Weak wifi signal after upper antenna flex cable replacement

I recently replaced a screen on a iphone 4s when the screw that holds down the wifi cable was stripped. When i tried to remove the stripped screw i accedently teared the whole wifi cable. I finaly got the screw out and i ordered a new flex cable. I replaced the flex cable and the wifi worked again. The wifi works great, but when i go a little far away from my router the signal is a little weak. My brothers iphone 4s has 2 in signal but i only get 1.

Anyone have any idea what the problem could be?