View Single Post
  #6   Report Post  
Old August 28th 03, 12:41 AM
Tarmo Tammaru
 
Posts: n/a
Default


"Reg Edwards" wrote in message
...
=================================


Tam, who are "They" ?

They were MIT EE professors. I think Fano has written a more recent book on
this. MIT is often considered to be the best engineering school in the US.
(Keep forgetting you live "over there")

You are making me work my tail off trying to understand just what they did.
You have a line of impedance Zo with load Zr at point z=0. Normalize,
Zn=Zr/Zo. Since the angle of Zo is within +/- 45 degrees, the angle of Zn is
within +/-135 degrees. He draws some vectors and decides maximum gamma is
when the angle of Zn is +/-135. He solves for gamma^2, takes the square
root, and ends up with gamma =

1 + SQRT(2)

I couldn't massage the numbers just right, but the decimal number I got
suggest that max Gamma occurs when

Zo = k(1 - j1)
Zr = jkSQRT(2) k is the same k

He goes on to say that as you move away from z=0, the reflection coefficient
becomes smaller by e**2alpha|z|

This is probably a never ending discussion, but I wanted to point out that
these guys don't think there is anything wrong with your gamma of 1.8 ;
especially since Slick brought it up again. I do not want to retake Fields &
Waves

Tam/WB2TT