Hfss Filter Desiging

Hey there, I am a novice in designing filter. I have it as my project. I can't find how to assign ground. In many pdfs i have searched for, they directly say to use substrate and implement the resonators later. Please need your help. May be this is a not worth asking. But as I am a beginner , I need urgent assistance.
With Regards,
Neha

If you just have a substrate and no housing you can select the bottom fact (press 'f') of the substrate and assign it as a PEC (with the option of assuming it is an infinite ground plane) or with material properties as Finite Conductivity and input the conductivity or assign from material properties.

What is considered 'ground' in HFSS will depend on how your sources are excited. For example, on a microsteip line with wave ports you would normally set the integration line going from the bottom of the microstrip line (if it has thickness) to the top of the ground plane (if it also has thickness).

I also think there was a question recently about grounding in HFSS too... https://www.edaboard.com/thread350548.html