Scattering from planar structures containing small features using the adaptive integral method (AIM)

Fast integral equation algorithms such as the adaptive integral method (AIM) have been demonstrated to reduce memory and execution time associated with moment-method solutions for arbitrarily shaped three-dimensional (3-D) geometries. In this paper, we examine the efficiency of AIM in modeling planar structures that contain small and intricate details as is the case with spirals and slot antennas. Such geometries require high tessellation due to the inclusion of very small features resulting in a large number of unknowns. AIM with its capability to translate the original grid to an equivalent sparser uniform grid is uniquely suited for the analysis of such geometries. In the latter part of the paper, we demonstrate the application of AIM in connection with a finite-element boundary-integral formulation for cavity-backed antennas.