Analysis of Electromagnetic Scattering from Dielectrically Coated Conducting Cylinders Using a Multifilament Current Model

A method of moments solution is presented for the problem of transverse magnetic (TM) scattering from dielectrically coated conducting cylinders. The solution uses fictitious filamentary electric sources of yet unknown currents to simulate both the field scattered by the cylinder and the field inside the dielectric coating. So constructed, the simulated fields are forced to obey the boundary conditions, namely, the continuity of the tangential components of the electric and magnetic fields across the air-dielectric interface and the vanishing of the tangential component of the electric field at the perfect conductor, at selected sets of points on these respective surfaces. The result is a matrix equation which is readily solved for the unknown current. These currents can in turn be used to determine approximate values for the fields and field-related parameters of interest. The procedure is simple to implement and is general in that cylinders of smooth but otherwise arbitrary shape and coatings of arbitrary complex permittivity can be handled. A few illustrative examples are finally considered and compared with available data. The results demonstrate the efficiency of the suggested solution.