WiFi Quit Working

I have a Dell Inspiron 5559. The WiFi just quit working. It works at 100 mbps when wired to a gigabit ethernet router. I assume this means it is limited by a 10/100 T ethernet capability.

I also assume installing a WiFi dongle will restore my connection to the router, but I have a couple of questions:
1. As I don't want to take up anothe USB port,is there such a thing as a WiFi dongle that plugs into the Ethernet jack on the laptop?
2. If I install a dongle (USB or rj45) that supports gigabit speed, will I still be limited to 100 mbps?

Any help would be appreciated.

 

I have an inspiron 5559. Very nice laptop. Wife took it away from me. You can try reseating the wifi card. It is easily accessable under one of the removable panels on the back. Sometimes with chip creep they just need to be reseated. I have never seen a WiFi dongle that plugs into a ethernet port. I think you will still be limited to 100 mbps by the laptop. Maybe someone else would be better qualified to answer that. Internet speeds are screwy and they depend on alot of things.