Accurate numerical solution of coupled integral equations for microstrip transmission line

A direct and numerically efficient method for calculating frequency-dependent phase constants of even and odd hybrid modes of the microstrip transmission line is described in the paper. The convergence of the numerical solutions obtained is investigated. It is shown that the accuracy of these solutions depends highly on the way in which the truncation of the infinite matrix equation is performed. The possibility of defining the relative convergence is suggested together with the mode of its elimination. Conclusions on the regularities of behaviour and the sequence of appearance of hybrid modes are deduced from the complete spectrum of eigenvalues of corresponding LS and hybrid modes.