39 research outputs found

    Novel design strategies and architectures for continuous-time Sigma-Delta modulators

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    Multibit delta sigma modulator with noise shaping dynamic element matching

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    Ph.DDOCTOR OF PHILOSOPH

    Rapid Prototyping of Third-Order Sigma-Delta A/D Converters

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    Prototyping of third-order sigma-delta analog to digital converters (ƩΔADCs) has been presented in the paper. The method is based on implementation of field programmable analog arrays (FPAA) to configure and reconfigure proposed circuits. Three third-order ƩΔ ADC structures have been considered. The circuit characteristics have been measured and then the structure of the converters have been reconfigured to satisfy input specifications

    Contribution to the design of continuous -time Sigma - Delta Modulators based on time delay elements

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    The research carried out in this thesis is focused in the development of a new class of data converters for digital radio. There are two main architectures for communication receivers which perform a digital demodulation. One of them is based on analog demodulation to the base band and digitization of the I/Q components. Another option is to digitize the band pass signal at the output of the IF stage using a bandpass Sigma-Delta modulator. Bandpass Sigma- Delta modulators can be implemented with discrete-time circuits, using switched capacitors or continuous-time circuits. The main innovation introduced in this work is the use of passive transmission lines in the loop filter of a bandpass continuous-time Sigma-Delta modulator instead of the conventional solution with gm-C or LC resonators. As long as transmission lines are used as replacement of a LC resonator in RF technology, it seems compelling that transmission lines could improve bandpass continuous-time Sigma-Delta modulators. The analysis of a Sigma- Delta modulator using distributed resonators has led to a completely new family of Sigma- Delta modulators which possess properties inherited both from continuous-time and discretetime Sigma-Delta modulators. In this thesis we present the basic theory and the practical design trade-offs of this new family of Sigma-Delta modulators. Three demonstration chips have been implemented to validate the theoretical developments. The first two are a proof of concept of the application of transmission lines to build lowpass and bandpass modulators. The third chip summarizes all the contributions of the thesis. It consists of a transmission line Sigma-Delta modulator which combines subsampling techniques, a mismatch insensitive circuitry and a quadrature architecture to implement the IF to digital stage of a receiver

    Bandpass electromechanical sigma-delta modulator

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    Ph.DDOCTOR OF PHILOSOPH
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