The Experts below are selected from a list of 192 Experts worldwide ranked by ideXlab platform

Lawrence Carin - One of the best experts on this subject based on the ideXlab platform.

  • resonances of perfectly conducting wires and Bodies of Revolution buried in a lossy dispersive half space
    IEEE Transactions on Antennas and Propagation, 1996
    Co-Authors: Stanislav Vitebskiy, Lawrence Carin
    Abstract:

    The method of moments (MoM) is utilized to compute the complex resonant frequencies and modal currents of perfectly conducting wires and Bodies of Revolution buried in a lossy dispersive half space. To make such an analysis tractable computationally, the half-space Green's function is computed via the method of complex images, with appropriate modifications made to account for the complex frequencies characteristic of resonant modes. Results are presented for wires and Bodies of Revolution buried in lossy soil using frequency-dependent measured parameters for the complex permittivity, and we demonstrate that the resonant frequencies generally vary with target depth. In addition to presenting results, relevant issues are addressed concerning the numerical computation of buried-target resonant frequencies.

  • short pulse plane wave scattering from buried perfectly conducting Bodies of Revolution
    IEEE Transactions on Antennas and Propagation, 1996
    Co-Authors: Stanislav Vitebskiy, K Sturgess, Lawrence Carin
    Abstract:

    The method of moments is used to analyze short-pulse plane-wave scattering from perfectly conducting Bodies of Revolution buried in a lossy, dispersive half space. The analysis is performed in the frequency domain, with the time-domain fields synthesized via Fourier transform. To make this analysis efficient, the method of complex images is used to compute the frequency-dependent components of the half-space dyadic Green's function. Results are presented for short-pulse scattering from buried spheres and cylinders, using measured frequency-dependent soil parameters (permittivity and conductivity).

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

  • electromagnetic scattering for multiple pec Bodies of Revolution using equivalence principle algorithm
    IEEE Transactions on Antennas and Propagation, 2014
    Co-Authors: Rushan Chen
    Abstract:

    An equivalence principle algorithm (EPA) method is extended to analyze the electromagnetic scattering from multiple Bodies of Revolution (MBoR) with the axes arbitrarily oriented. Equivalence spheres are used to enclose each BoR and the equivalence currents are expanded by the basis functions of Bodies of Revolution (BoR). To obtain the scattering operators and translation operators of EPA for Fourier modes independently, the rotational symmetry systems are established in local BoR coordinate systems. The origin of the local BoR coordinate system is located at the center of the equivalence sphere and the z-axis coincides with the axis of the enclosed BoR to obtain the scattering operator of each equivalence sphere, whereas the origin is located at the observation sphere and z-axis passes through the center of the source sphere to obtain the translation operator of each pair of equivalence spheres. The current coefficient transformation algorithm is used to transform the equivalence currents among local BoR coordinate systems. The total equation is iteratively solved in the global coordinate system. The proposed scheme is especially efficient for the analysis of scattering from MBoR randomly distributed in electrically large scale region. Numerical results are given to demonstrate the efficiency.

  • efficient analysis of em scattering from Bodies of Revolution via the aca
    IEEE Transactions on Antennas and Propagation, 2014
    Co-Authors: Dazhi Ding, Zhenhong Fan, Rushan Chen
    Abstract:

    In this communication, the adaptive cross approximation (ACA) algorithm is utilized to analyze the scattering from arbitrary metallic Bodies of Revolution (BoRs) that is formulated by the electric field integral equation approach. For a given mode, a multilevel partitioning is used to group the basis functions of the BoRs along the longitudinal dimension. The interactions of the adjacent groups are calculated directly by the method of moments (MoM), and the interactions of well-separated groups are compressed by the ACA algorithm. The memory requirement and CPU time consumption are reduced drastically.

  • Electromagnetic scattering of conducting Bodies of Revolution coated with chiral material
    2010 International Conference on Microwave and Millimeter Wave Technology, 2010
    Co-Authors: Jian Zhu, Rushan Chen
    Abstract:

    In this paper, the method of moment for Bodies of Revolution (BOR-MoM) is developed to analyze electromagnetic scattering from conducting Bodies of Revolution coated with chiral material. The Poggio-Miller-Chang-Harrington-Wu (PMCHW) integral equation is formulated using the surface equivalence principle, the boundary condition and Bohren's decomposition scheme, which is applied to split a chiral media into two equivalent homogeneous media. The usage of the axisymmetric property of the Bodies of Revolution can convert an original problem into a series problem with small-scale matrix equations, each of which is a Fourier mode of the method of moment for Bodies of Revolution; selecting suitable basis functions can reduce a three-dimensional problem to a two-dimensional one. Finally, numerical results demonstrate that the developed method of moment for Bodies of Revolution is valid and can greatly reduce the computational complexity.

Michael Oneil - One of the best experts on this subject based on the ideXlab platform.

  • a high order wideband direct solver for electromagnetic scattering from Bodies of Revolution
    Journal of Computational Physics, 2019
    Co-Authors: Charles L Epstein, Leslie Greengard, Michael Oneil
    Abstract:

    Abstract The generalized Debye source representation of time-harmonic electromagnetic fields yields well-conditioned second-kind integral equations for a variety of boundary value problems, including the problems of scattering from perfect electric conductors and dielectric Bodies. Furthermore, these representations, and resulting integral equations, are fully stable in the static limit as ω → 0 in multiply connected geometries. In this paper, we present the first high-order accurate solver based on this representation for Bodies of Revolution. The resulting solver uses a Nystrom discretization of a one-dimensional generating curve and high-order integral equation methods for applying and inverting surface differentials. The accuracy and speed of the solvers are demonstrated in several numerical examples.

  • a high order wideband direct solver for electromagnetic scattering from Bodies of Revolution
    arXiv: Numerical Analysis, 2017
    Co-Authors: Charles L Epstein, Leslie Greengard, Michael Oneil
    Abstract:

    The generalized Debye source representation of time-harmonic electromagnetic fields yields well-conditioned second-kind integral equations for a variety of boundary value problems, including the problems of scattering from perfect electric conductors and dielectric Bodies. Furthermore, these representations, and resulting integral equations, are fully stable in the static limit as $\omega \to 0$ in multiply connected geometries. In this paper, we present the first high-order accurate solver based on this representation for Bodies of Revolution. The resulting solver uses a Nystr\"om discretization of a one-dimensional generating curve and high-order integral equation methods for applying and inverting surface differentials. The accuracy and speed of the solvers are demonstrated in several numerical examples.

Stanislav Vitebskiy - One of the best experts on this subject based on the ideXlab platform.

  • resonances of perfectly conducting wires and Bodies of Revolution buried in a lossy dispersive half space
    IEEE Transactions on Antennas and Propagation, 1996
    Co-Authors: Stanislav Vitebskiy, Lawrence Carin
    Abstract:

    The method of moments (MoM) is utilized to compute the complex resonant frequencies and modal currents of perfectly conducting wires and Bodies of Revolution buried in a lossy dispersive half space. To make such an analysis tractable computationally, the half-space Green's function is computed via the method of complex images, with appropriate modifications made to account for the complex frequencies characteristic of resonant modes. Results are presented for wires and Bodies of Revolution buried in lossy soil using frequency-dependent measured parameters for the complex permittivity, and we demonstrate that the resonant frequencies generally vary with target depth. In addition to presenting results, relevant issues are addressed concerning the numerical computation of buried-target resonant frequencies.

  • short pulse plane wave scattering from buried perfectly conducting Bodies of Revolution
    IEEE Transactions on Antennas and Propagation, 1996
    Co-Authors: Stanislav Vitebskiy, K Sturgess, Lawrence Carin
    Abstract:

    The method of moments is used to analyze short-pulse plane-wave scattering from perfectly conducting Bodies of Revolution buried in a lossy, dispersive half space. The analysis is performed in the frequency domain, with the time-domain fields synthesized via Fourier transform. To make this analysis efficient, the method of complex images is used to compute the frequency-dependent components of the half-space dyadic Green's function. Results are presented for short-pulse scattering from buried spheres and cylinders, using measured frequency-dependent soil parameters (permittivity and conductivity).

Qing Huo Liu - One of the best experts on this subject based on the ideXlab platform.

  • a spectral integral method for smooth multilayered Bodies of Revolution
    IEEE Transactions on Antennas and Propagation, 2017
    Co-Authors: Weifeng Huang, Zaiping Nie, Qing Huo Liu
    Abstract:

    A spectral integral method (SIM) is developed to solve the scattering problem from smooth multilayered Bodies of Revolution (BoRs). This SIM is a spectral method to improve the accuracy and efficiency of the SIM by the fast Fourier transform (FFT) algorithm. This method can achieve high accuracy and greatly reduce the computational time consumption. In our BoR-SIM, the BoR generatrix current is expanded by the truncated Fourier series. Then, the impedance matrix is generated in the spectral domain to solve the scattering problem. Unlike the conventional methods that need eight to ten segments per wavelength, in the BoR-SIM, two points per wavelength are adequate to achieve high accuracy according to the Nyquist theorem. Being accelerated by FFT, this method shows a significant efficiency advantage over the conventional BoR method. Numerical results demonstrate the accuracy and efficiency of our new method. By combining with the Poggio–Miller–Chang–Harrington–Wu–Tsai surface integral equations, this method can be used to solve many practical scattering problems.

  • fast inhomogeneous plane wave algorithm for analysis of composite Bodies of Revolution
    Progress in Electromagnetics Research-pier, 2010
    Co-Authors: Xi Rui, Qing Huo Liu
    Abstract:

    A fast inhomogeneous plane wave algorithm is developed for the electromagnetic scattering problem from the composite Bodies of Revolution (BOR). Poggio-Miller-Chang-Harrington-Wu (PMCHW) approach is used for the homogeneous dielectric objects, while the electric fleld integral equation (EFIE) is used for the perfect electric conducting objects. The aggregation and disaggregation factors can be expressed analytically by using the Weyl identity. Compared with the traditional method of moments (MoM), both the memory requirement and CPU time, are reduced for large-scale composite BOR problems. Numerical results are given to demonstrate the validity and the e-ciency of the proposed method.