This simple experiment shows is that even though the R&S watt-meter shows a forward power of 30W and the Bird a reflected power of 30W no power is actually passing through the instruments. (assuming a lossless transmission line)
Power doesn't actually flow - it is EM
energy that is being transferred. All EM energy must necessarily move at the speed of light in the medium because nothing else is possible. Power is the energy per unit time that is passing a fixed measurement point. The power in an EM wave, measured at a measurement point, is ExH.
Does this then mean that there is no such thing as reflected power? I think so.
Consider a one second long lossless transmission line with an SWR of 5.83:1 being driven by a 100w source. The forward power is 200w and the reflected power is 100w. 100w is being delivered to the load.
A one second long lossless transmission line is interesting because if one puts 100 watts into it for one second, the line contains 100 joules of energy.
In the above example, it can be shown that during steady state, the transmission line contains 300 joules, 200 of which are in the forward wave and 100 of which are in the reflected wave. It can also be shown that the 300 joules existing in the transmission line have been sourced by the source but have not yet made it to the load. It is physically impossible for EM energy to stand still or to move at any speed other than the speed of light in the medium. We know that to be a technical fact of quantum physics.
Standing "waves" are an illusion and do not even meet the technical definition of "wave".
Let's take that one second long lossless transmission line and remove the load. For one second, we source a kilowatt RF signal. During second number two, we disconnect the source and you grab one conductor in one hand and the other conductor in the other hand. What happens during second number three? I'll bet it would make you believe in reflected power.
