Antenna

[Jean]

What limits the radiated power from an antenna(properly matched)
connected to a signal generator ?

 

[Art]

Power input to antennea, effective gain of the physical antennea array,
possible absorbing surroundings near anteaaea, type and length of feed line,
condition of connectors tpo source and active elements. Given a particular
signal strength input to the antennea and a good connection (you indicate a
good match), the effective radiated power could effectively approach 90% of
that supplied.