1/R2-Kernel cancelation in classical marching-on-in-time schemes

Cancelation of 1/R²-associated integrals in the numerical solution procedure of the time-domain magnetic field integral equations are explained to halve the computational costs of the classical marching-on-in-time (MOT) schemes in which the delay time is approximated by the barycentric electric distance of the subdomain patches. The new technique improves the accuracy of the MOT as the resulting interpolation coefficients for the calculation of the impedance matrices became independent of the electrical distance of surface elements. Additionally, the analytical closed-form expressions for the evaluation of the remaining 1/R³-associated integrals allow the fast computation of the retarded matrices on demand. The applicability of the scheme to large-scale wave scattering problems is investigated.