Computational electromagnetics

About: Computational electromagnetics is a research topic. Over the lifetime, 6412 publications have been published within this topic receiving 113727 citations. The topic is also known as: Electromagnetic field analysis.

On the equations governing the electromagnetic perturbations of the Kerr black hole

Abstract: The equations governing the electromagnetic perturbations around a rotating black hole are examined and found to yield a simple, one dimen­sional wave equation with a short range and purely real potential.

Efficient Cohomology Computation for Electromagnetic Modeling

Abstract: The systematic potential design is of high importance in computational electromagnetics. For example, it is well known that when the efficient eddycurrent formulations based on a magnetic scalar potential are employed in problems which involve conductive regions with holes, the so-called thick cuts are needed to make the boundary value problem well defined. Therefore, a considerable effort has been invested over the past twenty-five years to develop fast and general algorithms to compute thick cuts automatically. Nevertheless, none of the approaches proposed in literature meet all the requirements of being automatic, computationally efficient and general. In this paper, an automatic, computationally efficient and provably general algorithm is presented. It is based on a rigorous algorithm to compute a cohomology basis of the insulating region with state-of-art reductions techniques—the acyclic sub-complex technique, among others—expressly designed for cohomology computations over simplicial complexes. Its effectiveness is demonstrated by presenting a number of practical benchmarks. The automatic nature of the proposed approach together with its low computational time enable the routinely use of cohomology computations in computational electromagnetics.

Automatic electromagnetic solvers based on mode-matching, transverse resonance, and S-matrix techniques

Abstract: The main goal of the paper is to present a new generalized mode-matching (GMM) approach to both mode bases and S-matrices calculation of complicated waveguide circuits. Development of the GMM procedures makes it possible to realize totally automatic algorithms for a wide set of configurations avoiding a specialized analytical treatment of each new boundary-value problem. Moreover, the background for linking up the interface tools of a circuit geometry specification and editing is provided by the GMM approach together with the special algorithms for recognizing the object configurations and for data preparation. The class of objects that can be calculated by the suggested approach includes any WG circuits with metal boundaries specified in the Cartesian coordinate system or with the smooth boundaries that may be replaced by a staircase surface. The corresponding electromagnetic solvers are closer to the software based on the mesh methods in generality, in the same time saving the high accuracy and computation speed typical for highly specialized mode-matching procedures.

Far-field contribution of evanescent modes to the electromagnetic Green tensor

Abstract: Understanding the behavior of the evanescent part of the electromagnetic field has important implications in many branches of modern physics, such as near-field optics. Motivated by recent disagreement in the literature, we derive an expression for the far-field asymptotic behavior of the free-space electromagnetic Green tensor that is due to the evanescent modes.

GA/FDTD technique for the design and optimisation of periodic metamaterials

Abstract: An efficient and powerful full-wave electromagnetic technique is presented to characterise and design periodic metamaterial structures. First, the spectral finite-difference time-domain (FDTD) method with periodic boundary conditions and uniaxial perfect matched layer is employed to predict the performance of a mushroom-like artificial magnetic conductor (AMC) surface and further extended to characterise a negative-refractive-index material consisting of lumped and distributed transmission-line elements. Then, a new computational technique is developed to design and optimise periodic metamaterial structures by integrating the spectral FDTD method with a genetic algorithm (GA), namely the micro-genetic algorithm. This computational technique is successfully applied to design and optimise single-band and dual-band AMC structures consisting of a frequency-selective surface and a ground plane. It is demonstrated that the GA/FDTD technique is a very effective approach for the design and optimisation of periodic metamaterial structures consisting of dielectrics and conductors of arbitrary configurations.