Weak 3G signal after miplate change

Hello!

I changed the MId-Plate of my iPhone4 (now its black).

Everything works fine:

GSM, WIFI, GPS signals are perfect, but when I turn on 3G, the signal is very weak!

All screws are tighten, all connectors connected.

But: I broke one of the fingers of the lower antenna!

Do you think a new one would solve the issue? (I read that the lower Antenna is only WIFI, wich is fine)