Accurate and Efficient Finite-Difference Time-Domain Simulation Compared With CCPR Model for Complex Dispersive Media

Abstract

Recently, it has received a great deal of attention to analyze the electromagnetic wave problems in dispersive media by using the finite-difference time-domain (FDTD) method. Accordingly, it is of great importance to employ a proper dispersion model which can fit the frequency-dependent permittivity of a medium considered. The reported dispersion models include Debye, Drude, Lorentz, modified Lorentz, quadratic complex rational function, complex-conjugate pole-residue (CCPR) models. The CCPR dispersion model has advantage over other dispersion models in the fact that accurate CCPR dispersion parameters can be simply extracted by using the powerful and robust vector fitting tool which has been widely used in the circuit theory. However, the arithmetic operation of CCPR-based FDTD implementation is involved with complex-valued numbers and thus its numerical computation is not efficient. In this work, we propose an accurate and efficient FDTD simulation for complex dispersive media. In specific, an accurate CCPR dispersion model is simply obtained using the vector fitting tool and then the CCPR dispersion model is converted to the modified Lorentz dispersion model which leads to the arithmetic operation of only realvalued numbers in its FDTD implementation. Numerical examples are used to illustrate the accuracy and efficiency of our dispersive FDTD simulation. INDEX TERMS Dispersion model, dispersive media, finite-difference time-domain (FDTD) method, human tissue, plasmonics.

Radio Optical Network Simulation Tool (RONST)

“…The finite-difference time-domain (FDTD) is a numerical technique that has proved its efficiency in solving PDEs and characterizing many problems [28][29][30][31]. However, in the case of increasing the dimensions or the complexity of the problem domain, the solution will need more computational resources in terms of time and memory.…”

Numerical Accuracy of Finite-Difference Time-Domain Formulations for Magnetized Plasma

“…Note that the z component of tensor permittivity is reciprocal because the external static magnetic field does not affect the wave behavior in that direction [15].…”

“…The ETD method avoids the time-consuming recursive convolution based on an efficient first-order approximation. Simple arithmetic implementation is involved in the ADE method, which can also be straightforwardly extended to nonlinear dispersive media, unlike other methods [15,16]. There are two particular implementations in the ADE method for EM analysis of magnetized plasma.…”

Finite-difference wave-propagation models for dispersive media: impact of space-time discretization

“…The suitability of a computational scheme for the simulation of electromagnetic phenomena depends on various factors, one of which is the consistent modeling of the involved materials. Regarding high-frequency electromagnetic problems, finite-difference time-domain (FDTD) methodologies (Taflove and Hagness, 2005) are capable of incorporating a wide variety of material properties, such as anisotropy (Werner and Cary, 2007), dispersion (Young, 1995; Weedon and Rappaport, 1997; Teixeira et al , 1998; Ramadan, 2017; Choi et al , 2019), chirality (Bouzianas et al , 2009) and nonlinearity (Joseph and Taflove, 1997). Nevertheless, the approximate nature of such techniques is an issue that should be always taken into consideration, if their applicability range and potential are to be assessed in a reliable fashion.…”