pcb-rnd offers three classes of tools:
It is possible to design a high frequency board without using any of these, but using these features can speed up the design process and can help making sure the resulting board fulfills all high frequency related requirements.
Layer groups have attributes. Make sure you have set at least thickness on all copper and substrate layer groups and dielectric on all substrate groups. Easiest way to do this manually:
Most high speed or high frequency boards will have transmission lines which will require to follow an exact geometry (trace width and clearance). The easiest way to do this is using routing styles:
It is possible to get pcb-rnd do both of the above semi-automatically, using a calculator dialog box, using the imp_setup user script from edakrill. The advantages are that it makes it much easier and faster to set up layer group and routing style properties, plus there's no room for copy&paste error while manually coping data. It can also be used to look at current settings and calculate approximate impedances.
Some transmission lines require via fencing: post-wall waveguides, laminated waveguides. There's an extended object for making it very easy to draw and maintain line-of-via objects, removing the step of manually creating and moving each via.
The following DRC scripts can help checking high speed designs:
It is possible to use OpenEMS to simulate parts of the board. TODO: figure how this can be used for transmission lines.