The Experts below are selected from a list of 117 Experts worldwide ranked by ideXlab platform

Yong Wang - One of the best experts on this subject based on the ideXlab platform.

  • design of Symmetric Window for thz traveling wave tube amplifier
    International Conference on Infrared Millimeter and Terahertz Waves, 2014
    Co-Authors: Chao Zhao, Yong Wang
    Abstract:

    This paper presents the analysis and design of the pill box input and output Windows for THz traveling-wave tube (TWT) amplifier. Both the theoretical mechanism and simulation results are analyzed. The simulation results clearly show a pass band 14 GHz of the Window as desired frequency. The results can provide a foundation on the fabricating of THz TWT amplifier.

  • Design of Symmetric Window for THz traveling-wave tube amplifier
    International Conference on Infrared Millimeter and Terahertz Waves IRMMW-THz, 2014
    Co-Authors: Xin Guo, Wenxin Liu, Chao Zhao, Yong Wang
    Abstract:

    The lifetime in a wireless network, in particular a wireless sensor network, depends strongly on the connectivity factor between nodes. Several factors can be at the origin of a connectivity rupture such as: lack of energy on a significant node level, infection of a vital node by a malevolent code and a logical or physical failure of a primary node. This rupture can lead in some cases to a reconfiguration of the network by generating a prejudicial overhead or in other cases to a failure of the mission assigned to the network. In this paper, we propose a DRFN approach (Detection and Replacement of a Failing Node) for the connectivity maintenance by carrying out a replacement chain according to a distributed algorithm. Through simulation, we have shown our approach efficiency. Compared with similar work, our proposed approach consumes less energy, and improves the percentage of reduction in field coverage. (C) 2013 Elsevier Ltd. All rights reserved.

Chao Zhao - One of the best experts on this subject based on the ideXlab platform.

  • design of Symmetric Window for thz traveling wave tube amplifier
    International Conference on Infrared Millimeter and Terahertz Waves, 2014
    Co-Authors: Chao Zhao, Yong Wang
    Abstract:

    This paper presents the analysis and design of the pill box input and output Windows for THz traveling-wave tube (TWT) amplifier. Both the theoretical mechanism and simulation results are analyzed. The simulation results clearly show a pass band 14 GHz of the Window as desired frequency. The results can provide a foundation on the fabricating of THz TWT amplifier.

  • Design of Symmetric Window for THz traveling-wave tube amplifier
    International Conference on Infrared Millimeter and Terahertz Waves IRMMW-THz, 2014
    Co-Authors: Xin Guo, Wenxin Liu, Chao Zhao, Yong Wang
    Abstract:

    The lifetime in a wireless network, in particular a wireless sensor network, depends strongly on the connectivity factor between nodes. Several factors can be at the origin of a connectivity rupture such as: lack of energy on a significant node level, infection of a vital node by a malevolent code and a logical or physical failure of a primary node. This rupture can lead in some cases to a reconfiguration of the network by generating a prejudicial overhead or in other cases to a failure of the mission assigned to the network. In this paper, we propose a DRFN approach (Detection and Replacement of a Failing Node) for the connectivity maintenance by carrying out a replacement chain according to a distributed algorithm. Through simulation, we have shown our approach efficiency. Compared with similar work, our proposed approach consumes less energy, and improves the percentage of reduction in field coverage. (C) 2013 Elsevier Ltd. All rights reserved.

Marek Blok - One of the best experts on this subject based on the ideXlab platform.

  • Variable Fractional Delay Filter Design Using a Symmetric Window
    Circuits Systems and Signal Processing, 2014
    Co-Authors: Marek Blok
    Abstract:

    In this paper a numerically efficient method for designing a nearly optimal variable fractional delay (VFD) filter based on a simple and well-known Window method is presented. In the proposed method a single Window extracted from the optimal filter with fixed fractional delay (FD) is divided into even and odd part. Subsequently, the odd part is discarded and Symmetric even part of the extracted Window is used to design a family of nearly optimal filters with varying FD. In addition to Window extraction, the proposed approach requires filter gain correction which is dependent on the desired FD. Optimum values of the gain correction factor as well as the extracted Window can be computed beforehand, which allows us to design a nearly optimal FD filter with arbitrary FD at low numerical costs during runtime. On the basis of the proposed filter design method, the universal structure of VFD filter allowing for change of filter type and length has been proposed. In the paper, three FD filter optimality criteria are considered, which are maximal flatness, Chebyshev (minimax), and least squares.

  • ECCTD - On practical aspects of optimal FSD filter design using extracted Window method
    2011 20th European Conference on Circuit Theory and Design (ECCTD), 2011
    Co-Authors: Marek Blok
    Abstract:

    In this paper the practical aspects of the extracted Window method applied to the nearly optimal fractional sample delay (FSD) filter design has been investigated. As the Window method is one of the most numerically efficient digital filter design methods, this approach is well suited for variable fractional sample delay (VFSD) filter implementations which require frequent impulse response recalculation. On the other hand, the use of Symmetric Window extracted from the optimal filter (minimax or least squared error) solves the problem of Window selection and results in nearly optimal high performance VFSD filters. However, the design procedure requires additional gain correction dependent on fractional delay. As the optimal gain correction factor computation should not be performed at runtime, low order polynomial approximation has been investigated in this paper. Additionally, performance loss resulting from limited word length in fixed-point arithmetic has also been discussed.

  • Gain correction for nearly optimal variable fractional sample delay filter design
    2011
    Co-Authors: Marek Blok
    Abstract:

    One of the most numerically efficient digital filter design methods is the Window method. This makes the Window approach well suited for variable fractional sample delay (VFSD) filter implementation which requires frequent impulse response recalculation. On the other hand, if high performance filters are required, Window selection is usually problematic. That is why the use of Symmetric Window extracted from the optimal filter is investigated in this paper. Such single Window, extracted for some arbitrary delay, can be used to implement nearly optimal VFSD filter. However, with the delay change the gain of the designed filter changes too, which significantly deteriorates filter performance and must be corrected. As we have demonstrated, the proper gain correction leads to nearly optimal FSD filter design allowing for nearly optimal numerically efficient implementation of VFSD filter. Two cases for different optimality criteria, minimax (Chebyshev) and least squared error, have been discussed in this paper.

Dario Petri - One of the best experts on this subject based on the ideXlab platform.

  • Spectral Estimation of Wideband Noise in
    2020
    Co-Authors: E. Nunzi, Paolo Carbone, Dario Petri
    Abstract:

    Spectral leakage is a well-known phenomenon in- duced by the Windowing process and usually revealed in the frequency domain. Scientific literature has deeply investigated the spectral leakage of narrow-band components. However, the problem of Windowing a wide-band colored noise has not yet been fully characterized. In this paper, the effect of the Windowing process on the estimate of the in-band ∆Σ-shaped quantization- noise power spectral density is investigated. The reported analysis holds for any modulator order and for any kind of real and Symmetric Window and proves the necessity of the Windowing process in order to reduce the in-band noise power estimation bias. Moreover, an ap rioricriterion for designing the optimal Window that reduces the shaped-noise spectral leakage and for choosing the minimum number of acquired samples to be employed is derived.

  • Spectral Estimation of Wideband Noise in Delta–Sigma Modulators
    IEEE Transactions on Instrumentation and Measurement, 2006
    Co-Authors: E. Nunzi, Paolo Carbone, Dario Petri
    Abstract:

    Spectral leakage is a well-known phenomenon induced by the Windowing process and usually revealed in the frequency domain. Scientific literature has deeply investigated the spectral leakage of narrow-band components. However, the problem of Windowing a wide-band colored noise has not yet been fully characterized. In this paper, the effect of the Windowing process on the estimate of the in-band DeltaSigma-shaped quantization-noise power spectral density is investigated. The reported analysis holds for any modulator order and for any kind of real and Symmetric Window and proves the necessity of the Windowing process in order to reduce the in-band noise power estimation bias. Moreover, an a priori criterion for designing the optimal Window that reduces the shaped-noise spectral leakage and for choosing the minimum number of acquired samples to be employed is derived

  • Spectral Estimation of Wide-band Noise in Delta-Sigma Modulators
    2005 IEEE Instrumentationand Measurement Technology Conference Proceedings, 2005
    Co-Authors: E. Nunzi, R. Carbone, Dario Petri
    Abstract:

    Spectral leakage is a well-known phenomenon induced by the Windowing process and usually revealed in the frequency domain. Scientific literature has deeply investigated the spectral leakage of narrow-band components. However, the problem of Windowing a wide-band colored noise has not been fully characterized, yet. In this paper the effect of the Windowing process on the estimate of the in-band DeltaSigma -shaped-quantization noise power spectral density (PSD) is investigated. The reported analysis holds for any modulator order and for any kind of real and Symmetric Window. Moreover, an a-priori criterion for designing optimal Window that reduces shaped noise spectral leakage and for choosing the minimum number of acquired samples to be employed is derived

Xin Guo - One of the best experts on this subject based on the ideXlab platform.

  • Design of Symmetric Window for THz traveling-wave tube amplifier
    International Conference on Infrared Millimeter and Terahertz Waves IRMMW-THz, 2014
    Co-Authors: Xin Guo, Wenxin Liu, Chao Zhao, Yong Wang
    Abstract:

    The lifetime in a wireless network, in particular a wireless sensor network, depends strongly on the connectivity factor between nodes. Several factors can be at the origin of a connectivity rupture such as: lack of energy on a significant node level, infection of a vital node by a malevolent code and a logical or physical failure of a primary node. This rupture can lead in some cases to a reconfiguration of the network by generating a prejudicial overhead or in other cases to a failure of the mission assigned to the network. In this paper, we propose a DRFN approach (Detection and Replacement of a Failing Node) for the connectivity maintenance by carrying out a replacement chain according to a distributed algorithm. Through simulation, we have shown our approach efficiency. Compared with similar work, our proposed approach consumes less energy, and improves the percentage of reduction in field coverage. (C) 2013 Elsevier Ltd. All rights reserved.