International Journal of Antennas and Propagation / 2018 / Article / Fig 4

Research Article

Finite-Difference Time Domain Techniques Applied to Electromagnetic Wave Interactions with Inhomogeneous Plasma Structures

Figure 4

Equivalence principle.
(a) Fictitious boundary for the problem at hand. Fields inside and outside the boundary are continuous across it
(b) Equivalent problem with fields inside the fictitious boundary set to zero and material properties set to that of free space