hfss ground
Directions from the file:
Wave Port Size
The standard recommendation for most CPW wave ports is a rectangular aperture
Port width should be no less than 3 x the overall CPW width, or 3 x (2g + w)
Port height should be no less than 4 x the dielectric height, or 4h
If no convenient ‘solid face(s)’ meet the above sizing requirements, draw a 2D rectangle for the Port.
Wave Port Location
The wave port should be centered horizontally on the CPW trace
If the port is on GCPW, the port bottom edge should lie on the substrate bottom ground plane
If the port is on ungrounded CPW, the port height should be roughly centered on the CPW metal layer
Wave Port Restrictions
As with all wave ports, there must be only one surface normal exposed to the field volume
Port should be on exterior model face, or capped by a perfect conductor block if internal
The wave port outline must contact the side grounds (all CPWs) and bottom ground (GCPW)
The wave port size should not exceed lambda/2 in any dimension, to avoid permitting a rectangular waveguide modal excitation
Added after 5 minutes:
A better idea. Here's the file, compressed to 456k (that should be small enough right?)