Computation of electromagnetic fields scattered by cylindrical targets buried in a medium with a periodic surface

Electromagnetic scattering from a two dimensional, cylindrical, and dielectric object of arbitrary cross-section buried in a lossy dielectric half-space having a periodically rough surface is investigated by a new numerical method. The method is outlined for TMz (horizontally) polarized incident wave.The basis of the new solution technique is that if a target is close to the surface, the electromagnetic fields will be nearly identical to that without the target, except within the region of finite extent near the target. Thus, the current on the surface will be affected only in a finite portion of the surface near the target. The electric field integral equations (EFIEs) for the equivalent currents on the target and the perturbation equivalent currents (the difference currents with target present and with target absent) on the surface are obtained by using this approach and solved by the Method of Moment (MoM) in frequency domain. Then, inverse Fourier transform is utilized to get the time domain signals. The short-pulse scattering results is used to investigate the effects of multipath.