Never used these before and getting ready to try them out.  I know there are two antennas and know I can set my goggles for Analog mode, but since I will be useing the USB cable from contolller for link, what is the antenna really needed for?

The antenna on the goggles won't be used for anything since the Mavic Air is not able to connect to the goggles wirelessly. It could be useful when flying other types of drones though (e.g. racing drones).

Hi there, please check the user manual of the DJI Goggles RE from the website: https://dl.djicdn.com/downloads/ ... _User_Manual_EN.pdf, page 8 to page 10, you can know more details about the Antenna, thanks!