Mathematical Modeling of an Open Microstrip Line

Abstract

An open microstrip line (MSL) having sufficiently large dimensions of the screen is modeled by the screened line constructed by the projection method using Chebyshev polynomials. The expressions for the matrix coefficients of the infinite system of linear algebraic equations for the coefficients of the current density expansion on the surface of a strip conductor are presented. Limit expressions for the matrix coefficients are obtained for the screen dimensions going to infinity. The solution to the infinite system of equations is considered in the quasi-static approximation and the application boundaries of this solution are determined. The numerical results confirming the rapid convergence of current density expansions that is theoretically determined are presented. These results make it possible to optimally choose the screen dimensions for modeling an open line.