A 3-D adaptive integral method (AIM) for layered media

This article extends the adaptive integral method (AIM) to the analysis of scattering from 3-D PEC objects fully embedded inside a single layer of a planar layered medium. Just like for the classical AIM for free-space backgrounds, first, the pertinent integral equations are discretized via the MOM; second, the impedance matrix entries are separated into nearand far-zone terms using an auxiliary regular grid; and third, the impedance matrix entries are approximated using sources and observers on the regular grid while the near-zone terms are pre-corrected using the original MOM matrix entries.