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Walter Maxwell wrote:
Cecil, when a mismatched line is matched at the input with a tuner the reflection coefficient at the matching point in the tuner is 1.0 when the tuner is matched, thus the re-reflected voltage wave must be equal to that of the reflected wave. My statements are all based in these conditions. That is NOT true of an S-parameter analysis, Walt, which is essentially what Dr. Best is using in his article. In a system with reflections the S-parameter reflection coefficients are NEVER equal to 1.0. How can I make you understand that you and Dr. Best are using entirely different systems of analysis and yours has no bearing on his. Here's your arguments: Steve: "It's a plant." Walt: "No, it's a tree." Steve: "No, no, it's a plant." Walt: "No, no, it's a tree." In the following matched system, the reflection coefficient in Dr. Best's system of analysis is ALWAYS |0.5| and is NEVER 1.0. This is also true for an S-parameter analysis. The only difference between Dr. Best's analysis and an S-parameter analysis is that he didn't normalize his voltages to SQRT(Z0). I presented that fact a couple of postings ago. 100W XMTR---50 ohm line---x---1/2WL 150 ohm line---50 ohm load. Nowhere at no time is Dr. Best's reflection coefficient equal to anything except |0.5|. It is an absolute constant whether the XMTR is off, in the transient state, or in the steady-state. Please read this paragraph over and over until it soaks in. In Dr. Best's system of analysis, the only time that the reflection coefficient is 1.0 is in a system with a short, open, or pure reactance. In his system of analysis, a reflection coefficient of 1.0 NEVER occurs at a matched or mismatched impedance discontinuity if the impedances are not zero or infinite (or purely reactive). Unfortunately, my S-parameter texts are behind in Florida, and I've forgotten the significance of the 'a' and 'b' terms. The HP AN 95-1 ap note is available at: http://www.sss-mag.com/pdf/hpan95-1.pdf The S-parameter reflection coefficients are constant and do NOT change as the reflected power changes. They are the same with no signal applied, or during the transient state, or during the steady-state. The S-parameter reflection coefficient is *NEVER* 1.0 when there exists an impedance discontinuity. You and Dr. Best are NOT USING THE SAME REFLECTION COEFFICIENTS!!!! You and Dr. Best are NOT USING THE SAME SYSTEM OF ANALYSIS!!!! Nothing you say about your system of analysis is relevant to the system of analysis that Dr. Best used. -- 73, Cecil http://www.qsl.net/w5dxp -----= Posted via Newsfeeds.Com, Uncensored Usenet News =----- http://www.newsfeeds.com - The #1 Newsgroup Service in the World! -----== Over 100,000 Newsgroups - 19 Different Servers! =----- |