View Single Post
  #142   Report Post  
Old June 17th 10, 12:04 AM posted to rec.radio.amateur.antenna
K1TTT K1TTT is offline
external usenet poster
 
First recorded activity by RadioBanter: Apr 2010
Posts: 484
Default Where does it go? (mismatched power)

On Jun 16, 2:49*pm, Cecil Moore wrote:
Ptot = P1 + P2 + 2*SQRT(P1*P2)*cos(A)

where A is the phase angle between the electric fields of wave1 and
wave2. In our case, it will be the phase angle between the forward
wave and the reflected wave at the source resistor.

For our purposes, based on your specifications, we can rewrite the
equation:

Prs = Pfor + Pref + 2*SQRT(Pfor*Pref)*cos(A)

Pfor is fixed at 50 watts. For a 50 ohm load, Pref=0.
For a 25 ohm or 100 ohm load, Pref=5.556 watts.
Angle A is either 0, 90, or 180 degrees depending upon which example
is being examined.


would you care to provide us with the general equation for A given a
complex load impedance and a line length other than a multiple of 90
degrees?