Geometry Layout

The design starts with a microstrip over a ground plane (figure 1) and substrate extending to infinity, simulated by the boundary conditions. The substrate used is a material with a permittivity $\epsilon = 5$, approximating that of duroid, a material commonly used in CU-Boulder microstrip fabrication.

  

Figure 1: A view of the microstrip line cross section. The microstrip width varies as it progresses along the line, from 2mm to 6mm or more.

The microstrip is built so that the signal propagates from the source region to the incident measurement and hits the discontinuity. Then the signal splits into reflected and transmitted waves, to be measured by the two probe regions. Initial simulations were done with a 4mm wide microstrip at the far end (figure 2).

  

Figure 2: Top view of the microstrip line.