# Has someone measured that in the far field of radio waves, the electric and magnetic field oscillate synchronously?

That in near field both fields oscillating 90° displaced is obvious since in antenna rod a lot of electrons will be accelerated and and this oscillation of electric field is escorted by alignment of electrons magnetic dipole moments. Thus oscillation of magnetic field - if strong enough - produces the next oscillation of electric field and so on.

But somehow this two components of EM field were going over to a state - called far field - there both fields oscillation at the same time. In know that Hertz produces sparks and registered this modulation of EM radiation some meters away.

Does he or someone else measure the synchronicity of the two components with amplitudes not shifted 0° to each other and of course both perpendicular to the direction of propagation and not shifted by 90° like in the near field?

Edit because of the comment from KyleKanos: What I'm asking is, has someone measured, that at one moment of time the peak of magnetic component is in the same distance from source as the peak at the electric field. That should be not easy because this peaks are moving with c.

• The translation of this is a bit muddled. Are you asking "How do the EM fields know about when to switch from the alignment in the near field to their alignment in the far field?" Commented Apr 26, 2015 at 16:56
• @KyleKanos: Please feel free to correct my bad English. What I'm asking is, have one measured, that at one moment of time the peak of magnetic component is in the same distance from source as the peak at the electric field. That should be not easy because this peaks are moving with c. Commented Apr 26, 2015 at 17:10
• The experimental difficulty scales with frequency, not with speed of light. Today it's quite "easy" to measure the phase between electric and magnetic components directly well into the microwave regime with suitable antennas, a bunch of amplifiers and a phase measurement bridge (in practice even a simple mixer will do). Commented Apr 26, 2015 at 18:30
• @CuriousOne: Nice. Could you give some sources to read about such experiments? Commented Apr 26, 2015 at 18:50
• You mean you really want me to do a literature search for you? Commented Apr 26, 2015 at 18:51