Characterization of the Validity Region of the Extended T-Matrix Method for Scattering From Dielectric Cylinders With Finite Length

Abstract

Abstract-The T-matrix approach is effective in analyzing electromagnetic scattering from finite scatterers. Yet for scatterers with extreme geometry, this approach may fail. One example is its inability to analyze scattering from dielectric cylinders with large aspect ratios. To deal with such difficulty, recently we proposed a method based on an extension of the T-matrix approach, where a long cylinder is hypothetically divided into a cluster of identical sub-cylinders, for each the T matrix can be numerically stably calculated. Special care was paid to fulfill the boundary conditions at the hypothetic surface of any two neighboring sub-cylinders. The resultant coupled equations are different from that of multi-scatterer theory. The model results were in good agreement with experiment data available in the literature. However, the validity region of the proposed method was not fully characterized. Now we have developed and validated a method of moment (MoM) code, and are in a position to carry on the task of characterizing the validity region. The proposed method is found to be applicable to dielectric cylinders of arbitrary length as long as the T matrix is attainable for the elementary sub-cylinder. The conditions for the T matrix to be numerically stably calculated in terms of the equivalent volumetric radius and relative dielectric constant are also empirically obtained.

Microwave Scattering and Absorption by a Multilayered Lossy Metamaterial --- Glass Cylinder

“…The function H (2) (βρ) at infinity ρ → ∞ disappears. If π α 0 one has to take for the root another value β = − |β| exp(iα/2).…”

“…n , B (2) n are the unknown coefficients which must be determined. Outside the cylinder only the second kind Hankel function satisfies the radiation condition.…”

“…Here H (1) n (w) is the Hankel function of the n-th order and the first kind, and H (2) n (w) is the Hankel function of the n-th order and the second kind. w is the argument k 2 εµ − h 2 ρ of functions, and h is the longitudinal propagation constant.…”

“…The stream of new scattering problem articles shows the actuality of the topic. EM scattering by dielectric and metal cylinders is a classical problem in EMs and has been investigated by many researchers [1][2][3][4]. An iterative algorithms based on the T -matrix approach for the EM scattering by dielectric cylinders with infinite and finite length is given in [1,2].…”

“…Various methods have been developed to treat diffraction problems such as the T -matrix approach [1,2], method of moments [5], Finitedifference time domain (FDTD) [10], Finite-difference frequency domain (FDFD) [4,11], integral method [9] and method of partial areas [3,7,8].…”