ACCURATE SOLUTION OF WAVE-GUIDE MODEL OF MICROSTRIP DISCONTINUITY WITH THE USE OF BASIS FUNCTIONS WITH EDGE CONDITIONS

The problem of scattering from a microstrip step discontinuity is anal yzed by an integral equation technique with the use of basis functions that include the edge conditions. The presence of magnetic walls in t he waveguide model of the microstrip line makes it more convenient to expand the tangential magnetic field at the interface, instead of the tangential electric field as in the case of metallic waveguides. The p roblem of relative convergence is not encountered as the modes of the two waveguides enter only in the computation of the inner products tha t are tested for convergence. Results for the reflection coefficient a nd the magnetic field at the interface are presented and compared with available data to demonstrate the accuracy and efficiency of the appr oach. (C) 1996 John Wiley & Sons, Inc.