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.

A simple technique for solving E -field integral equations for conducting bodies at internal resonances

Abstract: A simple but effective method is presented to analyze electromagnetic radiation and scattering from condueting bodies at frequencies corresponding to internal resonances of a cavity of the same shape. The advantage of this technique is that it requires only the E -field integral equation and hot both E -field and H -field as required by the combined fields formulation. It is shown theoretically that this method produces a solution with minimum norm and converges monotonically as the order of the approximation is increased. The minimum norm solution for the current density given by the E -field integral equation is not the correct current density as there is a portion of the resonant current that exists on the body. However, the minimum norm solution indeed provides the true scattering fields. This technique may also be utilized for obtaining a minimum norm solution for nearly singular and singular matrix equations. Examples are presented to illustrate the application of this technique.

3D FDTD method for arbitrary anisotropic materials

Abstract: A generalized 3D finite-difference time-domain (FDTD) method for the modeling of electromagnetic wave interaction with a full anisotropic media is presented The proposed formulation is applied to three configurations: a microstrip patch antenna with anisotropic substrates, weakly magnetic ferrite absorbers with punctured holes, and a waveguide loaded with heterogeneous anisotropic magnetic materials Computed results show that anisotropic material can have great effects on system properties and can add another degree of design freedom © 2006 Wiley Periodicals, Inc Microwave Opt Technol Lett 48: 2083–2090, 2006; Published online in Wiley InterScience (wwwintersciencewileycom) DOI 101002/mop21871

A Wave-Chaotic Approach To Predicting And Measuring Electromagnetic Field Quantities In Complicated Enclosures

Abstract: Title of Document: A WAVE-CHAOTIC APPROACH TO PREDICTING AND MEASURING ELECTROMAGNETIC FIELD QUANTITIES IN COMPLICATED ENCLOSURES Sameer D. Hemmady, Doctor of Philosophy, 2006 Directed By: Dr. Steven M. Anlage ProfessorDept. of Physics Affiliate FacultyDept. of Electrical Engineering The coupling of short-wavelength electromagnetic waves into large complicated enclosures is of great interest in the field of electromagnetic compatibility engineering. The intent is to protect sensitive electronic devices housed within these enclosures from the detrimental effects of high-intensity external electromagnetic radiation penetrating into the enclosure (which acts as a resonant cavity) through various coupling channels (or ports). The Random Coupling Model introduced by Zheng, Antonsen and Ott is a stochastic model where the mechanism of the coupling process is quantified by the non-statistical “radiation impedance” of the coupling-port, and the field variations within the cavity are conjectured to be explained in a statistical sense through Random Matrix Theoryby assuming that the waves possess chaotic ray-dynamics within the cavity. The Random Coupling Model in conjunction with Random Matrix Theory thus makes explicit predictions for the statistical aspect (Probability Density Functions-PDFs) of the impedance, admittance and scattering fluctuations of waves within such wave-chaotic cavities. More importantly, these fluctuations are expected to be universal in that their statistical description depends only upon the value of a single dimensionless cavity loss-parameter. This universality in the impedance, admittance and scattering properties is not restricted to electromagnetic systems, but is equally applicable to analogous quantities in quantum-mechanical or acoustic systems, which also comprise of short-wavelength waves confined within complicated-shaped potential wells or acoustic-resonators. In this dissertation, I will experimentally show the validity of the “radiation impedance” to accurately quantify the port-coupling characteristics. I will experimentally prove the existence of these universal fluctuations in the impedance, admittance and scattering properties of quasi-two-dimensional and three-dimensional wave-chaotic systems driven by one-port or two-ports, and validate that their statistical nature is described through Random Matrix Theory. Finally, I will utilize the Random Coupling Model to formulate a prediction-algorithm to determine the shape and scales of induced voltages PDFs at specific points within complicated enclosures, such as computer boxes, when irradiated by high-intensity, shortwavelength electromagnetic energy. The insight gained from the experimental validation of the Random Coupling Model allows one to conceive of certain designguidelines for cavity-enclosures that are more resistant to attack from an external short-wavelength electromagnetic source. A WAVE-CHAOTIC APPROACH TO PREDICTING AND MEASURING ELECTROMAGNETIC FIELD QUANTITIES IN COMPLICATED ENCLOSURES

Electrodynamics of visible-light interactions with the vertebrate retinal rod.

Abstract: We report the initial investigation of the electrodynamics of visible-light interaction with the outer segment of the vertebrate retinal rod based on detailed, first-principles computational electromagnetics modeling. The computational method employs a direct time integration of Maxwell’s equations in a two-dimensional space grid for both transverse-magnetic and transverse-electric vector-field modes. Detailed maps of the optical standing wave within the retinal rod are given for three illumination wavelengths: 714, 505, and 475 nm. The standing-wave data are Fourier analyzed to obtain spatial frequency spectra. Except for isolated peaks, the spatial frequency spectra are essentially independent of the illumination wavelength.