A self-consistent formalism of absorbing boundary condition for modeling unbounded electromagnetic structures

A simple approach is proposed to construct a class of absorbing boundary conditions which is suitable for modeling completely or partially unbounded electromagnetic structures under finite-element and/or finite-difference frameworks. These self-consistent absorbing boundary conditions are derived and obtained by applying the method of lines with various coordinate systems, which are formulated in terms of analytical matrix equations. Potential application of the absorbing boundary conditions may be found in frequency domain as well as in rime domain with interesting features related to mesh truncation, modeling of radiation, scattering and propagation problems. Demonstrative result is presented for a simple one-dimensional geometry.