How radio waves create the current in antenna in terms of
photons? If it is Compton scattering then why is not changed the
freuency of photons? An elementary explanation, at high school
level: The beam of radio wave photons are coherent, as Vladimir
said. Coherent means that the electric and magnetic field of
each individual photon has a fixed phase with all the others.
When the wave reaches an antenna, some of the photons are
absorbed, pushing the electrons to a slightly higher energy
level (energy h*nu) in the conduction band. Thus it is not
scattering but absorption that generates the current with the
frequency of the incoming beam. It is coherence that , as the
photon is absorbed, pushes or repulses the electrons in step, so
that a current that has the frequency of the impinging beam is
built up. No, it is not a Compton scattering - the electrons in
antenna are not really free. A radio wave is a flux of coherent
photons, they act together, not one by one. Any EMW makes
charges move but bound charges may m