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Electrical and Computer Engineering

Selected Works

2016

Permittivity

Articles 1 - 2 of 2

Full-Text Articles in Engineering

Fdtd Modeling Of Isotropic Dispersive Magnetic Materials, Jing Wu, Marina Koledintseva, James L. Drewniak, David Pommerenke Jul 2016

Fdtd Modeling Of Isotropic Dispersive Magnetic Materials, Jing Wu, Marina Koledintseva, James L. Drewniak, David Pommerenke

James K. Wu, M.D.

Numerical analysis using the finite-difference time-domain (FDTD) algorithm with a piecewise linear recursive convolution (PLRC) procedure for linear isotropic dispersive magnetic materials is presented. The frequency dependence of susceptibility used for this algorithm is represented in Debye, narrowband Lorentzian, and wideband Lorentzian forms, depending on the ratio of the resonance frequency and the resonance line width. Some numerical examples along with measurements are provided.


Representation Of Permittivity For Multiphase Dielectric Mixtures In Fdtd Modeling, Marina Koledintseva, J. Wu, H. Zhang, James L. Drewniak, Konstantin Rozanov Jul 2016

Representation Of Permittivity For Multiphase Dielectric Mixtures In Fdtd Modeling, Marina Koledintseva, J. Wu, H. Zhang, James L. Drewniak, Konstantin Rozanov

James K. Wu, M.D.

A simple method of approximating frequency characteristics of composites in a form convenient for time-domain numerical modeling is proposed. The frequency characteristics can be obtained from experiment or calculations based on the Maxwell Garnett mixing formalism. The resultant frequency characteristic might be of a complex shape corresponding to a combination of a number of absorption peaks. The approximation is made by a series of Debye-like terms using a genetic algorithm (GA). This leads to the necessity of taking a number of terms in the approximating series. Every term corresponds to its pole, i.e., the frequency where the maximum loss occurs. …