###### Abstract  
A complex cylindrical structure consisting of a group of parallel stratified circular lossy dielectric cylinders, embedded in a dielectric circular cylindrical region and surrounded by unbounded dielectric space, is considered in this paper. The scattering of electromagnetic (EM) plane waves by the aforementioned configuration was studied; the EM waves impinged obliquely upon the structure and were arbitrarily polarized. The formulation used was based on the boundary-value approach coupled with the generalized separation of variables method. The EM field in each region of space was expanded in cylindrical wave-functions. Furthermore, the translational addition theorem of these functions was applied in order to match the EM field components on any cylindrical interface and enforce the boundary conditions. The end result of the analysis is an infinite set of linear algebraic equations with the wave amplitudes as unknowns. The system is solved by the truncation of series and unknowns and then matrix inversion; thus, we provide a semi-analytical solution for the scattered far-field and, as a consequence, for the scattering cross section of the complex cylindrical structure. The numerical results focus on calculations of the electric- and magnetic-field intensity of the far-field as well as of the total scattering cross section of several geometric configurations that fall within the aforementioned general structure. The effect of the geometrical and electrical characteristics of the structure on the scattered field was investigated. Specifically, the cylinders' size and spacing, their conductivity and permittivity as well as the incidence direction were modified in order to probe how these variations are imprinted on scattering. Moreover, comparisons with previously published results, as well as convergence tests, were performed; all tests and comparisons proved to be successful. a 2  
circular conductive or dielectric cylinder embedded in a host cylinder either concentrically or eccentrically [7; 8; 9; 10]. The case of scattering by inhomogeneous cylinders has also been studied [11], while arbitrary polarization and oblique incidence on either dielectric cylinders loaded by strips [12] or dielectric semi-cylinders loaded by ground plane slots [13] have been considered. More recently, scattering by dielectric cylinders eccentrically coated by cylindrical metamaterial shells has been investigated [14]. The most popular method to treat such problems is the expansion of the electromagnetic (EM) field expressions in cylindrical wavefunctions with unknown coefficients, which are found by applying the corresponding boundary conditions and solving the consequent infinite set of linear equations by truncation and matrix inversion [15]. However, various analytical formulations and numerical techniques have been proposed to deal with scattering from cylindrical structures; the latter may be far more complex than the ones mentioned in the previous paragraph. Indicative works are cited below. The computational method of moments has been used to study electromagnetic scattering by perfect electric conductor (PEC) cylinders with arbitrary cross sections and several dielectric layers [16; 17], and an impedance boundary condition of 2 nd order has been employed to examine the effects of different dielectric coverings on PEC cylinders [18], while fictitious filamentary sources have been used to imitate the EM field scattered from a coated cylinder [19]. Scattering from eccentrically stratified cylinders has been addressed by enforcing the boundary conditions directly upon cylindrical surfaces at normal [20] and oblique incidence [21], while a new technique based on an indirect mode matching and 2 nd Green's vector theorem has been introduced to solve problems of EM-wave scattering from complex cylindrical structures such as eccentrically stratified cylindrical inclusions embedded in a host cylinder [22; 23].