Subcell Modeling of Frequency-Dependent Thin Layers in the FDTD Method

Abstract

Index Terms-Thin layer, subcell technique, Debye media, finite difference, FDTD, bioelectromagnetism.Abstract-A subcell modelling technique for frequency dependent thin layers in finite-difference time-domain (FDTD) method is introduced. The proposed method is based on the application of the integral form of the Maxwell-Ampere equation and the solution of a set of auxiliary equations to advance the field components. It has the ability to handle one or several frequency dependent thin layers embedded in a frequency dependent medium without solving high-order differential equations. To validate our proposed method, we compare the obtained results with analytical solutions and with numerical references in both time domain and frequency domain.

Theoretical Comparison of Methods for Modeling Thin Dielectric or Conducting Sheets in the FDTD Grid

“…Further investigations will compare methods [1] and [3] in realistic applications and with canonical objects composed with several sheets of finite sizes. The comparisons will also be extended to the dispersive sheet method reported in [12].…”

“…Solving the equations for reflection R and transmission T yields In the case a= 1, b=1+(s-1) d/x, = 1, and = 0, which corresponds to technique [3], the reflection (12) becomes The bracket in (14) vanishes for cos 2…”

Numerical and Experimental Time-Domain Characterization of Terahertz Conducting Polymers

“…where t ij = 2n i /(n i + n j ) and r ij = (n j − n i )/(n i + n j ) are the Fresnel transmittance and reflectance coefficients, respectively, at the interface between media i and j and n i,j their complex refractive indices. The rest of the parameters in (17) are t 123 = t 12 t 23 P 2 /(1 − r 21 r 23 P 2 2 ), r 123 = (r 12 + r 23 P 2 2 )/(1+r 12 r 23 P 2 2 ), where…”

“…The investigation is backed by a subcell FDTD formulation that tackles both the dispersive nature and arbitrary TCF thicknesses, being more robust than its conventional uniform-grid counterpart. Although subcell FDTD techniques for thin films are known [16], [17], the proposed algorithm enables the modelling of DS-TCF placed between a Debye medium and a plain dielectric. Hence, it addresses the relevant paradigm for the study of THz-TCF, without being restricted to the specific choice of materials and frequencies.…”

A Statistical Parsimony Method for Uncertainty Quantification of FDTD Computation Based on the PCA and Ridge Regression

“…This paper deals with the numerical simulation of the propagation of electromagnetic waves in the human body. In the FDTD calculations, the one-pole Debye model [4] is utilised to describe the frequency-dependent behaviour of human tissues whose frequency response varies from person to person. Such variation is termed as uncertainty.…”