• DocumentCode
    2735159
  • Title

    Complex bandpass ΣΔAD modulator with noise-coupled architecture

  • Author

    San, Hao ; Kobayashi, Hideo

  • Author_Institution
    Dept. of Electron. Eng., Gunma Univ., Kiryu
  • fYear
    2008
  • fDate
    10-13 Aug. 2008
  • Firstpage
    486
  • Lastpage
    489
  • Abstract
    Complex bandpass DeltaSigmaAD modulators can provide superior performance to a pair of real bandpass DeltaSigmaAD modulators of the same order. They process just input I and Q signals, not image signals, and AD conversion can be realized with low power dissipation, so that they are desirable for such low-IF receiver applications. This paper proposes a new architecture for complex bandpass DeltaSigmaAD modulators with noise-coupled topology, which effectively raises the order of the complex modulator and achieves higher SQNDR (Signal to Quantization Noise and Distortion Ratio) with low power dissipation. By providing the cross-coupled quantization noise injection to internal I and Q Paths, two quantizerspsila noise coupling can be realized in complex form, which enhances the order of noise shaping in complex domain, and provides a higher-order NTF using a lower-order loop filter in complex DeltaSigmaAD modulator. Proposed higher-order modulator can be realized just by adding some passive capacitors and switches, the additional integrator circuit composed of operation amplifier is not necessary, and the performance of the complex modulator can be effectively raised without more power dissipation. We have performed simulation with MATLAB to verify the effectiveness of the proposed architecture. The simulation results show that the proposed architecture can achieve the realization of higher-order enhancement, and improve the SQNDR of a complex bandpass DeltaSigmaAD modulator.
  • Keywords
    analogue-digital conversion; delta-sigma modulation; integrating circuits; AD conversion; complex bandpass SigmaDeltaAD modulator; cross-coupled quantization noise injection; higher-order modulator; integrator circuit; loop filter; low-IF receiver applications; noise coupling; noise shaping; noise-coupled architecture; noise-coupled topology; operation amplifier; passive capacitors; passive switches; Circuit simulation; Delta modulation; Distortion; Image converters; Noise shaping; Power dissipation; Quantization; Signal processing; Signal to noise ratio; Topology;
  • fLanguage
    English
  • Publisher
    ieee
  • Conference_Titel
    Circuits and Systems, 2008. MWSCAS 2008. 51st Midwest Symposium on
  • Conference_Location
    Knoxville, TN
  • ISSN
    1548-3746
  • Print_ISBN
    978-1-4244-2166-4
  • Electronic_ISBN
    1548-3746
  • Type

    conf

  • DOI
    10.1109/MWSCAS.2008.4616842
  • Filename
    4616842