Dual formulations for error estimation in non-uniform transmission lines

A time domain discrete model for nonuniform transmission lines, based on a complementary formulation of the transmission line equations, is considered By recasting the line equations in terms of flux and charge, one has to di scretize alternatively only one of the two equations, the other being exact ly verified. This approach has been widely used in electromagnetics to eval uate the discretization error. With reference to simple examples, we show h ow the error estimation can be used for a selective meshing of the line, le ading to much better approximation with the same computational effort.