ipad mini weak wifi

Like many others I have a major wifi problem with my first gen ipad mini. It connects just fine but if i move more then a foot away from the router it loses connection. Any one know if i can take it apart and change either the antenna or wifi ? if so can any one tell me if there is a better one i can use other then an original ?

yes i tried it on 3 different routers. all the same thing, it has to be with a foot or so of the router. I also noticed today it wont even see the hotspot on my iphone . and it will not wind any of the weaker wifi`s in my area.