Is lower the electrical field intensity in a point where an antenna is receiving these electromagnetic wave?

Question

I want to know how vary the electrical field intensity in a point of space when an antenna receive that signal or not.

Answer 1

Yes, the EM field does decreas slightly. Any signal received by the antenna and passed on to a 'receiver' will contain some small amount of energy and that energy has to come from the field. But, in practice, it's pretty much impossible to measure it since it's only in the range of a few picowatts.

However..... There have been serious proposals made about generating very high-powered microwave signals from an orbiting satellite and directing them to 'antenna farms' in the ocean where enough energy could be extracted from the field to power small electrolysis cells to electrolyse water and generate hydrogen for fuel.

Doug