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I'm studying transmission lines and came up with the question why (voltage) reflection coefficient being zero is not equal to maximum power transfer (conjugate matching). I did some search and found out people invented power waves and reflection coefficient of power waves, where being zero is same as conjugate matching.

In Kurokawa's paper, power waves were introduced simply as a mathematical artifact. But this paper https://ieeexplore.ieee.org/document/4358636 provides a "smoother" derivation of power waves.

A few things I have trouble grasping in this paper are from this paragraph. First, it says V+ is a non-reflecting forward voltage wave, then why does it go on mentioning the reflected voltage wave V- at all? Second, what does it "see an impedance" mean in this scenario and how does the reflected wave "see impedance Z_R?

enter image description here

jleng
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  • Maybe [this answer](https://electronics.stackexchange.com/questions/665413/why-does-impedance-matching-in-the-context-of-reflections-demand-that-resistiv/665673#665673) will help you understand why the reflection sees an impedance equal to the characteristic impedance of the feed cable. – Andy aka Jul 21 '23 at 08:34
  • @Andyaka thanks for your reply. Unfortunately I still fail to get it. Would you mind what does “see” the impedance mean in this context? – jleng Jul 22 '23 at 04:06
  • The reflection (reflected voltage and reflected current) have a ratio that is formed by the characteristic impedance jleng – Andy aka Jul 22 '23 at 09:20
  • @Andyaka Thanks! So can I interpret "impedance seen by reflected wave" as the ratio between reflected voltage wave and current wave, while setting the source to be 0 (V-source to short and I-source to open)? And thus we also end up with the Thevenin equivalent shown in the picture? – jleng Jul 24 '23 at 21:10
  • I don't recognize the picture as being meaningful. Sorry. – Andy aka Jul 24 '23 at 23:16

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