What are mobile phone FM antenna and GPS?

The two are different. FM refers to FM radio, and GPS is a satellite navigation function. In other words, the original back cover is definitely much better than the non-original one in receiving radio and satellite signals. But this does not affect the mobile Internet access. Because mobile Internet access is realized through GPRS network, which means it has something to do with your mobile phone card. So if you don't need navigation, it doesn't matter if you buy your own back cover. A radio can also be used as a receiving antenna through headphones.