I'd like to match the impedance on one of my PCB traces.
For this I chose to use TNT Field Solver.
Suppose that the trace itself looks like this (trace width currently set to 0.8128mm = 812.8 micron):
If I use the TNT like this:
It will iterate the trace width to match 50 Ohms, but in this case trace width is recommended to be 3082 micron (>3 mm) which is really huge so I think this is not the right way to do this.
Now I can add a GND plane also to the top like this, but how can I handle the 'air' between the trace and the top GND plane?
I have 2 questions here:
1.) How can I insert 'air' between the trace and the GND plane? (obviously it is not air, but there is no metallic conductor there)
2.) How to include vias in this calculation?
I've included now the ground stiching and the top-layer ground plane, however ground plane fills between the stiching and the signal wire which is not correct. For ground planes it is not possible to set the width or position, so I would need to do something around the red circles here: