Digital High Order Multiplier-free Delta Sigma Modulator for Multistandard Fractional-N Frequency Synthesizer

This paper proposes a new stable design strategy for 1bit high order digital ∆Σ modulator for multistandard fractionalN frequency synthesizer. The proposed digital ∆Σ modulator presents simplicity, low power consumption and controls a dualmodulus divider instead of multi-modulus one as in existing ∆Σ fractional-N frequency synthesizer. Simulation results illustrate the ∆Σ modulator good performances in terms of spectrum purity and accuracy. Using this stable 1-bit digital ∆Σ modulator output to a fractional-N frequency synthesizer Simulink model verifies the multistandard frequency synthesizer specifications.