Hi,
Here’s a link to the ifixit [guide|104807] guide.
In Step.5 of the guide it mentions:
''“On the back of the board we spy the Z-wave antenna (the black rectangle on the left), and some metal contact clips mounted in the case. The board has some coaxial connectors, but seems to be using spring contacts instead—a nice repair-friendly, low wear connection option”.''
Hopefully this is of some help.