The ACA algorithm in the electromagnetic scatter of multiple target

Being restricted to the computer memory, it is hardly to offer enough memory to the coefficient matrix when the target is too large while applying the MOM. As to this, this paper introduces a new algorithm, the adaptive cross algorithm (ACA), to reduce the memory and CPU time. The present algorithm is purely algebraic in nature; hence, an important virtue of the ACA algorithm is that its formulation and implementation are integral equation kernel (Green´s function) independent [1]. In this paper, the ACA algorithm will be used to study the multi-target electromagnetic problems of small electrical size. Through the numerical experiments, the validity of the present algorithm is certified, and it is concluded that the complexity of small electrical size problems is O(N²) (where O(N²) is the number of unknowns).