Electromagnetic scattering and radiation by thin wires partially immersed in a homogeneous dissipative half space. Importance of the internal coupling effects

The frequency-domain electrical field integral equation (EFIE) is used to develop an efficient numerical process to treat problems of diffraction and radiating by thin wires. The authors consider geometries partially buried or immersed in dissipative homogeneous media. Triangular patches modeling is used in applying the moment method (Galerkin method) to solve the equation and to obtain a matrix system. Evaluating the impedance matrix elements involves numerical problems introduced by moment method application and calculation of Sommerfeld integrals. These terms are evaluated by a numerical integration procedure along the real axis which is applicable for a large range of parameters. Comparisons of current distribution along the wire in the frequency domain are made with previous results and validated. Numerical results corresponding to an `L´ shaped wire allowed them to highlight the coupling effects between the different parts of the structure according to the frequency, geometric dimensions and electrical parameters of the dissipative media (ground or sea)