RadioBanter - View Single Post - Standing-Wave Current vs Traveling-Wave Current

Walter Maxwell · December 23rd 07, 11:49 PM posted to rec.radio.amateur.antenna

On Sun, 23 Dec 2007 13:34:49 -0600, (Richard Harrison) wrote:

Keith Dsart wrote:
"Therefore, the forward and reverse waves can not be transferring energy
across these points."

A wave is defined as a progressive vibrational disturbance propagated
through a medium, such as air, without progress or advance of the parts
or particles themselves, as in the transmission of sound, light, and an
electromagnetic field. Light, for example, is also calld luminous or
radiant energy. Sound and radio waves are also examples of energy in
motion.

Waves in motion are transporting energy no matter how their constituents
seem to add at a particular point.

Best regards, Richard Harrison, KB5WZI

It appears to me that even with all the successive posts on the subject of power in the standing wave, you all
seem to be missing the ingredient that proves why there is no useable power in the standing wave. It is
because the current and voltage in the standing wave are 90° out of phase. Multiplying E x I under this
condition results in zero power.

In addition to another comment above that implies that reflected power is reactive power, this is not
true--reflected power is as real as forward power. The only differences are that they are traversing in
opposite directions, and that while the voltage and current travel in phase in the forward direction, they are
traveling 180° out of phase in the rearward direction. Multiplying voltage and current while 180° different in
phase results in the same power as when they are in phase.

Walt, W2DU