questions about the gnd of the tx2/1

I want to know if the TX2 Gnd is directly connected to the metal heat sink. What is the relationship between the system GND and the heatsink and the WiFi antenna?

Hi, they are same one GND.

We fixed the Jetson heatsink and WiFi antenna on the metal casing of our equipment. The metal enclosure of the equipment is connected to the Earth. We need to separate the system GND from the Earth. Can you give me some advice on how to do it?

Seem no way except unfixing Jetson and antenna to case.