sma end launch for microstrip
In general terms things get fun above about 2 GHz. You will need to model and evaluate the footprint and the connection to your transmission line carefully. Pay attention to the way the ground is connected to the connector housing and model via's if they are in the picture. You describe CPW but you may be considering grounded cpw as well. Unless you are really lucky you may find the dimensions of the transmission line, components installed downstream, and the connector dimensions force you into incompatibility in your model.
I would expect that without too much pain you could get into the -15 to -20 dB range with s11 over a useful bandwidth.
BTW a microstrip could easily work in this situation as well. You might not need to shift to cpw to get a good match.