Title :
Narrow-band variable center frequency single-loop and multistage sigma-delta modulators for bandpass signals
Author :
Al-Janabi, Mohammed ; Kale, Izzet ; Morling, Richard C S
Author_Institution :
Dept. of Electron. Syst., Westminster Univ., London, UK
fDate :
10/1/1999 12:00:00 AM
Abstract :
Oversampled narrow-band single-loop and multistage resonator-based bandpass sigma-delta (Σ-Δ) modulators that can accommodate different passband center to sampling frequency ratios are reported. These tunable bandpass configurations are designed by analytically determining and subsequently verifying through detailed empirical simulations the required compensation hardware to deliver enhanced noise-shaping. It is demonstrated that comparatively superior in-band signal-to-noise ratios and dynamic ranges are attributed to the inclusion of appropriate digital feedforward and feedback compensators within these structures
Keywords :
circuit feedback; compensation; feedforward; quantisation (signal); sigma-delta modulation; ADC; bandpass signals; compensation hardware; digital feedback compensators; digital feedforward compensators; dynamic range; empirical simulation; enhanced noise-shaping; in-band signal-to-noise ratios; multistage sigma-delta modulators; narrow-band variable center frequency; nonlinear feedback systems; oversampled sigma-delta modulators; quantization noise; single-loop sigma-delta modulators; tunable bandpass configurations; Analytical models; Delta-sigma modulation; Dynamic range; Frequency; Hardware; Narrowband; Noise shaping; Passband; Sampling methods; Signal to noise ratio;
Journal_Title :
Instrumentation and Measurement, IEEE Transactions on
