Full-wave analysis of microstrip transmission lines of polygonal cross-section

In this contribution the analysis of propagation in perfectly conducting microstrip transmission lines with arbitrary polygonal cross-section is formulated as electric field integral equation (EFIE) in the spectral domain. By means of Galerkin´s method with analytically Fourier transformable expansion functions factorising the correct edge behaviour of the unknowns, quick convergence is achieved and the coefficients of the impedance matrix are reduced to single integrals that can be efficiently performed. Therefore the presented method is particularly suited to the accurate and efficient analysis of propagation in high-speed interconnections in integrated circuits, in which the strips thickness cannot be neglected, and often the strips have a trapezoidal cross-section due to the etching undercuts or as a result of the electrolytical growth process.