“…The method utilizing the exact absorbing conditions for the artificial boundaries that truncate an unbounded domain of computation [1-9, 20, 21] is outnumbered by the classical approximate approaches. However, testing numerical experiments as well as a series of physical and applied results obtained with the help of this method (see, e.g., [3,5,8,[21][22][23][24][25][26][27][28][29][30]) shows its evident potential, especially, for obtaining reliable numerical data on space-time and space-frequency electromagnetic field transformations in open waveguide, periodic, and compact resonators.…”