Applying LF-MLFMA to solve complex PEC structures

In this paper, the wire–surface basis is reviewed. The original hard wire–surface basis is divided into independent small wire–surface bases. This new wire–surface basis consists of only one wire segment and one triangular patch. It simulates more accurately the current distribution near the junction, and is easier to form the wire–surface global loop basis for low-frequency problems. For complex structures with a global loop basis, LF–MLFMA directly based on a loop-tree basis is inefficient and cannot be applied. To solve the problem, LF–MLFMA based on an RWG basis, wire basis, and wire–surface basis for efficiently solving low-frequency problems is developed. But the intrinsic expansion bases are still loop-tree bases.