An FFT-Accelerated FDTD Scheme With Exact Absorbing Conditions for Characterizing Axially Symmetric Resonant Structures

Abstract

Abstract-An accurate and efficient finite-difference time-domain (FDTD) method for characterizing transient waves interactions on axially symmetric structures is presented. The method achieves its accuracy and efficiency by employing localized and/or fast Fourier transform (FFT) accelerated exact absorbing conditions (EACs). The paper details the derivation of the EACs, discusses their implementation and discretization in an FDTD method, and proposes utilization of a blocked-FFT based algorithm for accelerating the computation of temporal convolutions present in nonlocal EACs. The proposed method allows transient analyses to be carried for long time intervals without any loss of accuracy and provides reliable numerical data pertinent to physical processes under resonant conditions. This renders the method highly useful in characterization of high-Q microwave radiators and energy compressors. Numerical results that demonstrate the accuracy and efficiency of the method are presented.

A Simple Local Approximation FDTD Model of Short Apertures With a Finite Thickness

“…The finite-difference time-domain (FDTD) method has been widely applied in solving many types of electromagnetic scattering problems [1][2][3][4][5][6][7][8]. It possesses the advantages of simple and accurate implementation for relatively complex problems.…”

Performance of FDTD Method Cpu Implementations for Simulation of Electromagnetic Processes

“…• Different FDTD method implementations are considered, that may or may not simulate such material properties as dispersion, nonlinearity, anisotropy, etc., and use various numerical schemes [5,6,[19][20][21][22][23].…”

Analysis of Transient Electromagnetic Scattering Using Time Domain Fast Dipole Method

“…When analyzing the scattering from perfect electric conductor (PEC), the TDIE methods require a discretization of the scatterer surface and do not call for absorbing boundary conditions in the finite difference time domain [7,8]. However, with the electrical size of the scatterer increasing, the memory requirement and the computational complexity become very expensive.…”