Efficient Electromagnetic Scattering Simulation of Electrically Extra-Large Problems Using Phase Information and Adaptive Mesh Automation

In this article, an efficient simulation method is proposed to analyze extra-large electromagnetic scattering problems. With the incorporation of the traveling wave phase, the phase-extracted basis functions (PEBFs) can be defined on very large mesh elements, which effectively reduce the number of unknowns by two orders of magnitude, making it possible to simulate extra-large problems. Although the PEBFs were applied successfully in analyzing smooth and convex objects, they cannot accurately model the induced surface currents when geometrical singularities or strong mutual couplings are present. In such cases, the mesh elements must be small enough to describe the complicated amplitude variations accurately. One way to tackle this issue is to use a locally refined mesh. In this article, a set of rules is proposed, based on the geometrical and physical features of the problem, to identify elements that need to be locally refined. The mesh refinement is performed automatically based on the proposed rules, eliminating the need for human intervention. The discontinuous Galerkin integral equation (DGIE) method has been employed to handle the nonconformal mesh generated from the automatic mesh refinement. Numerical examples from smooth and nonsmooth objects are presented to demonstrate the performance of the method.