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Roy Lewallen wrote:
Although it's not really relevant to the discussion at hand, I believe a valid argument could be made that if a2 isn't equal to zero, then S11 isn't a reflection coefficient at all. It surely isn't the reflection coefficient at port 1, anyway. Actually, it is, Roy. s11 is the *physical* reflection coefficient. For instance, in the following two-port network: source---50 ohm feedline---+---1/2WL 150 ohm feedline---50 ohm load s11 is *defined* as the input reflection coefficient with the output port terminated by a matched load (ZL=150 ohms sets a2=0). s11 continues to be *defined* as 0.5 even when a2 is not zero. s11 = (150-50)/(150+50) = 0.5 Since a Z0-match exists at '+', the reflection coefficient on the 50 ohm feedline is zero. rho = Sqrt(Pref/Pfwd) For a two-port network with a2 not equal to zero, the reflection coefficient 's11' is NOT equal to the reflection coefficient 'rho'. The energy analysis on my web page deals only with physical reflection coefficients. If 'rho' is not a physical reflection coefficient, then it is the END RESULT of a mathematical calculation and is not the CAUSE of anything. If a source doesn't "see" a physical impedance discontinuity, it doesn't "see" anything except forward and reflected waves. Coherent waves traveling in opposite directions are "unaware" of each other. Coherent waves traveling in the same direction merge, lose their separate identies, and become indistinguishable from one another. -- 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! =----- |