Assessing the error of transmission-line quasi-static analyses by means of a mixed finite element method

A finite-element method (FEM) using a mixed formulation that provides lower bounds for the capacitance coefficients of microwave transmission-line structures is presented in conjunction with a standard formulation that gives upper bounds. The error of a FEM analysis may be assessed with this method. The mixed FEM can be easily applied to any geometry, representing an improved alternative to other formulations giving the same bounds but with certain limitations. Results and other features of the mixed FEM are shown.<>