The RadarBox receiver is connected to your PC using a USB cable with a standard PC connector on one end and a mini USB connector on the other. The USB cable comes with the RadarBox.
Here is the back of the RadarBox:
Close-up of the USB socket:
The Supplied antenna has a male SMA connector which fits onto the female SMA connector on the back of the radarBox receiver.
Below: Close up of the antenna connection (SMA Female):
If you already have an antenna that is suitable for the UHF frequencies that Mode S signals are transmitted on, then you will need an adaptor.
Below: Adapter to allow an external SBS-1 BS1100 antenna to be connected to the RadarBox receiver - BNC Female to SMA Male