Mode conversion at discontinuities in a microstrip coupled line waveguide

Mode conversion in an asymmetric microstrip coupled line open end is investigated. Surface current distributions on the coupled lines are determined by the method of moments. The matrix pencil technique is then used to split the currents along the lines into forward and backward multiple mode traveling-wave amplitudes. This is used to compute a generalized scattering matrix accounting for the propagation of two quasi-TEM modes. Mode conversion from the even to the odd mode is studied. (C) 1998 John Wiley & Sons, Inc.