R.Yu. Borodulin1, N.O. Lukianov2

1,2 Military Academy of Communications. Marshal of the Soviet Union named after S.M. Budyonny
(St. Petersburg, Russia)

The finite difference time domain method (FDTD) is one of the most popular methods for solving problems in electrodynamics [1]. In computer simulation of electrodynamic problems by the FDTD method, Moore's absorbing boundary conditions (of the 1st and 2nd order of accuracy) and Beranger [2-6] are used. The Moore boundary conditions used do not require additional manipulations with Maxwell's equations, but their effective operation requires fine tuning of the grid parameters, namely: the layer thickness and the distance from the radiation source to the boundary of the computational domain. To automate the procedure for setting the Moore boundary conditions, it is advisable to conduct a current analysis of the instantaneous values of the reflected wave amplitude, for example, at the lowest frequency of the range before the inverse Fourier transform, after which the complex field amplitudes will be obtained. This will make it possible to estimate in advance the amplitude of the resulting standing wave and minimize the consequences of its influence on the calculated fields, without waiting for the end time of the algorithm. The performance of Moore boundary conditions can be improved by using a combination of 1st and 2nd order layers.

The article presents a technique for evaluating the efficiency of Moore boundary conditions of the 1st and 2nd order of accuracy, as well as their mixed layers. To solve various electrodynamic problems with high accuracy by the FDTD method, it makes sense to apply various boundary conditions, however, the choice of their parameters is a compromise between the required computing resources and the calculation accuracy, which can be found.

Borodulin R.Yu., Lukianov N.O. Methodology for evaluating work efficiency absorbing Moore boundary conditions when solving problems of electrodynamics finite difference time domain method. Radiotekhnika. 2022. V. 86. № 5. P. 104−110. DOI: https://doi.org/10.18127/j00338486-202205-13 (In Russian)

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