Higher order absorbing boundary conditions are introduced and implemented into a finite-difference time-domain (FDTD) computer code. Reflections caused by the absorbing boundary conditions are examined. For the case of a point source radiating in a finite computational domain, it is shown that the error decreases as the order of approximation of the absorbing boundary condition increases. Fifth-order approximation reduces the normalized reflections to less than 0.2% whereas the widely used second-order approximation produces about 3% reflections. A method for easy implementation of any order approximation is also presented.
ASJC Scopus subject areas
- Electrical and Electronic Engineering