The Experts below are selected from a list of 324 Experts worldwide ranked by ideXlab platform

Wenhua Su - One of the best experts on this subject based on the ideXlab platform.

  • theoretical models for ultrashort Electromagnetic Pulse propagation in nonlinear metamaterials
    Physical Review A, 2007
    Co-Authors: Yuanjiang Xiang, Zhixiang Tang, Wenhua Su
    Abstract:

    A metamaterial (MM) differs from an ordinary optical material mainly in that it has a dispersive magnetic permeability and offers greatly enhanced design freedom to alter the linear and nonlinear properties. This makes it possible for us to control the propagation of ultrashort Electromagnetic Pulses at will. Here we report on generic features of ultrashort Electromagnetic Pulse propagation and demonstrate the controllability of both the linear and nonlinear parameters of models for Pulse propagation in MMs. First, we derive a generalized system of coupled three-dimensional nonlinear Schroedinger equations (NLSEs) suitable for few-cycle Pulse propagation in a MM with both nonlinear electric polarization and nonlinear magnetization. The coupled equations recover previous models for Pulse propagation in both ordinary material and a MM under the same conditions. Second, by using the coupled NLSEs in the Drude dispersive model as an example, we identify the respective roles of the dispersive electric permittivity and magnetic permeability in ultrashort Pulse propagation and disclose some additional features of Pulse propagation in MMs. It is shown that, for linear propagation, the sign and magnitude of space-time focusing can be controlled through adjusting the linear dispersive permittivity and permeability. For nonlinear propagation, the linear dispersive permittivity and permeabilitymore » are incorporated into the nonlinear magnetization and nonlinear polarization, respectively, resulting in controllable magnetic and electric self-steepening effects and higher-order dispersively nonlinear terms in the propagation models.« less

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

  • self induced transparency and Electromagnetic Pulse compression in a plasma or an electron beam under cyclotron resonance conditions
    Physical Review Letters, 2010
    Co-Authors: N S Ginzburg, I.v. Zotova, A.s. Sergeev
    Abstract:

    Based on analogy to the well-known process of the self-induced transparency of an optical Pulse propagating through a passive two-level medium we describe similar effects for a microwave Pulse interacting with a cold plasma or rectilinear electron beam under cyclotron resonance condition. It is shown that with increasing amplitude and duration of an incident Pulse the linear cyclotron absorption is replaced by the self-induced transparency when the Pulse propagates without damping. In fact, the initial Pulse decomposes to one or several solitons with amplitude and duration defined by its velocity. In a certain parameter range, the single soliton formation is accompanied by significant compression of the initial Electromagnetic Pulse. We suggest using the effect of self-compression for producing multigigawatt picosecond microwave Pulses.

  • Amplification of a short Electromagnetic Pulse propagating through an electron beam
    13th International Crimean Conference Microwave and Telecommunication Technology 2003. CriMiCo 2003., 2002
    Co-Authors: Naum S. Ginzburg, I.v. Zotova, A.s. Sergeev
    Abstract:

    The amplification of a short Electromagnetic Pulse propagating through a stationary electron Pulse with group velocity different from that of the translational electron velocity has been researched. It has been shown that due to the constant feeding of the backfront of an Electromagnetic Pulse by nonmodulated electrons the peak Pulse amplitude may substantially exceed levels corresponding to the saturation level for the amplification of CW signals.

Ali Abur - One of the best experts on this subject based on the ideXlab platform.

  • field test and theoretical analysis of Electromagnetic Pulse propagation velocity on crossbonded cable systems
    IEEE Transactions on Power Delivery, 2014
    Co-Authors: Christian F. Jensen, Unnur Stella Gudmundsdottir, Ali Abur
    Abstract:

    In this paper, the Electromagnetic Pulse propagation velocity on a three-phase cable system, consisting of three single core (SC) cables in flat formation with an earth continuity conductor is under study. The propagation velocity is an important parameter for most travelling wave off- and online fault location methods and needs to be exactly known for optimal performance of these algorithm types. Field measurements are carried out on a 6.9 km and a 31.4 km 245 kV crossbonded cable system, and the results are analysed using the modal decomposition theory. Several ways for determining the propagation velocities for the coaxial and intersheath modes velocities are presented using both single- and synchronized double ended measuring methods. The accuracy of the different methods is evaluated and the results are compared to simulations and theoretical calculated values. Good agreement is found between the different proposed methods and theoretical values. The deviations are explained and a sensitivity analysis is carried out on the most important parameters.

  • Field test and theoretical analysis of Electromagnetic Pulse propagation velocity on crossbonded cable systems
    IEEE Transactions on Power Delivery, 2014
    Co-Authors: Christian F. Jensen, Claus L. Bak, Unnur Stella Gudmundsdottir, Ali Abur
    Abstract:

    In this paper, the Electromagnetic Pulse propagation velocity on a three-phase cable system, consisting of three single core (SC) cables in flat formation with an earth continuity con- ductor is under study. The propagation velocity is an important parameter for most travelling wave off- and online fault location methods and needs to be exactly known for optimal performance of these algorithm types. Field measurements are carried out on a 6.9 kmand a 31.4 km245 kV crossbonded cable system, and the re- sults are analysed using the modal decomposition theory. Several ways for determining the propagation velocities for the coaxial and intersheath modes velocities are presented using both single- and synchronized double ended measuring methods. The accuracy of the different methods is evaluated and the results are compared to simulations and theoretical calculated values. Good agreement is found between the different proposed methods and theoretical values. The deviations are explained and a sensitivity analysis is carried out on the most important parameters. Index

He Li - One of the best experts on this subject based on the ideXlab platform.

  • The simulation of Electromagnetic Pulse coupling with computer box
    Proceedings. ICCEA 2004. 2004 3rd International Conference on Computational Electromagnetics and Its Applications 2004., 2004
    Co-Authors: Chen Xiuqiao, Hu Yihua, Zhang Jianhua, Huang Yourui, He Li
    Abstract:

    The high power Electromagnetic Pulse couples into a computer box through small apertures and slots, which can interfere with and destroy the computer. The coupling process of Electromagnetic Pulse with computer box is simulated by using the finite-difference time-domain (FDTD) method. Analyzing the change of Electromagnetic field and energy with time, the coupling characteristic of Electromagnetic Pulse is obtained. Besides, the simulation of Electromagnetic Pulse coupling with the computer box is important for the study on Electromagnetic compatibility, interference and protection of computer systems.

  • Simulation of Electromagnetic Pulse Coupling with Computer Box
    2004
    Co-Authors: He Li
    Abstract:

    High power Electromagnetic Pulse couples into computer box through small apertures and slots, which can interfere with or destroy computer. The coupling process of Electromagnetic Pulse with computer box is simulated by using the finite-difference time-domain (FDTD) method. By analyzing the Electromagnetic field and energy changing with time, the coupling characteristic of Electromagnetic Pulse is achieved. Besides, the simulation of Electromagnetic Pulse coupling with computer box is important for the research of Electromagnetic compatibility, interference and defense of computer system.

W.a. Radasky - One of the best experts on this subject based on the ideXlab platform.

  • progress in high altitude Electromagnetic Pulse hemp standardization
    IEEE Transactions on Electromagnetic Compatibility, 2013
    Co-Authors: R Hoad, W.a. Radasky
    Abstract:

    Since the publication of the last IEEE Transactions on Electromagnetic Compatibility special issue on nuclear Electromagnetic Pulse in 1978, significant progress has been made in the development of high-altitude Electromagnetic Pulse (HEMP) standards. The standards cover HEMP environment definition, protection requirements, and test methods. In particular, civilian standards have been developed in recent times as it is recognized that the impact of HEMP disturbances is not just a concern for the military but also a concern for the largely civilian critical national infrastructure. This paper provides a summary of the HEMP standards that are presently available in the military and civilian domains.

  • Generation of High-altitude Electromagnetic Pulse (HEMP)
    2008 IEEE International Symposium on Electromagnetic Compatibility, 2008
    Co-Authors: W.a. Radasky
    Abstract:

    In this presentation, the generation of high-altitude Electromagnetic Pulse (HEMP), its historical evidence and threat, and the different phases of HEMP (early-time, intermediate and late-time) are discussed.