Efficient EM scattering analysis based on MoM, HSS direct solver, and RRQR decomposition

A novel technique is presented for efficient electromagnetic (EM) scattering analysis based on a double (geometrical and current-approximation) higher order method of moments (MoM) in the surface integral equation (SIE) formulation in conjunction with a fast parallel direct solver for dense linear systems using hierarchically semiseparable structures (HSS). MoM-SIE matrix blocks are replaced by their low-rank approximations obtained by the rank-revealing QR (RRQR) decomposition for memory compression. Numerical example shows a dramatic memory compression using the novel method while preserving the accuracy of the solution.