If you have the white round flying saucer style of antenna it is a Winegard Roadstar 3000. No longer being produced. Airstream must have purchased a truckload of these before production ended because they are still installing them.
You might contact your selling dealer to see if they can get a replacement from the mother ship. I can tell you the Winegard replacement for the Roadstar 3000 is an ugly black thing about 15" in diameter. Yuck. However, as ugly as it is, it has a WIFI upgrade available that fits in the same housing on the roof. If you go that route you want to mount it on top of your A/C cover as it needs to have no obstructions around it to receive signals.
Call your dealer or AS directly. Good luck.