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 20 of 21 for “"Noise shaping"”.
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A continuous-time multi-stage noise-shaping delta-sigma modulator with analog delay
A new continuous-time multi-stage noise-shaping delta-sigma modulator has been designed. This modulator provides high resolution and robust stability characteristics which are the primary advantages of the conventional multi-stage noise-shaping architecture. At the same time, previous critical …
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Noise shaping techniques for analog and time to digital converters using voltage controlled oscillators
… with first-order quantization and mismatch noise-shaping. To implement a time-to-digital converter (TDC) with noise-shaping, we present a oscillator that is enabled during the measurement of an input, and then disabled in between measurements. By holding the state of the oscillator in …
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A continuous-time multi-stage noise-shaping delta-sigma modulator for next generation wireless applications
… is investigated in this thesis. Quantization noise is suppressed aggressively by increasing the effective order of the noise transfer function (NTF). In order to increase the effective order of the NTF, a 2-loop sturdy multi-stage noise-shaping (SMASH) architecture is utilized. The proposed CT …
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Design of high fidelity pulse width modulation inverter
… The distortion effects are analyzed in depth. Noise-shaping processes that reduce quantization errors in the process are described. An inverter is presented that processes information directly in digital form PWM sequence with accurate correction added in the front end noise shaping module. The …
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Quantization and erasures in frame representations
… quantization, a generalization of Sigma-Delta noise shaping to arbitrary frame representations is developed by reformulating noise shaping as a sequence of compensations for the quantization error using projections.
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New strategies for low noise, agile PLL frequency synthesis
… fast switching and minimal spurious and phase noise. The conflict between high resolution and fast switching leads to two separate integer synthesisers to satisfy critical system requirements. This thesis concerns a new sigma-delta fractional-N synthesiser design which is able to be directly …
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A Distortion Suppression Technique for a Digital Class D Audio Power Amplifier with Pulse Density Modulation
… drive. Pulse Density Modulation (PDM) uses a noise shaping Delta Sigma Modulator (DSM), and generally requires a higher switching rate than PWM to obtain comparable THD performance. Techniques such as hysteresis can be used to reduce the rate to comparable levels. PDM also generates a more …
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Digital Pulse Width Modulation: Analysis, Algorithms, and Applications
… the implementation of real applications, the noise shaping technique is employed to reduce the resolution of quantization without compromising the signal to quantization noise ratio.
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An Exploratory Study of Pulse Width and Delta Sigma Modulators
<p>This paper explores the noise shaping and noise producing qualities of Delta-Sigma Modulators (DSM) and Pulse-Width Modulators (PWM). DSM has long been dominant in the Delta Sigma Analog-to-Digital Converter (DSADC) as a noise-shaped quantizer and time discretizer, while PWM, with a similar self …
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Digital pulse processing
… sigma-delta modulation used in oversampled noise-shaping converters. The encoder circuits are well known and have simple construction using both current and next-generation technologies. Processing in the pulse-domain provides many benefits including: lower area and power consumption, error …
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Pipelined oversampling analog-to-digital converters
Oversampling and noise-shaping techniques, such as [delta sigma] modulation, are widely used in analog-to-digital conversion to achieve accuracy that exceeds that of integrated-circuit components. Such converters have an inherent tradeoff between accuracy and speed, whereby resolution in amplitude …
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Analysis, simulation and design of nonlinear RF circuits
… need for expensive experiments. The Multi-stAge noise Shaping (MASH) digital delta-sigma modulator (DDSM) is simulated in MATLAB and analysed mathematically. A novel structure employing multimoduli, termed the MM-MASH, is proposed. The goal in this design work is to reduce the noise level in the …
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Continuous-Time Delta-Sigma Modulators for Ultra-Low-Power Radios
… analog part while still achieving a 2nd-order noise shaping. The thesis also examines the possibility of using a successive approximation register (SAR) quantizer instead of the commonly used flash quantizer to reduce the power consumption of the digital part as well.
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Theory and applications of delta-sigma analogue-to-digital converters without negative feedback
… components that are precise and highly immune to noise and interference. In contrast, oversampling converters can achieve high resolutions (>20bits) and can be implemented using straightforward, high-tolerance analog components. In conventional oversampled modulators, negative feedback is applied …
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Nonuniform subbard coding of high quality audio signals employing frequency warping
… on the new nonuniform filter bank is capable of noise shaping. A subband coder based on the nonuniform filter bank is constructed and results are presented. Objective assessment and informal subjective assessment are carried out and they show that the coding reaches high quality at 192 kbps per …
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Digital calibration of nonlinear memory errors in sigma-delta ADCs
… converters, an analog domain pseudorandom noise (PN) removal technique is devised to resolve the input signal dynamic range loss resulting from the PN circulation in modulator loops. Error model identification is accomplished by correlating various moments of the digital output with a …
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Techniques for high-performance digital frequency synthesis and phase control
… architecture that leverages a recently invented noise-shaping time-to-digital converter (TDC) and an all-digital quantization noise cancellation technique to achieve excellent in-band and out-of-band phase noise, respectively. In addition, a passive digital-to-analog converter (DAC) structure is …
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A subsampling delta-sigma modulator for global navigation satellite systems
… receivers has been limited due to their poor noise performance. This is particularly a concern in applications of Code Division Multiple Access (CDMA) such as GNSS since subsampling may saturate the Analog-to-Digital Converter (ADC) as the thermal noise floor is above the signals of interest. …
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Analysis and design of ΣΔ Modulators for Radio Frequency Switchmode Power Amplifiers
… by the digital hardware, which is needed for shaping large contents of a quantization noise induced by the modulator but also, the binary output from the modulator needs an RF power amplifier operating over very wide frequency band. This thesis addresses the problem of noise shaping in a ΣΔ …
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