#14 Characteristic Impedance mismatch with Keysight ADS calculator

[David Johansen]

I have used your coplanar waveguide calculator and it doesn't match with what we think is correct please look at the picture(file) that I attached. You will see in the bottom left the typical application recommended by Analog Devices. Your coplanar calculator shows 55ohms and the Keysight ADS tool shows 50 ohms. Is there something that I need to do to get the correct measurement? We are going to run a new PCB and I want to make sure I have the correct values.

[Dan McMahill]

I suspect it has to do with correction for metal thickness. I'm curious about what ADS would say with a thin metal, say 0.1 mil. That said I'm going to close this bug and refer to the current tracker on github where I do have an open issue on this topic (coplanar waveguide and thick metal). If you don't mind, please add any updates there (trying to keep consolidated in one spot). In the mean time I'd go with the ADS result.

https://github.com/dmcmahill/wcalc/issues/16