Global ETD Search
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Showing 1 to 15 of 15 for “"Sigma-delta modulator"”.
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A bandpass sigma delta modulator IF receiver
Thesis (M. Eng.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 1997.
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An improved sigma-delta modulator for digitizing carrier band measurements
Draper Laboratory currently employs a third-order Sigma-Delta modulator to digitize the outputs from microelectromechanical sensors at the intermediate frequency prior to demodulation inside a field programmable gate array. This modulator, which is built on a .5[mu]m CMOS process, is to be used as …
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A continuous time sigma-delta modulator for digitizing carrier band measurements
Thesis (M.Eng.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2001.
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Low-power switched-capacitor amplifier and Sigma-Delta modulator design for integrated biosensor applications
… of a low power switched-capacitor amplifier and Sigma-Delta modulator for use as an analog-to-digital converter. The switched-capacitor amplifier achieves a gain of 40dB with -63.7dB total harmonic distortion while using 6.82μW and occupying 0.076mm2 silicon area. The Sigma-Delta modulator …
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A fourth order [Sigma] [Delta] bandpass modulator
A fourth order bandpass [Sigma] [Delta] modulator is proposed to digitize signals from a MEMS gyroscope. The modulator samples the amplitude-modulated signal at eight times the carrier frequency and achieves an SNR of 82dB with a sampling frequency of 640kHz and a bandwidtn o 1.oKnz. ms document …
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Design and implementation of generalized topologies of time-interleaved variable bandpass Σ−Δ modulators
… generalized time-interleaved variable bandpass sigma-delta modulators are designed, analysed, evaluated and implemented that are suitable for high performance data conversion for a broad-spectrum of applications. These generalized time-interleaved variable bandpass sigma-delta modulators can …
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Support-vector-machine based automatic performance modelling and optimisation for analogue and mixed-signal designs
… example is a high-level model of a mixed-signal sigma-delta modulator which comprises most of the practical design nonlinearities and imperfections that are known to affect the performance. The proposed method is able to find designs with significantly superior key performance figures compared to …
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Development of a micromachined electrostatically suspended gyroscope
… electrostatic suspension system based on a sigma delta modulator (ΣΔM). The system, in turn, produces feedback forces to counteract themovement of the mass, moving it back to its nominal position. These feedback forces are equal to the precession torque and provide a measure of the rotation …
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Circuitos digitais e mistos CMOS com aplicação em medidor de energia
… consumption reduced by 26%. A pseudo-parallel sigma-delta modulator that was optimized at system level to attain maximum SNR using minimum capacitance values so that speed requirements of the analog blocks could be alleviated in order to reduce power consumption. The developed PSDM was verified …
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Mixed-signal analog-digital circuits design on the pre-diffused digital array using trapezoidal association of transistors
… system, i. e., a fully differential 2nd order Sigma-Delta Analog-to-Digital (A/D) modulator, fabricated in both full-custom and SOT array methodologies in 0.5mm CMOS technology from MOSIS foundry. Three test-chips were designed and fabricated in 0.5mm. Two of them are IC chips containing the …
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CMOS Readout Interfaces for MEMS Capacitive Microphones
… a bootstrapped preamplifier and a third-order sigma-delta modulator (SDM) for analog-to-digital conversion. The preamplifier is bootstrapped to the MCM by tying its output to the sensorâ€TMs substrate. This bootstrapping technique boosts the MCM signal by ~17dB and also makes the readout …
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Power-efficient and high-performance interference resilientpulse oximeter
This thesis presents a novel sigma delta-based pulse oximeter with higher resilience against ambient light interference in comparison to the conventional pulse oximeters available in the market. The pulse oximeter reported in this thesis uses a novel cross-coupled sigma delta modulator to drive the …
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Time-based circuits for communication systems in advanced CMOS technology
… this work, we present A/D converters and an RF modulator based on ring oscillators in deep sub-micron CMOS processes. We introduce a VCO-based [sigma][delta] A/D converter utilizing a voltage-controlled ring oscillator (ring VCO) as a continuous-time integrator. We propose to replace …
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Integration of energy storage components with cascaded H-bridge multilevel converters
… cells run at the PWM frequency. Finally, the sigma-delta modulation method has been utilized to extend the capacitor voltage regulation range. This method benefits from simplicity in implementation in comparison to PWM techniques. The analytical and simulation results prove the effectiveness …
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A contribution to continuous-time quadrature bandpass sigma-delta modulators for low-IF receivers
… of the continuous-time quadrature bandpass sigma-delta modulators (CT-QBP SDMs). CT-QBP SDMs is well suited for low-IF receivers due to some significant advantages over other implementations. Firstly, the possible design methodologies have been defined and compared. The proposed inverse …