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Bad Munster am Stein-Ebernburg, Germany

Tkachenko S.,Otto Von Guericke University of Magdeburg | Nitsch J.,Otto Von Guericke University of Magdeburg | Rambousky R.,Bundeswehr Research Institute for Protective Technologies
Ultra-Wideband, Short-Pulse Electromagnetics 10 | Year: 2014

In this chapter, the analysis of transmission lines inside rectangular resonators is extended from one conductor with two sources/loads at the ends to many loads along the conductor and to the interaction between two conductors. To do this, the many loads are described as passive small (δ-) sources, whose corresponding electrical fields superpose with fields from other sources. The currents in the individual loads are found by imposing the boundary condition for the total electrical field on the surface of the conductor and applying a Fourier series expansion for the current. The calculation of the interaction of two lines in the resonator is based on the known description for one conductor and the two-dimensional Green's function, which occurs in the analytical expressions for the currents. This Green's function is used for both conductors separately. Then, with the aid of the superposition principle, the individual currents for the lines are derived. These computational procedures are illustrated by two examples. © Springer Science+Business Media New York 2014. Source


Nitsch J.B.,Otto Von Guericke University of Magdeburg | Tkachenko S.V.,Otto Von Guericke University of Magdeburg | Potthast S.,Bundeswehr Research Institute for Protective Technologies
IEEE Transactions on Electromagnetic Compatibility | Year: 2012

In this paper, analytical solutions of response functions for rectangular resonators are investigated in time domain. Emphasis is placed on the study of electromagnetic field coupling to a 3-D cavity through a small circular aperture. The time-dependent parts of the resulting modal Greens functions exhibit typical behavior that is inherent in all resonating/oscillating linear physical systems: namely, they fulfill oscillating ordinary differential equations at any point of the considered resonator. Their solutions contain transient and steady-state parts. The transient parts of the response functions will become important for electromagnetic compatibility tests in particular of modern digital high-speed electronics. © 1964-2012 IEEE. Source


Tkachenko S.V.,Otto Von Guericke University of Magdeburg | Rambousky R.,Bundeswehr Research Institute for Protective Technologies | Nitsch J.B.,Otto Von Guericke University of Magdeburg
IEEE Transactions on Electromagnetic Compatibility | Year: 2013

This paper calculates the current in a conductor inside a cavity, which is induced by lumped and distributed sources. The current is obtained both analytically (Green's function method) and numerically (multilevel fast multipole method). A long parallel wire is chosen that connects two opposite walls of a rectangular resonator. Since the conductor preserves the translational symmetry of the resonator in one principal direction, the current and the total exciting electrical field can be derived from spatial Fourier series formulations. The obtained results clearly show the influence of the walls on the induced current. Resonance peaks of the resonator, which do not arise in normal electromagnetic compatibility laboratory tests, occurred in the current spectra. The numerical results agree very well with the analytical ones; however, the results are obtained much faster using the analytical formulae (by a factor of 1000). © 1964-2012 IEEE. Source


Rambousky R.,Bundeswehr Research Institute for Protective Technologies | Nitsch J.B.,Otto Von Guericke University of Magdeburg | Garbe H.,Leibniz University of Hanover
IEEE Transactions on Electromagnetic Compatibility | Year: 2013

Open TEM-waveguides are often realized by multiwire structures instead of conducting planes. Especially for large-scale nuclear electromagnetic pulse (NEMP) simulators the wire structure is common. In this paper, a generic open TEM-waveguide structure is analyzed using the transmission-line super theory (TLST). The concept of the numerical implementation is thoroughly described independent of a particular programming language. The TLST comprises full Maxwell's equations assuring that higher order modes and radiation effects are included. Currents along the lines and the total radiated power outside the simulator are calculated. Inside the simulator the magnetic field is estimated in the working volume, and the result is verified by experiment. The presented theory is applicable not only to the described simulator structure but also to a variety of wire-based problems in electromagnetic compatibility. © 2013 IEEE. Source


Rambousky R.,Bundeswehr Research Institute for Protective Technologies | Tkachenko S.,Otto Von Guericke University of Magdeburg | Nitsch J.,Otto Von Guericke University of Magdeburg
IEEE International Symposium on Electromagnetic Compatibility | Year: 2013

In this paper electric field coupling to a transmission line located symmetrically inside a rectangular cavity is investigated. The applied distributed fields have different origin: Firstly, one field is generated inside the cavity by a small electrical antenna, and secondly, the other field stems from a plane wave which couples through a circular hole into the cavity. In every case the respective field contributes to the induced current on the line. The line is treated in the thin-wire approximation and the induced currents are calculated at the terminations of the wire. Two methods are applied to obtain the currents: an analytical method and a numerical package using a MLFMM-procedure. The comparison of both results shows good agreement. The advantage of the analytical calculation is the much shorter. © 2013 IEEE. Source

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