Projection segmentation of boundaries for computing per-unit-length parameter matrices of multiconductor transmission lines using the method of moments

When computing per-unit-length parameter matrices of multiconductor transmission lines by the method of moments, the accuracy and computational costs are largely determined by the method of constructing a subinterval computational mesh on the boundaries of the cross-sections of the lines. Uniform segmentation leads to an excessive number of segments, whereas adaptive mesh reconstruction methods, while providing high accuracy, require repeated formulation and solution of the matrix equation. Development of a single-step algorithm for generating projection subinterval computational meshes based on a priori information for multiconductor transmission lines of arbitrary cross-section, including structures with non-orthogonal boundaries. A projection segmentation algorithm is proposed that uses classification of cross-section domains and rules for transferring segmentation nodes from signal conductors to the nearest grounded conducting layers. A software module implementing uniform, non-uniform, and projection segmentation has been developed. Computational experiments were conducted for 6 transmission lines with the number of conductors ranging from 1 to 10. Comparison with the results of commercial CAD software showed that the relative difference in per-unit-length parameter matrices for the considered examples amounts to a few percent. At the same time, the application of projection segmentation provides up to a 5-fold reduction in the number of segments, up to a 14-fold acceleration of computations, and up to a 25-fold reduction in memory costs compared to uniform segmentation. The proposed algorithm makes it possible, while maintaining acceptable accuracy, to reduce the computational costs of computing per-unit-length parameter matrices of transmission lines by the method of moments, and can be used in multi-variant analysis problems as well as in the development of specialized software tools and their integration into CAD systems.