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Item type:Publication, Access status: without files , Modeling challenging EMC problems(IEEE, 2017-11-02); ; ; ; A variety of numerical techniques is used in electromagnetic compatibility (EMC) for the numerical analysis of practical problems. The most important are the finite-difference timedomain technique, the finite-element method, the transmissionline-matrix method and the method of moments. All approaches have their strengths and weaknesses and cannot be applied to all kinds of problems with the same degree of efficiency, measured in memory consumption and computation time necessary. In this paper, it is shown that the method of moments (MoM) can be applied to a variety of scenarios, each of which would form a challenging problem to all of the mentioned numerical techniques. It is shown that a customization of the MoM to the specific problems at hand can be accomplished. All examples shown have been computed using the academic code CONCEPT-II developed at Hamburg University of Technology (TUHH).Publicationtype: Journal Article148 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: without files , Numerical Shielding Analysis of Anisotropic Multilayer Materials by the Method of Moments(IEEE, 2016-09-05); ; ; ; In this contribution, an efficient method is developed to calculate the shielding effectiveness of anisotropic conducting multilayer materials by the method of moments. An analytical solution is used to approximate the wave propagation inside the multilayer material. This solution is coupled with a method of moments implementation, allowing to numerically calculate the electromagnetic fields in exterior and interior regions of a shield. Obtained results are compared to those of alternative numerical techniques and form the basis to validate the modeling of anisotropic multilayer materials by a homogeneous material of equivalent conductivity.Publicationtype: Journal Article71 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: without files , HIRF transfer function observations: Notes on results versus requirements and certification approach(2015-04-01); ; ; ; HIRF transfer functions results are rarely available to the public. Generally, the data provided in applicable guidance material are used for estimation of internal HIRF environment in an air vehicle. An exemplary set of HIRF transfer functions for a small aircraft is presented here. Results for the aircraft (10.4-m wingspan and 8.3 m of length) are compared with regard to state of the art approaches applied for aircraft HIRF certification campaigns. This is done in appropriate frequency ranges and by the use of applicable test methods with regard to requirements in place. For all major types of contemporary test methods, results are generated by measurement and numerical computer modeling. Principles of outcomes are discussed and compared to current practice in place. This concerns the shapes of the transfer functions on one hand and the order of magnitudes of obtained levels on the other hand. The obtained results show significant deviations from generic transfer functions currently applied in aircraft industry. The coupling to the interior of the aircraft observed here was higher than indicated by the applicable generic transfer functions. Numerical computer modeling is used here to verify the obtained outcomes by principle.Publicationtype: Journal Article46 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: without files , 56 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: without files , A method for the calculation of electromagnetic fields in the presence of thin anisotropic conductive layers using the method of momentsIn this paper a method is presented which allows to calculate the electromagnetic field in the presence of a material that consists of several thin layers with anisotropic conductivity. The proposed method combines an analytic solution for the field inside the layer with the method of moments. By comparison to other field solvers, it is demonstrated that the presented method yields correct results. © 2013 EMC Europe Foundation.Publicationtype: Conference Paper26 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: without files , Efficient compression of far field matrices in multipole algorithms based on spherical harmonics and radiating modesThis paper proposes a compression of far field matrices in the fast multipole method and its multilevel extension for electromagnetic problems. The compression is based on a spherical harmonic representation of radiation patterns in conjunction with a radiating mode expression of the surface current. The method is applied to study near field effects and the far field of an antenna placed on a ship surface. Furthermore, the electromagnetic scattering of an electrically large plate is investigated. It is demonstrated, that the proposed technique leads to a significant memory saving, making multipole algorithms even more efficient without compromising the accuracy.Publicationtype: Journal Article99 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: without files , Investigation of field coupling into a carbon fiber aircraft fuselage with the method of momentsIn this paper the field coupling into a fuselage model consisting of carbon fiber composite with apertures is analyzed by means of the Method of Moments. A set of two boundary integral equations, involving two current layers, is applied for accurate treatment of aperture coupling. The considered anisotropic shell is investigated by two approaches, where the modeling is accomplished using boundary impedances and a multilayer technique, respectively. The applicability of these techniques is studied and validated by reference computations on generic test objects. It turns out that the results gained by the proposed techniques are in very good agreement with results of the finite element method.Publicationtype: Conference Paper13 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: without files , Numerical and experimental investigations on a metallic fuselage model with aperturesIn this paper the coupling of fields into the interior of a cylindrical metallic cavity with apertures is investigated, both numerically and experimentally. The question arises whether and to what extent the internal field distribution can be determined in a method of moments (MoM) based simulation. It is known from literature that the classical electric field integral equation (EFIE) approach is not able to provide a zero field inside a completely closed body. Hence the in-coupled fields may become distorted by the superposition of spurious solutions also in the presence of small apertures. It will be demonstrated that an integral equation approach which is based on two different electric current layers provides solutions which are in a good agreement with measured results. The obtained results are interpreted with respect to EMC requirements in aircraft. © 2011 EMC Europe.Publicationtype: Conference Paper17 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: without files , Frame dislocation of body middle rings in endovascular stent tube grafts(Elsevier, 1999)5