WestminsterResearch

Methods for the transfer function design of multiple narrow-band bandpass sigma-delta modulators

Al-Janabi, Mohammed and Kale, Izzet and Morling, Richard C.S. (2001) Methods for the transfer function design of multiple narrow-band bandpass sigma-delta modulators. Computer Standards & Interfaces, 23 (2). pp. 85-102. ISSN 0920-5489

Full text not available from this repository.

Official URL: http://dx.doi.org/10.1016/S0920-5489(01)00062-9

Abstract

This paper presents the design analysis of novel tunable narrow-band bandpass sigma-delta modulators, which can achieve concurrent multiple noise-shaping for multi-tone input signals. Four different design methodologies based on the noise transfer functions of comb filters, slink filters, multi-notch filters and fractional delay comb filters are applied for the design of these multiple-band sigma-delta modulators. The latter approach utilises conventional comb filters in conjunction with FIR, or allpass IIR fractional delay filters, to deliver the desired nulls for the quantisation noise transfer function. Detailed simulation results show that FIR fractional delay comb filter-based sigma-delta modulators tune accurately to most centre frequencies, but suffer from degraded resolution at frequencies close to Nyquist. However, superior accuracies are obtained from their allpass IIR fractional delay counterpart at the expense of a slight shift in noise-shaping bands at very high frequencies. The merits and drawbacks of each technique for the various sigma-delta topologies are assessed in terms of in-band signal-to-noise ratios, accuracy of tunability and coefficient complexity for ease of implementation.

Item Type:Article
Uncontrolled Keywords:Bandpass sigma-delta modulation, Multi-notch filters, Comb filters, Slink filters, Fractional-delay filters
Research Community:University of Westminster > Electronics and Computer Science, School of
ID Code:900
Deposited On:01 Dec 2005
Last Modified:15 Oct 2009 12:17

Repository Staff Only: item control page