Quick Hybrid Mode Analysis of Microstrip Line with Edge Line Concept and its Application to Discontinuities

From the examination of the fringing fields at the edge of planar lines, we introduce the edge line concept as an alternative boundary condition in the dispersive bidimensional analysis of planar circuits. In this approach, the dimensions of the circuit are kept to their physical values and the edge line boundary condition is substituted to the magnetic wall condition of the equivalent waveguide model (EWM). Application to the calculation of the tscattering parameters of step discontinuities is given and favourably compared to tridimensional analysis and experimental results.