Computation of MBF Reaction Matrices for Antenna Array Analysis, with a Directional Method

Computing the reduced matrix reaction terms in macro basis function (MBF) solvers for large antenna array analysis, is computationally expensive. A hierarchical structure together with a fast low-rank factorization technique can be used in order to improve the computational complexity. However, the rank is expected to increase with the subdomain size for electrically large problems, hence degrading the performance of the algorithm. Directional methods are used to ensure a constant rank for oscillatory kernel applications by subdividing the interacting region into pyramids. This paper report on preliminary investigations for using the directional cross approximation method to compute reaction terms.