Fast evaluation of Sommerfeld integrals for EM scattering and radiation by three-dimensional buried objects

This paper presents a fast method for electromagnetic scattering and radiation problems pertinent to three-dimensional (3D) buried objects. In this approach, a new symmetrical form of the Green's function is derived, which can reduce the number of Sommerfeld integrals involved in the buried objects problem. The integration along steepest descent paths and leading-order approximations are introduced to evaluate these Sommerfeld integrals, which can greatly accelerate the computation. Based on the fast evaluation of Sommerfeld integrals, the radiation of an arbitrarily oriented electric dipole buried in a half space is first analyzed and computed. Then, the scattering by buried dielectric objects and conducting objects is considered using the method of moments (MOM). Numerical results show that the fast method can save tremendous CPU time in radiation and scattering problems involving buried objects.