"Cecil Moore" wrote in message
t...
Owen Duffy wrote:
Cecil Moore wrote:
simply drop the units of area. The resultant "irradiance"
equation for transmission line power is:

Ptotal = P1 + P2 + 2*SQRT(P1*P2)cos(A)

2*SQRT(P1*P2)cos(A) is the interference term in watts
where A is the angle between the two interfering fields.

Is this what you mean by 'algebraic sum' as in your words 'resultant
disturbance at any point in a medium is the algebraic sum of the separate
constituent waves'?

Of course not. That statement of Hecht's applies to vector
(and phasor) fields. Powers are scalars and must be treated
accordingly.

and hence my recommendation to abandon power as a useful method of analyzing
waves in transmission lines. power is a scalar, you can't add power without
resorting to digging out the phase angles that come from the current or
voltage waves. so really that p-total equation is what happens when you add
2 current waves and then convert back to powers... you cancel out a whole
bunch of Z0 terms but end up having to keep that ugly phase related factor.