Charlotte Blair
Ansys Employee
If the loss tolerance is a critical component of your design, you may want to select a PCB material that may have a tighter loss tolerances at this microwave frequency. With that said it is important to know the effective permittivity that the trace will see as the permittivity above the trace will assumed to be air and the trace at some frequency about 50 GHz in the board dielectric may have a range of frequency dependent values. Knowing these values you can use a transmission line calculator and simulation tool to get the correct trace width.