The Experts below are selected from a list of 3393 Experts worldwide ranked by ideXlab platform

De Pelecijn Elly - One of the best experts on this subject based on the ideXlab platform.

  • High speed time-multiplexed continuous time Sigma-Delta Converters
    IEEE, 2017
    Co-Authors: De Pelecijn Elly
    Abstract:

    This paper presents a time-interleaved continuous time Sigma-Delta Converter, which uses 4 identical channels clocked at equally shifted time moments of a 4 GHz clock. The data in each channel is filtered and afterwards recombined in a multiplexer, leading to an output signal at 4 GHz before decimation. Time-interleaving as proposed in this paper makes it possible to increase the signal-to-noise and distortion ratio (SNDR) in a specified bandwidth with 3 dB every time the number of channels is doubled. By exchanging the gain in accuracy for bandwidth, a high-speed Sigma-Delta Converter with 250 MHz signal bandwidth and 65 dB SNDR is obtained in simulations. The simulated Converter achieves a dynamic range of 72 dB and consumes 626 mW, leading to a Schreier FOM of 158 dB and a Walden FOM of 864.5 fJ/conv. This paper briefly discusses the different building blocks of the interleaved Converter and their influence on the performance.status: publishe

  • High Speed Time-multiplexed Continuous Time Sigma-Delta Converters
    'Institute of Electrical and Electronics Engineers (IEEE)', 2017
    Co-Authors: De Pelecijn Elly, Tavernier Filip, Steyaert Michiel
    Abstract:

    © 2017 IEEE. This paper presents a time-interleaved continuous time Sigma-Delta Converter, which uses 4 identical channels clocked at equally shifted time moments of a 4 GHz clock. The data in each channel is filtered and afterwards recombined in a multiplexer, leading to an output signal at 4 GHz before decimation. Time-interleaving as proposed in this paper makes it possible to increase the signal-to-noise and distortion ratio (SNDR) in a specified bandwidth with 3 dB every time the number of channels is doubled. By exchanging the gain in accuracy for bandwidth, a high-speed Sigma-Delta Converter with 250 MHz signal bandwidth and 65 dB SNDR is obtained in simulations. The simulated Converter achieves a dynamic range of 72 dB and consumes 626 mW, leading to a Schreier FOM of 158 dB and a Walden FOM of 864.5 fJ/conv. This paper briefly discusses the different building blocks of the interleaved Converter and their influence on the performance.status: publishe

Hannu Tenhunen - One of the best experts on this subject based on the ideXlab platform.

  • a method for stability and performance analysis of low oversampling ratio higher order Sigma Delta noise shaper architectures
    Midwest Symposium on Circuits and Systems, 1999
    Co-Authors: A Gothenberg, Hannu Tenhunen
    Abstract:

    This paper demonstrates a method for determining the stability and sensitivity of feedback coefficient variations of Sigma Delta noise shapers using a model based on parameterized quantization gain which varies from sample to sample. The method is demonstrated for two types of Sigma Delta Converter structures, the 4th order multibit cascaded structure and the 5th order single stage 1-bit structure.

  • performance analysis of low oversampling ratio Sigma Delta noise shapers for rf applications
    International Symposium on Circuits and Systems, 1998
    Co-Authors: A Gothenberg, Hannu Tenhunen
    Abstract:

    Baseband signal processing for current base stations or 3rd generation mobile systems will impose high bandwidth and high VLSI integration demand. Many of the desired integration aspects can be satisfied with Sigma-Delta Converter front-ends. However, under the technology constraints there are simultaneous requirements for high sample rate and low oversampling ratio in order to achieve the desired baseband width. In this paper, we present system architecture results for 4th-order cascaded noise shaper architectures for baseband front-ends and show that the cascaded structures with proper scaling will satisfy simultaneous demand on linearity (spurious free dynamic range) and high SQNR with low oversampling ratio based on usage of multibit quantizers outside the actual signal noise shaping path.

Steyaert Michiel - One of the best experts on this subject based on the ideXlab platform.

  • High Speed Time-multiplexed Continuous Time Sigma-Delta Converters
    'Institute of Electrical and Electronics Engineers (IEEE)', 2017
    Co-Authors: De Pelecijn Elly, Tavernier Filip, Steyaert Michiel
    Abstract:

    © 2017 IEEE. This paper presents a time-interleaved continuous time Sigma-Delta Converter, which uses 4 identical channels clocked at equally shifted time moments of a 4 GHz clock. The data in each channel is filtered and afterwards recombined in a multiplexer, leading to an output signal at 4 GHz before decimation. Time-interleaving as proposed in this paper makes it possible to increase the signal-to-noise and distortion ratio (SNDR) in a specified bandwidth with 3 dB every time the number of channels is doubled. By exchanging the gain in accuracy for bandwidth, a high-speed Sigma-Delta Converter with 250 MHz signal bandwidth and 65 dB SNDR is obtained in simulations. The simulated Converter achieves a dynamic range of 72 dB and consumes 626 mW, leading to a Schreier FOM of 158 dB and a Walden FOM of 864.5 fJ/conv. This paper briefly discusses the different building blocks of the interleaved Converter and their influence on the performance.status: publishe

A Gothenberg - One of the best experts on this subject based on the ideXlab platform.

  • a method for stability and performance analysis of low oversampling ratio higher order Sigma Delta noise shaper architectures
    Midwest Symposium on Circuits and Systems, 1999
    Co-Authors: A Gothenberg, Hannu Tenhunen
    Abstract:

    This paper demonstrates a method for determining the stability and sensitivity of feedback coefficient variations of Sigma Delta noise shapers using a model based on parameterized quantization gain which varies from sample to sample. The method is demonstrated for two types of Sigma Delta Converter structures, the 4th order multibit cascaded structure and the 5th order single stage 1-bit structure.

  • performance analysis of low oversampling ratio Sigma Delta noise shapers for rf applications
    International Symposium on Circuits and Systems, 1998
    Co-Authors: A Gothenberg, Hannu Tenhunen
    Abstract:

    Baseband signal processing for current base stations or 3rd generation mobile systems will impose high bandwidth and high VLSI integration demand. Many of the desired integration aspects can be satisfied with Sigma-Delta Converter front-ends. However, under the technology constraints there are simultaneous requirements for high sample rate and low oversampling ratio in order to achieve the desired baseband width. In this paper, we present system architecture results for 4th-order cascaded noise shaper architectures for baseband front-ends and show that the cascaded structures with proper scaling will satisfy simultaneous demand on linearity (spurious free dynamic range) and high SQNR with low oversampling ratio based on usage of multibit quantizers outside the actual signal noise shaping path.

Bosco Leung - One of the best experts on this subject based on the ideXlab platform.

  • quantization noise spectrum of double loop Sigma Delta Converter with sinusoidal input
    IEEE Transactions on Circuits and Systems Ii: Analog and Digital Signal Processing, 1994
    Co-Authors: Sundeep Rangan, Bosco Leung
    Abstract:

    An exact formula for the output noise spectrum of a double-loop Sigma-Delta modulator, under the no overloading assumption and with a sinusoidal input, is derived without the use of a white-noise model. In the case of a sinusoidal input with irrational input amplitude and digital frequency, the result agrees with the exact formula derived by ergodic theory for two-stage modulators. In addition, the present method also provides an exact formula for sinusoidal inputs with rational frequency and amplitude. Furthermore, the period of the output with rational initial conditions and DC input is also calculated. The results are of primary interest to multibit Sigma-Delta modulators, which do not overload over the entire input amplitude range. The ergodic theory method for calculating the exact noise spectrum involves explicitly determining the autocorrelation of the internal quantization error with ergodic theory techniques, and then determining the noise spectrum from the correlation function. The present method, however, directly determines the quantization noise spectrum by using an open-loop model for the coder and applying a Fourier series representation of the quantization error function. The result of both of these methods is that the output noise spectrum for a sinusoidal input is composed of discrete spectral lines shaped by a sin /sup 4/(w/2) envelope. >

  • quantization noise spectrum of double loop Sigma Delta Converter with sinusoidal input
    Midwest Symposium on Circuits and Systems, 1993
    Co-Authors: Sundeep Rangan, Bosco Leung
    Abstract:

    An exact formula for the output noise spectrum of a double-loop Sigma-Delta modulator with a sinusoidal input is derived without the use of a white-noise model. In the case of a sinusoidal input with irrational input amplitude and digital frequency, the result agrees with the exact formula derived by ergodic theory for two-stage modulators. In addition, the present method also provides an exact formula for a sinusoidal input with rational frequency and amplitude. Furthermore, the period of the output with rational initial conditions and DC input is also calculated. All results assume that the quantizer does not overload, and hence apply only to multi-bit coders. The ergodic theory method for calculating the exact noise spectrum involves explicitly determining the autocorrelation of the internal quantization error with ergodic theory techniques, and then determining the noise spectrum from the correlation function. The present method, however, directly determines the quantization noise spectrum by using an open-loop model for the coder and applying a Fourier series representation of the quantization error function. The result of both of these methods is that the output noise spectrum for a sinusoidal input is composed of discrete spectral lines shaped by a sin/sup 4/(/spl omega2) envelope. >