Connect android phone to WAN port of router (not lan)

I would like to connect my phone to a router so that I can share its internet connection among the devices in my house. How do I connect the phone to the WAN port of my router so that the router is 'getting its internet' from the phone? Will a normal microusb to ethernet adapter do it, like this one? (http://ift.tt/1FYmirA)

I have a tethering plan, and a spare phone I am not using, which is why I am doing it this way and not with a dongle and usb router. Some of the devices I want to connect don't use wifi or will just work better with wired connections, which is why I want to attach the phone to the router via a cable.