For those that are interested RF design you may be interested to know that the most recent public release of QUCSstudio now has basic microstrip EM simulation based on openEMS
You can create the layout using microstrip elements either in the schematic editor or direct in the layout and then simulate to give S parameters. The layout can be exported to gds, png, jpg or bmp which I guess could then be used in KiCAD as the basis for a custom footprint
Not open source but free and very useful none the less
Sadly the original QUCS project appears to be dead in all but name, it promised great things. I don’t know what prompted the author of QucsStudio to rewrite the simulation engine and choose not to open source it but it is his choice, none the less QucsStudio is heading towards what QUCS might have been.
BTW, the EM simulation is definitely openEMS, make sure to look on the new web site linked above. Granted, there is no shortage of packages that can do the job but I am not aware of any other low cost or open source solution with the ease of QucsStudio and that is the point.
QUCS works fine for me, great thing to play with RF. I tried Qucs-RFlayout, for simple use cases it looks better than writing scripts for OpenEMS but probably it’s not helpful for structures that can’t be easily autogenerated from schematic.