Roy Lewallen wrote:
I'm not seeing Cecil's comments in context, so this might be irrelevant,
but there is a convention involved with the direction of
reverse-traveling current waves. The common convention used in
transmission line analysis is that the positive direction of both
forward and reverse current is from the generator toward the load end of
the line. The consequences of this is that the current reverses sign --
really meaning only that it reverses direction -- upon reflection from
an open circuit (+1 voltage reflection coefficient), and it allows
calculation of the total current as the sum of the forward and reflected
currents. An equally valid convention is to define the positive
direction of both forward and reflected currents to be the direction of
travel. If this convention is used, then the current undergoes no change
in sign upon reflection. But the total current then equals the forward
current minus the reverse current. Either convention will produce
correct results, of course, as long as it's carefully and consistently
applied.

Thanks Roy, the former is the convention usually used for RF
wave analysis. The latter is the convention usually used for
light wave analysis. They are obviously different conventions.
--
73, Cecil http://www.w5dxp.com