Theoretical and Experimental Investigation of Open Microstrip Gap Discontinuities

A theoretical analysis of open discontinuities in microwave planar circuits using integral equations technique solved by the moment method is described. Characterization of the dicontinuity by an equival ent scattering matrix is then accurately evaluated from the determnation of the current distribution along the line containing the discontinuity under different load conditions. An experimental method, which is capable to determine directly the discontinuity equivalent circuit parameters, is proposed. A good agreement between theoretical and experimental results is reported.