The Experts below are selected from a list of 318 Experts worldwide ranked by ideXlab platform

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

Tapan K. Sarkar - One of the best experts on this subject based on the ideXlab platform.

  • Generation of nonminimum phase and time Domain Response using amplitude-only data
    2016 International Conference on Electromagnetics in Advanced Applications (ICEAA), 2016
    Co-Authors: Tapan K. Sarkar, Magdalena Salazar
    Abstract:

    A method is presented for the generation of nonminimum phase from amplitude — only data. The nonminimum phase is generated utilizing the principles of causality and the Hilbert transform. The application of the theory has been applied to some antenna radiation-power patterns and to measured transfer functions of microwave filters to illustrate the applicability of this approach. Once the phase Response is obtained a time Domain Response of the system can be generated using amplitude only data.

  • Accurate Interpolation of Amplitude-Only Frequency Domain Response Based on an Adaptive Cauchy Method
    IEEE Transactions on Antennas and Propagation, 2016
    Co-Authors: Jie Yang, Tapan K. Sarkar
    Abstract:

    In this paper, a fast and accurate interpolation algorithm is proposed to reconstruct the high resolution amplitude only frequency Domain Response such as radar cross section and antenna radiation patterns from sparse and nonuniform samples based on the Cauchy method. For the Cauchy method, the amplitude only system frequency Response is represented by a ratio of two polynomials, whose coefficients are estimated by using the conjunction of total least square (TLS) methodology, singular value decomposition (SVD) and conjugate gradient methods. Nonuniform sampling is implemented in Cauchy method such that any additional samples and any a priori information can be added to the existing sample set to continuously improve the interpolation result. In this proposed algorithm, the sample set is automatically adjusted according to the nature of the given data, so that the computational load is minimized by taking the least number of sample points while still maintaining high interpolation accuracy. Even though the Cauchy method can accurately interpolate the data containing both amplitude and phase, in this paper, the application is illustrated for the interpolation of amplitude only data, which may not be differentiable at all points.

  • Reconstruction of the time Domain Response of a CRLH transmission line using analytic continuation
    2013 IEEE Antennas and Propagation Society International Symposium (APSURSI), 2013
    Co-Authors: Walid M. Dyab, Tapan K. Sarkar, Mohammad N. Abdallah, Magdalena Salazar-palma
    Abstract:

    In this paper, the principle of analytic continuation is applied to reconstruct the time Domain Response of the so called Composite Right-Left Handed (CRLH) transmission line. The reconstruction is achieved from a wideband frequency Domain measurement. The principle of analytic continuation enforces the causality of the reconstructed Response. Hence, the problem of temporal leakage due to ringing can be totally eliminated, and the measurement error can be reduced. The reconstructed time Domain Response can be used to examine the true characteristics of the CRLH transmission lines.

  • Time Reversal Applied to the Time Domain Response of a CRLH Transmission Line
    IEEE Microwave and Wireless Components Letters, 2012
    Co-Authors: Walid M. Dyab, Tapan K. Sarkar, Magdalena Salazar-palma
    Abstract:

    In this letter, the concept of electromagnetic time reversal is applied to compensate for the non-linear phase Response of a dispersive transmission line. To achieve a significant phase distortion on a short transmission line, a special type of transmission lines is chosen as an experimental platform. This special type is the so called composite right-left handed (CRLH) transmission line. The time Domain Response of the CRLH transmission line is calculated from a wideband frequency Domain measurement.

  • Evaluation of a Causal Time Domain Response from Bandlimited Frequency Domain Data
    Ultra-Wideband Short-Pulse Electromagnetics, 1993
    Co-Authors: Tapan K. Sarkar, H. Wang, Raviraj S. Adve, M. Moturi, Michael C. Wicks
    Abstract:

    Broadband measurements may be performed in either the time Domain or the frequency Domain. Time Domain measurements are easier to perform since the waveforms of interest are all real However, one disadvantage is the limited dynamic range of available systems, whereas frequency Domain measurement equipment benefits from large dynamic range. Also, it is difficult to recover the true time Domain Response from measurements made in a noisy environment. On the other hand, frequency Domain measurements maybe carried out either over an entire range of frequencies or selectively over a band of frequencies, whichever is convenient and/or less susceptible to noise. From these measurements a time Domain Response can be extracted by an inverse Fourier transform. Since, bandlimited complex frequency Domain data does not guarantee causality in the time Domain, nor a real time Domain Response, measurements carried out in the frequency Domain do not truly represent the transient Response of the system.

J.r. Griffith - One of the best experts on this subject based on the ideXlab platform.

  • Time-Domain analysis of lossy coupled transmission lines
    IEEE Transactions on Microwave Theory and Techniques, 1990
    Co-Authors: J.r. Griffith
    Abstract:

    A novel method based on numerical inversion of the Laplace transform is presented for the analysis of lossy coupled transmission lines with arbitrary linear terminal and interconnecting networks. The formulation of the network equations is based on a Laplace-Domain admittance stamp for the transmission line. The transmission line stamp can be used to formulate equations representing arbitrarily complex networks of transmission lines and interconnects. These equations can be solved to get the frequency-Domain Response of the network. Numerical inversion of the Laplace transform allows the time-Domain Response to be calculated directly from Laplace-Domain equations. This method is an alternative to calculating the frequency-Domain Response and using the fast Fourier transform to obtain the time-Domain Response. The inversion technique is equivalent to high-order, numerically stable integration methods. Numerical examples showing the general application of the method are presented. It is shown that the inverse Laplace technique is able to calculate the step Response of a network. The time-Domain independence of the solution is exploited by an efficient calculation of the propagation delay of the network.

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

Xiaoke Chen - One of the best experts on this subject based on the ideXlab platform.

  • The Time-Domain Response for the Lossy Transmission Line by Precise Integration Method
    2019 12th International Congress on Image and Signal Processing BioMedical Engineering and Informatics (CISP-BMEI), 2019
    Co-Authors: Xiaoke Chen, Jinquan Zhao, Jing Xu
    Abstract:

    The precise time-integration method is introduced into the time-Domain Response analysis of transmission lines. This method is a particularly fast and accurate explicit time-integration format with unconditionally stable, which can be used in large steps, which is superior to the commonly used FFT and NILT methods in terms of accuracy, efficiency and function. Also, we present the calculation example at the end of the article.

  • CISP-BMEI - A precise time-integration for analysis of time-Domain Response to lossy transmission lines
    2016 9th International Congress on Image and Signal Processing BioMedical Engineering and Informatics (CISP-BMEI), 2016
    Co-Authors: Xiaoke Chen, Jie Zeng, Jinquan Zhao, Zhuo Wang
    Abstract:

    The precise integration method is a semi analytical solution method of partial differential equation method. Based on the precise integration method, the lossy transmission line transient Response analysis method is a time Domain analysis method. The lossy transmission line transient Response analysis method can easily deal with the transmission line problems, which is difficult for the nonzero initial value and nonlinear load frequency Domain method to deal with, but it is still difficult to deal with the reactance load of transmission line. By separating and integrating the beginning and terminal conditions of the precise integration method, and introducing time Domain adjoint model of the various kinds of load, this paper solves the problems of the load reactance of transmission line, also solves the transmission line problems of long time transition, short circuit and open circuit, which greatly improves the precise integration method for the analysis of the efficacy of transmission lines in time Domain Response. Finally, the correctness of the presented method is illustrated by the application examples, which provide a theoretical basis for the time Domain analysis of the transient Response of the transmission line.

  • ICNC-FSKD - Sensitivity analysis for time Domain Response of transmission lines based on the precise integration method
    2016 12th International Conference on Natural Computation Fuzzy Systems and Knowledge Discovery (ICNC-FSKD), 2016
    Co-Authors: Xiaoke Chen, Jie Zeng, Hao Zhou, Jinquan Zhao, Xuemin Wang
    Abstract:

    Since the sensitivity analysis method for time Domain Response of transmission lines based on the frequency Domain method is difficult to handle with the sensitivity problem of transient Response of transmission lines, a novel method based on the precise computation method is described for the sensitivity analysis for time Domain Response of transmission lines in this paper. By the difference divergence of space of telegraph equations in time Domain to construct the first-order differential equation of transient Response of transmission lines and sensitivity of transient Response of transmission lines to time, it uses precise integration method to analyze the sensitivity of Response in time Domain directly. It's a semi-analytical method in time Domain which is simple, accurate and stable. It can handle with the sensitivity of time Domain Response of transmission lines with arbitrary terminal loads, boundary conditions and transmitted signals. Finally, the application example proves the correctness of method in this paper.

  • Sensitivity analysis for time Domain Response of transmission lines based on the precise integration method
    2016 12th International Conference on Natural Computation Fuzzy Systems and Knowledge Discovery (ICNC-FSKD), 2016
    Co-Authors: Xiaoke Chen, Jie Zeng, Hao Zhou, Jinquan Zhao, Xuemin Wang
    Abstract:

    Since the sensitivity analysis method for time Domain Response of transmission lines based on the frequency Domain method is difficult to handle with the sensitivity problem of transient Response of transmission lines, a novel method based on the precise computation method is described for the sensitivity analysis for time Domain Response of transmission lines in this paper. By the difference divergence of space of telegraph equations in time Domain to construct the first-order differential equation of transient Response of transmission lines and sensitivity of transient Response of transmission lines to time, it uses precise integration method to analyze the sensitivity of Response in time Domain directly. It's a semi-analytical method in time Domain which is simple, accurate and stable. It can handle with the sensitivity of time Domain Response of transmission lines with arbitrary terminal loads, boundary conditions and transmitted signals. Finally, the application example proves the correctness of method in this paper.

  • A precise time-integration for analysis of time-Domain Response to lossy transmission lines
    2016 9th International Congress on Image and Signal Processing BioMedical Engineering and Informatics (CISP-BMEI), 2016
    Co-Authors: Xiaoke Chen, Jie Zeng, Jinquan Zhao, Zhuo Wang
    Abstract:

    The precise integration method is a semi analytical solution method of partial differential equation method. Based on the precise integration method, the lossy transmission line transient Response analysis method is a time Domain analysis method. The lossy transmission line transient Response analysis method can easily deal with the transmission line problems, which is difficult for the nonzero initial value and nonlinear load frequency Domain method to deal with, but it is still difficult to deal with the reactance load of transmission line. By separating and integrating the beginning and terminal conditions of the precise integration method, and introducing time Domain adjoint model of the various kinds of load, this paper solves the problems of the load reactance of transmission line, also solves the transmission line problems of long time transition, short circuit and open circuit, which greatly improves the precise integration method for the analysis of the efficacy of transmission lines in time Domain Response. Finally, the correctness of the presented method is illustrated by the application examples, which provide a theoretical basis for the time Domain analysis of the transient Response of the transmission line.