(Dr. Slick) wrote in message . com...
Actually, my first posting was right all along, if Zo is always real.

From Les Besser's Applied RF Techniques:

"For passive circuits, 0=[rho]=1,

And strictly speaking: Reflection Coefficient =
(Zload-Zo*)/(Zload-Zo)

Where * indicates
conjugate.

But most of the literature assumes that Zo is real, therefore
Zo*=Zo."


Fascinating... Please have a look at the following reply I got from
Besser... I still wish people would go through the simple math
themselves, and make up their own minds what's correct and what isn't.
I gather that Slick has made up his own mind, though see no evidence
that it's on the basis of the simple calcs from what I believe he
already agrees with. Oh, well, not MY problem. (This is twice now,
recently, that I've followed up on other people's references and found
them to be at best questionable in some way.)

Cheers,
Tom

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Hello Tom-

Thank you for your message. I do not know which specific course was
referenced by the person you mentioned in your message, but I did
check
the notes for our more popular course which covers linear RF circuits.
In the manuals for that course, the formula is given as you described,
except that the Zo term in the numerator is _not_ the complex
conjugate.
Thus the formula in the manual reads:

Gamma = Vr/Vf = (Zl-Zo)/(Zl+Zo)

This is in agreement with Guillermo Gonzalez's text, "Microwave
Transistor Amplifiers," which is one of the references used in writing
the course.

Please let me know if this information addresses your concern.

Have a good day.

Regards,

Rex


From: ]
Sent: Thursday, August 21, 2003 11:11 AM
To:
Subject: Other concern/question


Below is the result of your feedback form. It was submitted by
) on Thursday, August 21, 2003 at 14:10:53
------------------------------------------------------------------------
---

name: Tom Bruhns

body: I have recently seen someone attribute to Besser Associates
training a formula for reflection coefficient at a load Zl as Vr/Vf =
(Zl-Zo*)/(Zl+Zo), where Zo* is the complex conjugate of the line
characteristic impedance Zo. I'm curious if this is actually what you
teach, as it is counter to what is commonly in texts, and is also
counter to the commonly accepted boundary conditions on a TEM line at
such a load.

Yours in the interest of accurate models,
Tom Bruhns
--------
....
Rex Frobenius
Engineering Director
Besser Associates
650-949-3300
650-949-4400 FAX

www.besserassociates.com

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