I’m new to coplanar waveguide pcb layouts, and to do this I am using KiCad. I want to make this RF circuit to have 5 mil clearance around all the traces, and I’m laying down fresh (no netlist pulled in from a schematic). Whenever I try to fill a copper zone surrounding a trace, I never get a spacing (clearance) between the copper plane and the trace. Instead it looks like the copper plane is engulfing the trace. Any advice? I am trying to use a .005" clearance
This could be because of your minimum clearances set in the Design Rules dialog (“Design Rules -> Design Rules” menu on my version). The default is 0.01, you should try changing that to 0.005. Also note that you should ensure that your board house can handle that, otherwise, you might not get the desired results on your PCB (for instance, the rules at OSHpark are 0.006/0.006)
You will need to play around with the settings, but you may also need to change the Global rules so it accepts any changes to the default rules. Alternately, you can add a Net Class that has special rules (but would still require a change to the global rules).
Chris I think you hit the nail on the head. I changed the defaults around, made the tracks fill in solid (so I could measure the distances correctly), and set the desired values in the copper pour property fields. Got it to work! such is life as a n00b…
I’m the farthest thing from an RF expert available, but also make sure you get the stackup you need from SpeedyPCB and that they can do what you want. I do know that some people report getting good quality boards for RF from OSHpark.