WiFi antenna

I don't own one but my father owns a USB booster (Alpha I think). It works good. Not as high a range as some units with the big external antennas but way better than just his internal antenna. He generally was able to bring in average campground Wi-Fi if there was any. I use a Ubiqity unit like mentioned above and beat his range but it is not as simple a unit as his is. It requires much more programing. The one you referenced looks like a good unit and got good reviews but is probably cheaper due to it being an older unit. It's directional which will mean better range but you have to know where to direct it. The USB units drawback in my opinion is that they usually only work for the computer they are plugged into, but that may be all you need. They are usually simpler to setup and to configure and are very portable, as in you could take it to your car if you wanted to. Some other options like mentioned above can be configured to work as a router also then allowing everything in your RV to use the booster as a private network, but these are usually more permanently mounted with larger more powerful antennas though many can be made to be more portable as those newer, smaller, box size directional antennas aren't as big as the older Yagi style antennas.