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

2015 IEEE International Symposium on Circuits and Systems (ISCAS)

2015

Self Cite

“…In this case it can be shown [13][14] 3.01 DR f s = − dB [13]. Note that the dynamic range observed in Fig.…”

Section: Introductionmentioning

confidence: 78%

“…Here M dithering and quantization paths following the LUT, with mutually independent, IID and uniformly distributed in [ ] ( ) 10 10 log M dB compared to that of Fig. 3, [13].…”

Section: Enhancing the Dynamic Rangementioning

confidence: 99%

Spurs-free single-bit-output frequency synthesizers for fully-digital RF transmitters

2015 IEEE International Symposium on Circuits and Systems (ISCAS)

2015

Self Cite

“…The problem of generating spurious-free output with a dithered PDDS has been studied in abstract form in [9]. It is shown that random dithering having appropriate statistics results in spurs-free output [9]- [11]. However, in some sense, dithering converts the frequency spurs into a noise floor.…”

Section: Forward Architecturesmentioning

confidence: 99%

“…5 [11]. The output is spurs-free and the DR, defined as the ratio of the power of the desirable signal to the power spectral density (PSD) of the near-in noise s e is DR = 10 log 10 (f s ) − 3.01 dB, (in the continuous time-domain) [10], [11].…”

Section: A Eliminating Spurs With Ditheringmentioning

confidence: 99%

Spurs-Free Single-Bit-Output All-Digital Frequency Synthesizers With Forward and Feedback Spurs and Noise Cancellation

IEEE Trans. Circuits Syst. I

2016

Self Cite

All-digital frequency synthesis architectures with phase and polar Σ-Δ modulation feedback loops are introduced as a means to overcome the inherent spectral-quality limitations of forward-dithered all-digital frequency synthesizers represented by the family of pulse direct digital synthesizers. The spectrum of dithered pulse direct digital synthesizers is derived first, with and without modulation, as well as that of their variations with multiple dithered paths and with colored dithering resulting in lower noise level. The limited dynamic range achieved by forwarddithered all-digital frequency synthesizers motivates the introduction of phase and polar Σ-Δ modulation feedback loop architectures which are modeled and analyzed to derive their noise transfer functions. Extensive MATLAB simulation illustrates the suppressed near-in noise and the high spurs-free dynamic range the two Σ-Δ schemes can achieve and the wideband spurs-free output of the polar one. Detailed analysis and implementation aspects of the techniques are outside the scope of the paper.Index Terms-Digital signal processing, digital-to-analog converter, digital-to-frequency converter, direct digital synthesis, feedback loop, filter, frequency spurs, noise shaping, quantization, spectrum, stability. 1549-8328

“…use of colored random sequences, (without feedback) can improve the dynamic range but not a lot [4][5].…”

Section: Introductionmentioning

confidence: 99%

All digital frequency synthesis based on new sigma-delta modulation architectures

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

2015

Self Cite