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Old August 31st 03, 12:26 PM
Dr. Slick
 
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"Tarmo Tammaru" wrote in message ...
"Dr. Slick" wrote in message
om...
However, they don't explain why a lossy line can INCREASE the
reflected power! The lossless line would not attenuate the reflected
wave at all!


They make a pont of the fact that they are *not* violating the concept of
conservation of energy



But they never explain WHY a lossy line can INCREASE the
reflected power! The lossless line would not attenuate the reflected
wave at all!

I don't trust their claims on this.

If you get more power reflected than you send into a passive
network, you are getting energy from nowhere, and are thus violating
conservation of energy.




They also mention that the normalized load impedance Zn=Zr/Zo does
NOT have the same angle as Zr because Zo is complex in the general
case. This may or may not make their example moot.


I don't see the problem. 100 /_30 degrees divided by 2/_5 degrees is 50/_15
degrees. Different phase angle. By general case they mean not the lossless
case.



I believe you mean 50 @ 25 degrees.




And i don't trust their Smith Chart extended out to 1+sqrt(2) for
a dissipative line. Maybe for an active network, but not a passive
one.


No idea. Never had to extend a Smith chart



Do some research, and you will never see an "extended Smith
Chart" for a passive network. Oh, certainly for a active device, for
stability circles and such, but passive networks can never have a rho
greater than 1.




Also, they go from equation 5.12 to 5.13 without showing us how
they got there.


They use the identity e**jx = cos x + jsin x



Yes? And? How did they get the Zo=(Zn-1)/(Zn+1) from this?




As I said out front. The book is copyrighted 1960. There is a certain life
to these things.

Tam



But it seems to be out of print, perhaps with good reason...


Slick