Scattering from the Finite-Length, Dielectric Circular Cylinder: Part I - Derivation of an Analytical Solution.

摘要

Given that an understanding of the scattering effects of the cylinder is important in characterizing the electromagnetic responses of tree structures, in this work a closed-form, approximate formulation is derived for the scattering matrix of the finite-length, dielectric circular cylinder. The solution is obtained by applying the modal (or eigenfunction) expansion method in conjunction with the volumetric equivalence principle, and supposes that the internal fields of the finite-length cylinder are the same as those of the infinite-length case. The theory is first developed for the scatterer located in free space. Subsequently, the problem of the scatterer located above a finite-conducting ground is considered by employing a multiray technique in which the total scattering response is calculated by coherently summing the direct response and the single and double ground bounce contributions. An arbitrarily oriented cylinder is treated by augmenting the solution with appropriate coordinate transformation matrices. This study is intended to facilitate the development of a discrete scatterer approach for characterizing the scattering from tree canopies.