Ditto some of the replies above...if there wasn't an IC board inside your remote key...it may be an aftermarket replacement remote key that has a transponder chip inside of it (to enable EWS).
BTW, the "antenna" found on the IC board is not for EWS...its for transmitting the 315 MHz or 433 Mhz RF signal for FZV & DWA (central locking & anti-theft alarm siren system). The EWS antenna is located around the ignition cylinder...and is called the RING ANTENNA.
Depending on build date...a
125 KHz AM signal is sent
from either the Transmitter Receiver or the EWS control module
to the Ring Antenna..that is how EWS and the keys (remote & non-remote) communicate.
Double check the inside of the remote key...or go back to where it was damaged...and make sure that the EWS transponder chip didn't fall out. You DO NOT want to lose it if there's one inside the remote key. The vehicle WILL NOT start without it.
(unless something we don't know has occurred...and EWS has been removed, re-arranged, or disabled)
The original BMW remote key (for your model year) would look like the illustration WPoll posted & the EWS transponder is soldered to the IC board. But an aftermarket (replica) remote key could have the autonomous EWS transponder chip (like the old style remote & non remote keys)...see pic below...the EWS transponder chip is the little black thingy: