An Efficient Evaluation of the Self-Contribution Integrals in the Spectral-Domain Analysis of Multilayered Striplines

A very accurate technique to analyze the propagation in multilayered striplines is the Galerkin's method in the spectral domain with Chebyshev polynomials basis functions weighted with the edge behavior of the unknown surface current density on the metallic strips. Unfortunately, such a method leads to the numerical evaluation of improper integrals of oscillating and slowly decaying functions. Recently, a new technique specifically devised to efficiently evaluate the mutual coupling integrals has been proposed by the author. In this letter, such a technique is extended to efficiently evaluate the integrals of self-contribution.