Planar Multilayer Substrate for a stacked patch antenna

Hello.

I want to investigate the effects of putting two types of patch antennas on top of each other. 

I have followed the example guide on how to make a patch antenna using the planar Multilayer infinite substrate. 

If I were to want to put a second substrate and antenna on top of the example, is there anything I need to watch out for in order to ensure accurate results? Is it as simple as adding another substrate layer using the Planar Multilayer Substrate and drawing another patch on top?