A NEW NUMERICAL-METHOD FOR ROUGH-SURFACE SCATTERING CALCULATIONS

A new approach to solving the magnetic field integral equation (MFIE) for the current induced on a infinite perfectly conducting rough surfa ce is presented, By splitting the propagator matrix into contributions from the left and from the right of the point of observation, a secon d kind integral equation can be formed with a new Born term and a new. kernel, Following discretization of this new integral equation, the u nknown currents can be determined more rapidly and with significantly less storage requirements than conventional LU decomposition; where th e time saving factor is roughly N/3 where N is the number of current s amples on the surface and the usual storage requirements associated wi th matrix inversion are eliminated, While the new Born term is usually adequate for scattered field calculations, the new discretized integr al equation can be iterated to any desired accuracy with no apparent c onvergence problems, Results are presented for one-dimensional rough s urfaces with rms heights exceeding one wavelength and rms slopes excee ding 40 degrees which illustrate the robustness of the new Born term.