicit anti-alias filter (AAF). However, CT-SDMs present additional limitations that are responsible for their performance degradation, such as the clock jitter, Excess Loop Delay (ELD) and the limitations imposed on the analog integrators. After the study and analysis of CT-SDMs and their performance limitations, a behavioral model approach was developed in the Matlab/Simulink R environment, which allows the simulation of the limitations impact on the modulator, allowing the obteinment of a more accurate estimate of its performance. Based on these simulations it was possible to determine the minimum specifications for each block that composes the analog modulator (such as slew rate, the unity gain frequency (fu) and the DC gain of the operational amplifiers used in integrators) and tolerable values of ELD and clock jitter. Additionally, it was developed in this work a methodology for simulate CT-SDMs with Switched-Capacitor- Resistor (SCR) DACs that provide exponential waveforms. Based on this model and the study of different SDMs topologies, it was developed a low-pass, single-loop, single-bit, third order circuit focused on low-power intended for application in RF receivers. This circuit was developed in an IBM 130 nanometers CMOS technology, and was send to manufacturing. Based on the post-layout simulations it is expected to have performance close to what has been recently published of low-pass, single-loop, single-bit CT-SDMs.
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Projeto e análise de moduladores sigma-delta em tempo contínuo aplicados à conversão ADAguirre, Paulo Cesar Comassetto de January 2014 (has links)
Conversores analógico-digitais (ADCs) têm papel fundamental na implementação dos sistemas-em-chip, do inglês System-on-Chip (SoC), atuais. Em razão dos requisitos destes sistemas e dos compromissos entre as características fundamentais dos ADCs, como largura de banda, consumo de energia e exatidão, diversas topologias e estratégias para sua implementação em circuitos integrados (CIs) têm sido desenvolvidas através dos tempos. Dentre estas topologias, os conversores sigma-delta (SDC) têm se destacado pela versatilidade, aliada ao baixo consumo e excelente exatidão. Inicialmente desenvolvidos e empregados para a conversão de sinais de baixa frequência e com operação em tempo discreto (DT), esta classe de conversores têm evoluído e nos últimos anos está sendo desenvolvida para operar em tempo contínuo e ser empregada na conversão de sinais com frequências de centenas de kHz a dezenas de MHz. Neste trabalho, os moduladores sigma-delta em tempo contínuo (SDMs-CT) são estudados, visando sua aplicação à conversão analógico-digital (AD). Os SDMs-CT oferecem vantagens significativas sobre seus homólogos em tempo discreto, como menor consumo de energia, maior largura de banda do sinal de entrada e filtro anti-alias, do inglês anti-alias filter (AAF), implícito. Entretanto, os SDMs-CT apresentam limitações adicionais, responsáveis pela degradação de seu desempenho, como os efeitos do jitter do sinal de relógio, o atraso excessivo do laço de realimentação, do inglês Excess Loop Delay (ELD), e as limitações impostas aos integradores analógicos. Após o estudo e análise de SDMs-CT e de suas limitações, foi desenvolvido um modelo comportamental no ambiente Matlab/Simulink R , que permite a simulação do impacto destas limitações no modulador, possibilitando a obtenção de uma estimativa mais aproximada do seu desempenho. Com base nestas simulações foi possível a determinação das especificações mínimas de cada bloco analógico que compõe o modulador (como o slew rate, a frequência de ganho unitário (fu) e o ganho DC dos amplificadores operacionais utilizados nos integradores) e os valores toleráveis de ELD e jitter do sinal de relógio. Adicionalmente, neste trabalho foi desenvolvida uma metodologia para simulação de SDMs-CT compostos por DACs a capacitor chaveado e resistor, do inglês Switched-Capacitor-Resistor (SCR). Com base neste modelo e no estudo das diferentes topologias de SDMs, um circuito foi desenvolvido para aplicação em receptores de RF, sendo do tipo passa-baixas de laço único, do inglês single-loop, single-bit, de terceira ordem, voltado ao baixo consumo de energia. Este circuito foi desenvolvido em tecnologia CMOS IBM de 130 nanômetros, tendo sido enviado para fabricação. Através das simulações pós-leiaute realizadas espera-se que seu desempenho fique próximo ao que tem sido publicado recentemente sobre SDMs-CT passa-baixas de laço único e single-bit. / Analog-to-Digital Converters (ADCs) play a fundamental role in the implementation of current systems-on-chip (SoC). Due to the requirements of these systems and the tradeoffs between the main ADCs characteristics, such as signal bandwidth, power consumption and accuracy, many topologies and strategies for their implementation in integrated circuits (ICs) have been developed through the ages. Among these topologies, the sigmadelta converters (SDC) have highlighted the versatility combined with low power consumption and excellent accuracy. Initially developed and used for the conversion of low frequency signals and operation in the discrete time (DT) domain, this class of converters have been evolved and developed over the past to operate in continuous time domain for the conversion of signals with frequencies of hundreds of kHz up to tens of MHz. In this work, continuous time sigma-delta modulators (CT-SDMs) are studied focusing its application to the analog-to-digital (AD) conversion. CT-SDMs offer significant advantages over their discrete-time counterparts, such as lower power consumption, higher input signal bandwidth and implicit anti-alias filter (AAF). However, CT-SDMs present additional limitations that are responsible for their performance degradation, such as the clock jitter, Excess Loop Delay (ELD) and the limitations imposed on the analog integrators. After the study and analysis of CT-SDMs and their performance limitations, a behavioral model approach was developed in the Matlab/Simulink R environment, which allows the simulation of the limitations impact on the modulator, allowing the obteinment of a more accurate estimate of its performance. Based on these simulations it was possible to determine the minimum specifications for each block that composes the analog modulator (such as slew rate, the unity gain frequency (fu) and the DC gain of the operational amplifiers used in integrators) and tolerable values of ELD and clock jitter. Additionally, it was developed in this work a methodology for simulate CT-SDMs with Switched-Capacitor- Resistor (SCR) DACs that provide exponential waveforms. Based on this model and the study of different SDMs topologies, it was developed a low-pass, single-loop, single-bit, third order circuit focused on low-power intended for application in RF receivers. This circuit was developed in an IBM 130 nanometers CMOS technology, and was send to manufacturing. Based on the post-layout simulations it is expected to have performance close to what has been recently published of low-pass, single-loop, single-bit CT-SDMs.
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Projeto e análise de moduladores sigma-delta em tempo contínuo aplicados à conversão ADAguirre, Paulo Cesar Comassetto de January 2014 (has links)
Conversores analógico-digitais (ADCs) têm papel fundamental na implementação dos sistemas-em-chip, do inglês System-on-Chip (SoC), atuais. Em razão dos requisitos destes sistemas e dos compromissos entre as características fundamentais dos ADCs, como largura de banda, consumo de energia e exatidão, diversas topologias e estratégias para sua implementação em circuitos integrados (CIs) têm sido desenvolvidas através dos tempos. Dentre estas topologias, os conversores sigma-delta (SDC) têm se destacado pela versatilidade, aliada ao baixo consumo e excelente exatidão. Inicialmente desenvolvidos e empregados para a conversão de sinais de baixa frequência e com operação em tempo discreto (DT), esta classe de conversores têm evoluído e nos últimos anos está sendo desenvolvida para operar em tempo contínuo e ser empregada na conversão de sinais com frequências de centenas de kHz a dezenas de MHz. Neste trabalho, os moduladores sigma-delta em tempo contínuo (SDMs-CT) são estudados, visando sua aplicação à conversão analógico-digital (AD). Os SDMs-CT oferecem vantagens significativas sobre seus homólogos em tempo discreto, como menor consumo de energia, maior largura de banda do sinal de entrada e filtro anti-alias, do inglês anti-alias filter (AAF), implícito. Entretanto, os SDMs-CT apresentam limitações adicionais, responsáveis pela degradação de seu desempenho, como os efeitos do jitter do sinal de relógio, o atraso excessivo do laço de realimentação, do inglês Excess Loop Delay (ELD), e as limitações impostas aos integradores analógicos. Após o estudo e análise de SDMs-CT e de suas limitações, foi desenvolvido um modelo comportamental no ambiente Matlab/Simulink R , que permite a simulação do impacto destas limitações no modulador, possibilitando a obtenção de uma estimativa mais aproximada do seu desempenho. Com base nestas simulações foi possível a determinação das especificações mínimas de cada bloco analógico que compõe o modulador (como o slew rate, a frequência de ganho unitário (fu) e o ganho DC dos amplificadores operacionais utilizados nos integradores) e os valores toleráveis de ELD e jitter do sinal de relógio. Adicionalmente, neste trabalho foi desenvolvida uma metodologia para simulação de SDMs-CT compostos por DACs a capacitor chaveado e resistor, do inglês Switched-Capacitor-Resistor (SCR). Com base neste modelo e no estudo das diferentes topologias de SDMs, um circuito foi desenvolvido para aplicação em receptores de RF, sendo do tipo passa-baixas de laço único, do inglês single-loop, single-bit, de terceira ordem, voltado ao baixo consumo de energia. Este circuito foi desenvolvido em tecnologia CMOS IBM de 130 nanômetros, tendo sido enviado para fabricação. Através das simulações pós-leiaute realizadas espera-se que seu desempenho fique próximo ao que tem sido publicado recentemente sobre SDMs-CT passa-baixas de laço único e single-bit. / Analog-to-Digital Converters (ADCs) play a fundamental role in the implementation of current systems-on-chip (SoC). Due to the requirements of these systems and the tradeoffs between the main ADCs characteristics, such as signal bandwidth, power consumption and accuracy, many topologies and strategies for their implementation in integrated circuits (ICs) have been developed through the ages. Among these topologies, the sigmadelta converters (SDC) have highlighted the versatility combined with low power consumption and excellent accuracy. Initially developed and used for the conversion of low frequency signals and operation in the discrete time (DT) domain, this class of converters have been evolved and developed over the past to operate in continuous time domain for the conversion of signals with frequencies of hundreds of kHz up to tens of MHz. In this work, continuous time sigma-delta modulators (CT-SDMs) are studied focusing its application to the analog-to-digital (AD) conversion. CT-SDMs offer significant advantages over their discrete-time counterparts, such as lower power consumption, higher input signal bandwidth and implicit anti-alias filter (AAF). However, CT-SDMs present additional limitations that are responsible for their performance degradation, such as the clock jitter, Excess Loop Delay (ELD) and the limitations imposed on the analog integrators. After the study and analysis of CT-SDMs and their performance limitations, a behavioral model approach was developed in the Matlab/Simulink R environment, which allows the simulation of the limitations impact on the modulator, allowing the obteinment of a more accurate estimate of its performance. Based on these simulations it was possible to determine the minimum specifications for each block that composes the analog modulator (such as slew rate, the unity gain frequency (fu) and the DC gain of the operational amplifiers used in integrators) and tolerable values of ELD and clock jitter. Additionally, it was developed in this work a methodology for simulate CT-SDMs with Switched-Capacitor- Resistor (SCR) DACs that provide exponential waveforms. Based on this model and the study of different SDMs topologies, it was developed a low-pass, single-loop, single-bit, third order circuit focused on low-power intended for application in RF receivers. This circuit was developed in an IBM 130 nanometers CMOS technology, and was send to manufacturing. Based on the post-layout simulations it is expected to have performance close to what has been recently published of low-pass, single-loop, single-bit CT-SDMs.
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Convertisseur analogique-numérique large bande avec correction mixte / Mixed calibration for high speed analog-to-digital convertersMas, Alexandre 10 July 2018 (has links)
Les besoins en débit d’information à transmettre ne cessent de croitre. Aussi la généralisation des émetteurs-récepteurs large-bande implique l’intégration de solutions sur une technologie silicium CMOS afin que leur cout soit compatible avec une application grand public. Si l’intégration massive des traitements numériques est facilitée par les dernières technologies CMOS, la fonction de conversion analogique-numérique est quant à elle plus difficile. En effet, afin d’optimiser l’étage frontal analogique, le convertisseur analogique-numérique (CAN) doit répondre à des contraintes très fortes en termes de largeur de bande (de l’ordre du GHz) et de résolution (de 10 à 14bits). Les convertisseurs analogique-numérique basés sur l’entrelacement temporel (CAN-ET) connaissent un essor remarquable car ce sont aujourd’hui les seuls à pouvoir répondre aux deux contraintes énoncées ci-dessus. Cependant, cette structure de CAN reste sensible aux défauts d’appariement entre ses différentes voies de conversion et voit ses performances limitées par la présence de raies parasites liées à des erreurs statiques (offset et gain) et dynamiques (skew et bande passante). Pour réduire l’impact des erreurs dynamiques, nous avons implémenté une calibration mixte en technologie FD-SOI 28nm. Dans une première partie, un état de l’art portant sur les différentes techniques de minimisation et de compensations analogiques des erreurs de skew et bande passante est réalisé. A partir de cette étude, nous proposons différentes techniques analogiques pour compenser les d´esappariements de bande passante et de skew. Pour compenser le skew, nous profitons des avantages de la technologie FD-SOI en modulant fortement la tension de la face arrière d’un ou plusieurs transistor(s) d’ échantillonnage. Concernant l’erreur de bande passante, nous proposons d’ajuster la résistance équivalente du T/H en adaptant la résistance à l’état passant des transistors d’échantillonnage de cinq manières différentes. Pour définir parmi toutes les compensations proposées celle qui est la plus adaptée à nos besoins, nous comparons différents critères de performance. Après avoir identifié la meilleure compensation de skew et de bande passante, nous avons, dans une dernière partie, implémenté une calibration mixte des erreurs statiques et dynamiques o`u l’estimation numérique est basée sur la méthode des Moindres Carrés. / Data transmission requirements are ever more stringent, with respect to more throughput, less power consumption and reduced cost. The cable TV market is where broadband transceivers must continuously innovate to meet these requirements. In these transceivers, the analog front-end part must be adapted to meet the increasingly tighter specifications of the newest standards. A key bottleneck is the Analogto- Digital Converter (ADC), which must reach a sampling rate of several Gigasamples per second at effective conversion resolutions in the range of 10 to 14 bits. Among the possible choices, converters based on Time-Interleaving (TI-ADC) are experiencing remarkable growth, and today they appear to be the best candidates to rmeet the two constraints set out above. However, TI-ADCs are hampered by mismatches between its different conversion channels, which result in degraded performance due to the appearance of mismatch spurs in the frequency domain, arising both from static errors (gain and offset mismatch) and dynamic (skew and bandwidth) errors. To reduce these errors, we have investigated a mixeddomain calibration strategy for TI-ADCS in 28nm FDSOI technology. We strongly focused the analog compensation of dynamic errors. This report begins with a review of the state-of-theart w.r.t. the mismatch reduction and analog compensation techniques for both dynamic errors. Based on these results, we then introduce a variety of analog techniques aimed at compensating the bandwidth and skew mismatches. In order to compensate for the skew, we make the most of the FD-SOI technology by tightly regulating the voltage of the back gate of one or several sampling transistors. For the bandwidth error, we recommend that the T/H equivalent resistor be adjusted, adapting the on-resistor of the sampling transistors using up to five different techniques. Once the most appropriate skew and bandwidth compensations were identified, we ultimately implemented a mixed calibration of static and dynamic errors along with a digital calculation based upon the "Least- Squares" method.
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A Software Defined Ultra Wideband Transceiver Testbed for Communications, Ranging, or ImagingAnderson, Christopher R. 14 November 2006 (has links)
Impulse Ultra Wideband (UWB) communications is an emerging technology that promises a number of benefits over traditional narrowband or broadband signals: extremely high data rates, extremely robust operation in dense multipath environments, low probability of intercept/detection, and the ability to operate concurrently with existing users. Unfortunately, most currently available UWB systems are based on dedicated hardware, preventing researchers from investigating algorithms or architectures that take advantage of some of the unique properties of UWB signals.
This dissertation outlines the development of a general purpose software radio transceiver testbed for UWB signals. The testbed is an enabling technology that provides a development platform for investigating ultra wideband communication algorithms (e.g., acquisition, synchronization, modulation, multiple access), ranging or radar (e.g., precision position location, intrusion detection, heart and respiration rate monitoring), and could potentially be used in the area of ultra wideband based medical imaging or vital signs monitoring. As research into impulse ultra wideband expands, the need is greater now than ever for a platform that will allow researchers to collect real-world performance data to corroborate theoretical and simulation results.
Additionally, this dissertation outlines the development of the Time-Interleaved Analog to Digital Converter array which served as the core of the testbed, along with a comprehensive theoretical and simulation-based analysis on the effects of Analog to Digital Converter mismatches in a Time-Interleaved Sampling array when the input signal is an ultra wideband Gaussian Monocycle. Included in the discussion is a thorough overview of the implementation of both a scaled-down prototype as well as the final version of the testbed. This dissertation concludes by evaluating the of the transceiver testbed in terms of the narrowband dynamic range, the accuracy with which it can sample and reconstruct a UWB pulse, and the bit error rate performance of the overall system. / Ph. D.
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A CMOS analog pulse compressor with a low-power analog-to-digital converter for MIMO radar applicationsLee, Sang Min 10 November 2010 (has links)
Multiple-input multiple-output (MIMO) radars, which utilize multiple transmitters and receivers to send and receive independent waveforms, have been actively investigated as a next generation radar technology inspired by MIMO techniques in communication theory. Complementary metal-oxide-semiconductor (CMOS) technology offers an opportunity for dramatic cost and size reduction for a MIMO array. However, the resulting formidable signal processing burden has not been addressed properly and remains a challenge. On the other hand, from a block-level point of view, an analog-to-digital converter (ADC) is required for mixed-signal processing to convert analog signals to digital signals, but an ADC occupies a significant portion of a system's budget. Therefore, improvement of an ADC will greatly enhance various trade-offs. This research presents an alternative and viable approach for a MIMO array from a system architecture point of view, and also develops circuit level improvement techniques for an ADC.
This dissertation presents a fully-integrated analog pulse compressor (APC) based on an analog matched filter in a mixed signal domain as a key block for the waveform diversity MIMO radar. The performance gain of the proposed system is mathematically presented, and the proposed system is successfully implemented and demonstrated from the block level to the system level using various waveforms. Various figures of merit are proposed to aid system evaluations. This dissertation also presents a low-power ADC based on an asynchronous sample-and-hold multiplying SAR (ASHMSAR) with an enhanced input range dynamic comparator as a key element of a future system. Overall, with the new ADC, a high level of system performance without severe penalty on power consumption is expected.
The research in this dissertation provides low-cost and low-power MIMO solutions for a future system by addressing both system issues and circuit issues comprehensively.
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"Analogue Network of Converters": a DfT Technique to Test a Complete Set of ADCs and DACs Embedded in a Complex SiP or SoCKerzerho, Vincent 22 February 2008 (has links) (PDF)
Une nouvelle méthode de test pour les convertisseurs ADC et DAC embarqués dans un système complexe a été développée en prenant en compte les nouvelles contraintes affectant le test. Ces contraintes, dues aux tendances de design de systèmes, sont un nombre réduit de point d'accès aux entrées/sorties des blocs analogiques du système et une augmentation galopante du nombre et des performances des convertisseurs intégrés. La méthode proposée consiste à connecter les convertisseurs DAC et ADC dans le domaine analogique pour n'avoir besoin que d'instruments de test numériques pour générer et capturer les signaux de test. Un algorithme de traitement du signal a été développé pour discriminer les erreurs des DACs et ADCs. Cet algorithme a été validé par simulation et par expérimentation sur des produits commercialisés par NXP. La dernière partie de la thèse a consisté à développer de nouvelles applications pour l'algorithme.
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