A performance baseline for the convergence of electromagnetic integral-equation calculations using pulse functions

A parametric study characterizes the residual errors associated with calculating electromagnetic integral equations using pulse-function expansions. To accomplish this, the integral equations are first reduced to straightforwardly computable convergent integrals of one variable. Pulse-function expansions then lead to approximations based on admittance matrices. Construction of the admittances is an order-N operation. Explicitly quantified, contributions by integrand singularities become dominant error contributors if not judiciously treated. For both parallel-plate and rectangular TE^z-mode waveguides, at most thirteen samples per waveguide-mode half-cycle are sufficient to produce magnitude-residual errors that are less than one percent of the calculated quantity