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Spur reduction technique for fractional-N frequency synthesizer with MASH 1-1-1-1 Sigma Delta modulator

Publication Type : Conference Paper

Publisher : 2014 International Conference on Communication and Signal Processing

Source : 2014 International Conference on Communication and Signal Processing (2014)

Url : https://ieeexplore.ieee.org/abstract/document/6949973/

Keywords : closed loop system, Comb filter, Comb filters, Detectors, Feedback, fourth order MASH sigma delta modulator, fractional feedback, fractional-N frequency synthesizer, frequency 2 MHz, frequency 20 MHz, frequency 200 MHz to 220 MHz, frequency modulation, Frequency synthesizers, gain 6.02 dB, lead, MASH sigma delta modulator, Matlab-Simulink macromodel, noise, noise shaping, notch filters, notch type Comb filter, Phase frequency detector, Quantization (signal), reference input, sigma-delta modulation, spur reduction technique, Spurs, time 3.32 mus, Time-frequency analysis

Campus : Bengaluru

School : School of Engineering

Department : Electronics and Communication

Verified : No

Year : 2014

Abstract : A fourth order MASH Sigma Delta modulator based fractional-N frequency synthesizer was designed and validated as a Matlab/Simulink macro- model. Use of MASH achieves a better noise shaping for the frequencies generated by the synthesizer. With a reference frequency of 20MHz, the fractional-N frequency synthesizer achieves a synthesized frequency range of 200MHz to 220MHz with 2 MHz resolution. The macro-model has a gain margin of 6.02dB and a phase margin of 39.7°, ensuring the stability of the closed loop system with settling time of 3.32μ sec. Spurs that were introduced by the fractional feedback and reference input are removed through notch type Comb filter.

Cite this Research Publication : T. V, P. Maran, and Premanand Venkatesh Chandramani, “Spur reduction technique for fractional-N frequency synthesizer with MASH 1-1-1-1 Sigma Delta modulator”, in 2014 International Conference on Communication and Signal Processing, 2014.

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