Tips

Tip 1: Check copper traces are imported correctly

• nanomesh and gerbv may delete or merge traces in the final mesh.
• Follow visualising geometry to confirm all traces are intact.
• Symptoms include high impedance values in results and a high S11 parameter meaning high input reflections.
• When running geometry pass nanomesh has to convert image of layers to mesh data.
• With insufficient settings there will be deletion of traces or merging of traces.
• Modify nanomesh configuration to fix this.
  • Decrease nanomesh.precision to reduce mesh vertex position error.
  • Decrease nanomesh.minimum_angle to permit more aggressive triangulation.

Tip 2: Fix simulation port and drill offsets

• Currently there isn’t automatic alignment of drill and component positions to the Gerber files.
• Symptoms include high impedance values in results and a high S11 parameter meaning high input reflections.
• Follow visualising geometry to see if vias and simulation ports are placed correctly.
• To correct for undesired offsets in the simulation port location adjust the offset.x and offset.y values in the configuration file as explained here.

Tip 3: Double check port assignment

• Follow visualising fields to see if excited ports have been assigned correctly.
• Paraview visualisation will show if you have any ports swapped based on the excitation signal travel direction and location.
• Additionally it will also indicate any bad connections if the excitation signal does not propagation according to expectations.
• Revisit the following configuration file settings to fix this.
  • Simulation ports
  • Differential pairs
  • Signal traces
• Make sure you are exporting simulation ports correctly.
  • Format of port position file
  • Creating simulation ports in KiCAD 8.0
  • Exporting port positions in KiCAD 8.0