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.
--
73, Cecil http://www.w5dxp.com