Direct All-Digital Frequency Synthesis Techniques, Spurs Suppression, and Deterministic Jitter Correction

2015 Joint Conference of the IEEE International Frequency Control Symposium &Amp; The European Frequency and Time Forum

2015

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A configurable single-bit-output Σ-Δ modulator variant is presented, which improves upon stability and dynamic range. The derivation of the proposed modulation scheme from the Σ-Δ error-feedback structure and its mathematical description are analyzed, while its application in fractional-N frequency dividers and all-digital frequency synthesizers is investigated. It is shown that stable high-order noise shaping is possible even when using noise transfer functions that are unstable in a conventional Σ-Δ modulator loop. Furthermore, multipliers can be avoided if the noise transfer function coefficients are chosen appropriately, leading to a low complexity hardware implementation. In special cases the architecture is equivalent to another Σ-Δ modulator with a different, stable, NTF than the initial one. The effectiveness of the proposed modulation scheme is demonstrated by specific examples for each application.978-1-4799-8866-2/15/$31.00 ©2015 IEEE

Section: Introductionmentioning

confidence: 99%

Single-bit-output all-digital frequency synthesis using multi-step look-ahead bandpass Σ-Δ modulator-like quantization processing

Basetas

2015 Joint Conference of the IEEE International Frequency Control Symposium &Amp; The European Frequency and Time Forum

2015

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“…Efforts have been made to remove the DAC, the only mixed-signal block, in DDS leading to Pulse-DDS (PDDS) [5], [9], [10]. This however introduces the challenging task of generating single-bit digital signals of desirable sinewavelike spectrum using only the reference clock [6], [9] [2].…”

Section: Introductionmentioning

confidence: 99%

“…This however introduces the challenging task of generating single-bit digital signals of desirable sinewavelike spectrum using only the reference clock [6], [9] [2]. Unless the generated frequency is an integer fraction of the clock, their output waveforms are irregular with high deterministic jitter and spectra full of strong frequency spurs, usually close to the carrier.…”

Section: Introductionmentioning

confidence: 99%

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All Digital Frequency Synthesis based on Pulse Direct Digital Synthesizer with spurs free output and improved noise floor

2014 IEEE International Frequency Control Symposium (FCS)

2014

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This work presents Direct-Digital Frequency Synthesis architectures based on the classical Pulse-Direct Digital Synthesizer and using two quantization paths with opposite dithers or multi-path quantization with independent dithers to achieve spurs-free output with improved dynamic range. The proposed architectures are studied mathematically and the theory is supported by MATLAB simulation results.

“…industry [1]- [3]. This was motivated by the increasing challenge in the design of R.F., analog and mixed-signal related circuit blocks, compared to alternative digital ones, as technologies downscale.…”

Section: Introductionmentioning

confidence: 99%

Dynamic range Vs spectral clarity trade-off in all-digital frequency synthesis via single-bit sinewave quantization

2013 Joint European Frequency and Time Forum &Amp; International Frequency Control Symposium (EFTF/IFC)

Stamatopoulos

2013

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Single-bit Nyquist-rate quantization of sinewaves with amplitude dithering using a sequence of independent and uniformly distributed random variables has been proposed for all-digital RF frequency synthesis generation. This work demonstrates how we can improve the Dynamic Range using non-uniformly distributed dithering by selectively allowing some of the harmonics to be present in the spectrum (vs. the spurs-free output of the uniform distribution.). MATLAB simulation examples illustrate the results of the proposed approach.