Talk:Impedance matching/Archive 2

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Archive 1 Archive 2 Archive 3

Complex conjugate match for maximum power transfer

If someone wants to flesh out the conjugate case, it is easy to understand in the narrow band situation. When operating at a narrow band frequency, any impedance can be modeled as a resister in series with a reactance. Conjugate matching simply means that you set the reactance that you control to be equal magnitude and opposite sign of the fixed reactance that you are matching. Effectively, you are making the fixed reactance go away by resonating it out of the circuit. What you have left is a resistor that you optimize the same way you optimize when the impedances are purely resistive. For example, suppose the characteristic impedance of a coaxial cable is 50 - 2j ohms at 100 MHz. That is equivalent to a 50 ohm resister in series with a 0.8 nF capacitor. The conjugate load would be 50 ohms in series with a 3.2 nH inductor. Constant314 (talk) 14:02, 18 April 2020 (UTC)

Recent additions

Constant314 deleted:

   1. Coefficient derivation for Reflection caused mismatch on transmission lines
   2. Coefficient derivation for Source Load Impedance Mismatch caused suboptimal match
   3. The warning to not confuse both coeficcients, as in ATIS and IEC glossary.

His reason given was:

   " Not a valid derivation since it presumes the result for optimum current. But not needed. "

Constant314 somehow seems to dislike the subject "Maximum power transfer", see choice of his earlier wording "If someone wants to flesh out the conjugate case ..."

Personal opinion should, however, not deteriorate the quality of a page by deleting disliked relevant aspects.

  • Please do not try to infer other editors likes and dislikes. That can lead to offended feelings (not in my case this time). This is an example of invalid reasoning that led to an incorrect conclusion. I do care about “maximum power transfer” but I do not have access to the required reliable sources. Hence, I offered the outline (or skeleton) of the explanation, hoping that someone else would “flesh out” the explanation (with sources, but I didn’t say that). “Flesh out” is an idiom meaning “to add substantive material.”Constant314 (talk) 23:44, 8 April 2022 (UTC)

Facts are:

1. "Impedance matching", the subject of the article, requires knowing, how much mismatch is present in a given design. Most practical designs are first mismatched, until some matching took care. The deleted coefficients can rate the value or need of matching efforts. Thus they are not redundant, but needed to know, i.e. before purchase of matching components.

2. The deleted Source Load Impedance Mismatch Coefficient derivation is not redundantly presuming the result. Rather it derivates a rating figure expressing the power transfer quality of a match.

The only two only presumptions used, are:

  a. the Maximum Power Theorem 
  b. Ohm's law for complex impedances

In any Source Load Impedance Mismatch Coefficient derivation both are necessary requirements. Neither one was re-derivated. So that's not "presuming the result".

The claimed "presuming the result for optimum current" is no presumption, but optimum current is a calculated provisional result in the process of the derivation - not the result itself, nor a presumption used. The maximum power theorem - though being one single (special) solution of the derived Coefficient of course, as everything else would be a contradiction, is not the result. Rather the coefficient derived for dealing with mismatch correction evaluation is the result.

To my best knowledge, wiki so far nowhere else has any derivation of the Source Load Impedance Mismatch Coefficient. Right? Even if it had: It exactlyly belongs to the subject "Impedance Matching" - where else? So at least a link would be the minimum one can expect on this Impedance Matching page.

There is already existing derivation for the Reflection Coefficient. That's nothing new. I provided another one, exactly fitting the circuit and description used on the respective wiki page "Reflection Coefficient". But Constant314 deleted that, too.

The reason for having both derivations side by side on the subject "Impedance Matching" is to show the difference between the two, so unfortunately confused by ATIS and IEC glossaries. The link to them also was deleted. These misleading glossary statements, probably read by many readers, also taught in lectures, need proper correction, too. At least it was taught at our local Univesity of Applied Sciences, Augsburg, by Prof. Dr.-Ing. Reinhard Stolle. He wrote, and I quote verbally from his email to me: "This is what we teach". But then he checked it by derivation hinself, concluding, that equating both coefficients is incorrect.

So Wiki should show the correct difference, instead of covering up misleading errors. Here are the links: [1] It equates both coefficients as being the same. [2] It implicitely uses the reflection coefficient in the return loss equation, and suggests, that the equation given applies to source load imedance mismatch, too.

Such errors can occur. Nobody is perfect. But errors should not persist. It is necessary to correct errors. Wiki is a good place to correct mislead public knowledge.

I will - after first giving Constant314 a chance to undo his premature deletion himself - have to reload the page subject relevant matter. DJ7BA (talk) 15:04, 8 April 2022 (UTC)

References

  1. ^ "ATIS glossary: Reflection Coefficient".
  2. ^ "Return Loss, IEV ref 702-07-25 en".
I agree with Constant314's reversion. The added material was badly written, hard to understand, and in an unencyclopaedic style with multiple bolded instructions to the reader. A clear case of WP:NOTTEXTBOOK if ever there was one. And not a very good textbook at that. SpinningSpark 16:22, 8 April 2022 (UTC)
Per WP:RIGHTGREATWRONGS, wikipedia is not the place "to correct mislead public knowledge". Wikipedia is a place to paraphrase reliable sources. If you are going to state that authoritative sources are wrong, you need to paraphrase a reliable, published source. Constant314 (talk) 17:26, 8 April 2022 (UTC)
Ok, accepted, though with regret,
The good thing in the derivation is: It's math speaks an easy to follow language, that certainly readers interested in this subjetc can follow.
Math doesn't need "reliable sources". Nobody needs authoritative sources like Trump or Putin to confirm that 2+2 = 4.
The well known ATIS or IEC is no garantee for correctness. Math is. DJ7BA (talk) 17:45, 8 April 2022 (UTC)
I used to have the same opinion, but in Wikipedia, we require reliable sources for math. We do allow simple math, such as conversion between feet and meters. Anything more complicated is original research (WP:OR) unless there is a WP:RS. Sometimes we allow a little bit of algebra without a source, but it requires a consensus of the involved editors. Constant314 (talk) 17:59, 8 April 2022 (UTC)
As a newcomer in wiki I may need help, but deletion is no help. It rather is felt like intented provoking.
So why not simply change the bold that you warry about - instead of deleting precious to the subject's reader contents.
The contents is, what matters.
As meanwhile already again deleted, I also add this:
There are applications requiring maximum power transfer, not bridging:
Think of extremely small signals picked up by a (because of long wavelength and limiting property size for antenna) electrically short reception antenna. You certainly don't want to unnecessarily loose any portion of the weak signal being covered by noise.
Or think of extremely low signals picked up by a sensor.
There are benefits for different applications. Deleting pertinent info is not the answer. But allowing readers the best choice is. DJ7BA (talk) 17:33, 8 April 2022 (UTC)
If I see something added to Wikipedia that should not be there, my first objective is to protect Wikipedia. I may fix it if it is easy to do so, but if not, then I revert it. In this case, there was too much to fix and in fact should not be in Wikipedia by policy. We do not just throw stuff out to the readers and let them sort through it. Well, actually, that does happen, but it is bad practice. The existence of bad practice elsewhere is not a justification for more bad practice. It is a justification to fix the existing bad practice. Constant314 (talk) 18:06, 8 April 2022 (UTC)
"Hard to understand"?
What is your, and what is the expected "Impedance matching" (or redirected "Impedance mismatch" reader's math background?
The wikilink provided "relative difference" may help. That it is not hard to understand - or is it really?
And is this not encyclopedic style to explain:
"Gamma is the relative difference between an actual value and the optimum value of a quantity for a specified goal"
  • That is an incorrect assumption. This is an example of why math requires a reliable source. Gamma is the voltage ratio of the reflected wave or signal to the incident wave or signal.Constant314 (talk) 23:52, 8 April 2022 (UTC)
That's no harder math then:
A nominal 220 pF capacitor measured 231 pF. That's 5% off the nominal value, or. expressed as factor: 0.05. This is a relative difference - in this case with respect to a nominal value. That's easy.
Likewise, the coefficient Gamma also is a relative difference - however in that case with respect to the known optimum value for a specified goal (here: Reflection suppression or best power transfer).
Too hard to to understand?
How would you better express that in wiki style? I am open for improvement of the page. DJ7BA (talk) 18:18, 8 April 2022 (UTC)
Readers aren't expected to have any math background, especially in the introductory sections of articles. The bigger problem, though, was that your additions are all original research. This just isn't the kind of material that Wikipedia hosts - we are specifically not supposed to be a host for new works. MrOllie (talk) 18:28, 8 April 2022 (UTC)
The derivations confirmed the already existing Gamma equations. Buit these meanwhile disappeared also. Why?
As you can see: New is not the mismatch. nor it's Gamma equation.
Also: Wiki is full of alll math level derivations.
That is what readers can expect: Provable to be reliable info to the point.
My derivations are well understandable. But you must follow the wikilink, and, should it be necessary, read twice. 2001:16B8:2D80:7C00:28E5:3AFF:C907:B5E (talk) 18:39, 8 April 2022 (UTC)
Long-winded derivations are not suitable material for a general encyclopaedia article, this is why we have the WP:NOTTEXTBOOK guideline. Alright, an article on a mathematical proof might usefully contain the proof, but generally, only the result and what it was based on are needed in the article. Besides which, you are wrong that a mathematical rationale does not need a source. Yes it does, firstly because it is very easy to make mistakes, which can often be subtle, no matter how many Wikipedia editors you get to check your logic. But more than that, a source is needed to show that your approach is used by authoritative sources. If it isn't used anywhere else, then it has no place on Wikipedia either. That's what is meant by No original research. For instance, can you point to a reliable source that contains the phrase "derivation by actual and optimum currents" in the context of this topic? SpinningSpark 19:22, 8 April 2022 (UTC)
I agree with the others that this addition by DJ7BA was not appropriate for multiple reasons, including WP:NOTTEXTBOOK and WP:NOR. The extensive derivation was not taken from major works published about the topic. It's too much detail for this general overview article. Also, DJ7BA introduced the term SLIM which is not widely used. Binksternet (talk) 19:52, 8 April 2022 (UTC)
Quote:
"Yes it does, firstly because it is very easy to make mistakes, which can often be subtle, no matter how many Wikipedia editors you get to check your logic"
True, indeed: You don't have to go to other articles:
Here you write:
" A conjugate match is different from a reflection-less match when either the source or load has a reactive component."
If you would not have deleted the proven by derivation equations:
| \Gamma_{SLIM} | = \left |\frac {Z_L-{Z_S}^*} {Z_L+Z_S} \right |
and
|RC| = |\Gamma | = \left |\frac {Z_L-Z_S} {Z_L+Z_S} \right |
you could find the error included in that jumping to conclusion statement:
Example: Let Z_S be 50 Ohm, and Z_L be 100 + j 200 Ohm.
Result: |RC| = | \Gamma_{SLIM} | = 0.8246.
I purposely only show the result - not to bore you with calculation, as you so prefer. Does your math backgroung permit to check this result by calculating yourself?
Well, maybe, yes, you can do that. If not: Fine. But why not let others, who can contribute beyond the first editor's limit, fill the gap?
Is a limited math horizon of a first editor of an article, describing a physical subject that necessarily implies some math relations, enough reason to let other pertinent contributors not go beyond that?
I think no. Instead, Wiki's strength is constant improvement by many Contributors, not for pampering the pride of the first and maybe a few bubble friends of him, by deletions of others.
If you think, you prefer pampering the first and his bubble friends is to be preferred, as it simply cannot be that the first one has not included enough know-how:
So be it. I then will no longer bother you at all. Let the reader world believe your pride and that of your supporters more, instead of improvement and permitting earnest "Impedance Matching" readers to follow 100% proven by derivation equations.
So: Either the subject is duely described - and I promise - with your appreciated help - to do my best in overcoming a wiki newcomer's admitted misconceptions about how wiki articles must be done - or:
You finally have pissed me off. It's Your choice:
Permit pertinent equations with derivation - as low-level undertsandable as possible (I promise to do my best to improve it in that respect) - or not. 2001:16B8:2D3C:9900:6D81:B329:BBD2:C376 (talk) 08:14, 9 April 2022 (UTC)
Assume good faith is a key behavioural guideline here, and your constant aspersions about the mathematical ability of others shows you are demonstrating very little of it. I'm pretty sure that everybody taking part in this discussion is degree educated in a technical subject. Just because we don't think articles should be stuffed full of maths, doesn't mean we don't understand it. You should concentrate on finding sources (preferably reliably published book sources) that support your contributions rather than arguing with other editors. Sources are key to building Wikipedia. Once we have sources, then we can talk about how the material in those sources should be presented. Without sources, you are likely to continue to be reverted. SpinningSpark 09:57, 9 April 2022 (UTC)
Here is a source for derivation of \Gamma_{SLIM} : It just is a bit more lengthy and thus not quite as straight forward simple as the one I presented, but it is excellent:
Orfanidis Sophocles J. (2016), ECE department, Rutgers University. "Electromagnetic Waves and Antennas", Chapter 16.4, Antenna equivalent Circuits, Page 749 and 750, derivating equations 16.4.4 and 16.4.7
URL = https://www.ece.rutgers.edu/~orfanidi/ewa/ch16.pdf - however, at this very moment it was not reachable: "proxy error" came. In case that stays so and you have an email, I can send it to you.
Does that make you happy?
I didn't doubt the math background, I asked for it. Thanks for finally answering that now. Why? As I think that a reader as well as a writer of a subject like that should have the backgrond adequate to the subject.
It is a nice theoretical objective, that everybody should be able to follow, even with no math background. But this matter (Impedance Matching) is no suitable stuff for a no-math person to start with.
Also the other equations used in the article don't comply with that nice theoretical objective. So why deleting my derivation, on the grounds that no math background readers should understanmd it at their first reading. That really is asking too much, and thus no deletion excuse.
Orphanides' derivation was a lecture at Rutgers University. If the derivation I presented truely was "not well understandable", this alternative probaly may be a little bit more demanding or lerngthy - but not a bit less quality. My approach is shorter and should be understood by age 15 pupils (I don't know what grade that represents in other countries). Orphanides' derivation, (chapter 16 out of 25), seems to be directed to an already advanced audience. This is why I presented, what I thought, was easier to understand. But obviously some of the math trained editors had a hard time (or pretencded to have a hard time) to understand it and used this as a deletion excuse.
Don't misunderstand it: I fully agree, that things should be presented as easily digestable as possible. But this subject means, the reader should at least have a basic understanding of what a complex impedance is. That certainly is not "no match background" and thus no deletion excuse.
Should you have an easier to follow derivation, that's great. Go ahed.
But no derivation, no \Gamma at all in the subject "Impedance Matching" is definitely subadequate to the subject.
So: Why not use the one I gave until a better one was found.
As you dind't answer with respect of the (little) flaw statement, you obvously understood and agree, that this sentence needs to be more precise. Obviously it existed since 2018, but nobody complained yet.
This, too, seems to describe the editor and the audience a bit. We all make mistakes. So there should be room for improvement.
Improvement is no bad thing. But deleting is a backward improvement - unless the deleted stuff was inadequate or wrong.
Stressing the need for verifyable RC and \Gamma{SLIM} equations, and explaining the difference (this is what the derivations do better than all comments) is certainly not asking to much.
In a nutshell: Don't delete a correct one, before you have a better one.
Should there be an error included. Please, please, tell me. That might be a genuine excuse for deletion - but not before first asking to fix the problem. 2001:16B8:2D3C:9900:D14C:16D5:5ED5:CC38 (talk) 14:49, 9 April 2022 (UTC)
You say "Improvement is no bad thing", but violating WP:TEXTBOOK is untenable. Binksternet (talk) 15:12, 9 April 2022 (UTC)
According to gbooks, the Orfanidis work is self-published, so not the best of sources, but we can probably accept it as Orfanidis is reliably published elsewhere. The work is available on IA, but chapter 16.4 is about "Half-wave dipoles" and pages 749–750 are about "Gain and Beamwidth of Reflector Antennas". Neither section mentions or reflection coefficient, so it goes no way towards verifying your work.
If you want to communicate by email, you need to be logged in. In fact, it would be beneficial generally if you stayed logged in while taking part talk page discussions. I would also advise you to keep your posts here shorter and to the point. Wikipedia:Too long; didn't read means the longer your post, the less of it gets read. SpinningSpark 16:52, 9 April 2022 (UTC)
DJ7BA (talk) 13:36, 10 April 2022 (UTC)Sorry for unintentionally not having been logged in. My fault.
Sory for my misspelling of Orfanidis, too. Chapter 16.4, "Antenna equivalent circuits" in my pdf copy at least, starting on page 749, includes equations 16.4.4 on page 750 and 16.4.7 on page 751 (sorry for any confusion, as I first had not seen the double page count per side by side screen page. So I said page 750 instead of 751). But maybe, Orfanidi edited things. My 16.4.4 and 16.4.7 equations are his derivation results of as he called it - \Gamma{gen} and \Gamma{load} - depending on transmit or recieve directions, having different generator and load sides. Thes \Gamma derivations are Source Load Impedance Mismatch \Gamma, not reflection coefficient type Gamma.
At this moment I have checked the URL. It is working now and the page numbers and equation numbers are there as now correctly shown above and correct enough to not having been lead to "Gain and Beamwidth of Reflector Antennas". I remember this page unaltered since mid 2019, when I downloaded my copy. So maybe, you have some older edition? But readers will find the new one.
\Gamma Index SLIM in \Gamma_{SLIM}, together with the full name in my context, "Source Load Impedance Mismatch" is fully self-explanatory and thus needs no "reliable source".
However it does deserve it's unambigous own name. "Reflection Coefficient" would be false, though for that error many thought to bei reliable sources can be quoted. So making clear, what is meant, is a must.
Finally I want to thank you for helpng me get better in understanding wiki style. Have patience with me, I'm newcomer, but improving. DJ7BA (talk) 13:36, 10 April 2022 (UTC)
Orfanidis starts with a well-known expression for total power delivered to the antenna. That is a valid starting point for a derivation. He then manipulates the expression to elimination the Re{} operator. That is a good start, but he stops there. There is no further derivation. He simply states that “the load impedance must satisfy the usual conjugate matching condition,” without any derivation and then defines . The source may be accepted as reliable, but it is not a source to justify your derivation. It also does not justify any statement about other sources being wrong. Constant314 (talk) 15:33, 10 April 2022 (UTC)
If we do use anything from the Orfanidis document, I suggest we don't cite to the version on the university website. These are notorious for linkrot. They only remain up for as long as they are useful to the university course they relate to. The version on IA is much more likely to be stable and has the same information in ch. 15 (not ch. 16). Or else, be sure to archive it in Wayback Machine to protect against linkrot. SpinningSpark 16:27, 10 April 2022 (UTC)
DJ7BA (talk) 20:50, 10 April 2022 (UTC)
"He then manipulates the expression to elimination the Re{} operator. " ???
Please explain: Please quote verbally the assumed "manupulation" line. It seems to me you are somehow using a different text version, so we cannot agree.
My version is the actuual - just compared - version that my URL mentions. You may have anything else, whatever.. That would be meaningless, as it is not my reference.
If, however, you see a "manipulation" in the same text that I use, please explain more precisely.
"There is no further derivation. He simply states that “the load impedance must satisfy the usual conjugate matching condition,” without any derivation"
He didn't write for wiki, else he could have shown a wikilink to "Maximum power transfer theorem", just as I did. What's wrong with that? Conjugate match is explained there. Isn't that enough?
Why re-event the wheel? Why making things unnecessarily lengthy and less digestable that way?
To my knowledge, the maximum power transfer theorem is generally considered as acceptable and needs no rederivation or explanation. The "Impedance Match" wiki article already uses it anyway.
The MPTT wiki also uses Orfanidis as source, but Chapter 13.1 in this case: "Conjugate and reflectionless matching". There Orfanidis promised to do derivation in Chapter 16. But both belong together.
If by any reason that is not digestable enough: Why not - more easily - use my shorter version, that is based on the same principles. It juxst uses current instead of power, as that means less derivation space.
But, as power is proportional by squared current, it is logically exactly the same thing. Just shorter.
Also Orfanidis uses - implicitely - the same "relative difference" approach - though using power, me using currents - in the central part of 16.4.4.
"relative difference" derivations can be done using actual and optimum currents, voltages or powers. I have done all three by relative difference approach, but currents is the shortest, best digestable one.
The only problem for digestability is: Many readers were mislead by the common thought that the reflection coefficient and the source load impedance misnmatch coefficient are the same. And they have the derivation of the RC in mind. That means, they expect some sort of incident and reflected wave etc. Yet there is absolutely no reflection in the source load impedance mismatch case. Even the RC can be derived without "reflected current". It is enough to know that somehow actual current in the load is less then optimum, be it because or reflecion, or be it because of not making full use of what is the maximum available power (like a high power car engine driving at moderate speed: No reflection, just not exploiting the available maximum.) For the "relative difference" approach in general it does not make any difference. What, however is different, is the goals and consequently the question, if impedances should be identical or conjugate for optimum match - meaning different optimum current.
The "relative difference" way of describing the coefficients is not narrowed down to reflections. Reflection thoughts may clutter minds. This could also be your hinderance in following my derivation. But a not so biased reader will find it quite easy to follow. Naming, what it is, "relative difference" may sound unusual, but It's really nothing new as it is implicitly used in all such derivations. I think, wiki will like the short and concise way. Especially, as the not experienced reader will find it easy to follow, and as wiki addresses these. Teenage pupils will be enough qualified to understand. Biased reflection current thinkers will find it harder.
I think, wiki should not warry too much about existing mindcluttering misconceptions, however, other than mentioning false examples like ATIS glossary RC definition equating both mismatches. The direct more digestable approach is far better. But experienced readers may be predetermined in their mind. Is that perhaps so with you? If so: No shame on you, Others had that mind cluttering hinderance before you already.
All ok now? DJ7BA (talk) 20:50, 10 April 2022 (UTC)
No. Since your source did not offer the same derivation, you do not have a reliable source for your derivation. You have no reliable source for your definition of gamma. WP:NOTTEXTBOOK still applies. Constant314 (talk) 23:54, 10 April 2022 (UTC)
I looked up WP:NOTTEXTBOOK and found:
This is exactly what the example used does: "inform rather than to instruct".
Another Orfanidis chapter was already used and accepted as citation source before I ever wrote anything for wiki. My quotation is not a bit less authoritative than the other.
I cannot help you, if you perhaps still use your obviously outdated Orfanidis version, you seemed to quote from before: I have no access to that. So why not use what everybody can clickt to.
also it was objected, that there was "manipulation" in it, but no quotation was given. This can be understood as unsubstantiated comment or even misunderstood as public author insult, that we certainly don't permit.
The citation that I used is an "example", not a literal copy and paste quote. The contents is unmistakably clear, Indices in Orfanidis' chaper 16.4 derivation were never meant to influence possible wiki reverters, but were used to fit his own example, that included a split of the antenna feed point resistance's real part into radiated and dissipated portions, unnecessaryly sidetracking from basic wiki knowledge to be presented here.
The use of "Source Load Impedance Mismatch Coefficient \Gamma_{SLIM} is self-explanatory to any reader interested in "Impedance Matching". It is needed for disambiguation. How else would you better name it? Please suggest. That will be appreciated as your positive cooperation on that. Thank you. DJ7BA (talk) 09:23, 12 April 2022 (UTC)

I will have limited or no availability for the next couple of weeks. Please do not take that to mean anything other than life intrudes on collaboration. Constant314 (talk) 17:14, 10 April 2022 (UTC)

DJ7BA (talk) 07:34, 12 April 2022 (UTC) The last revert by Binksternet is ridiculous. The Meaning of the Index of \Gamma is clearly shown in the context. This is not an "Invention", but an unavoidably necessary disambiguation. Disambiguation is the purpose of Indexing. The deleting also reverted to the already proven error "A conjugate match is different from a reflection-less match when either the source or load has a reactive component." This is not true: For the delete before read reverter again: Let RS Z_S = 100 + j 0 \Omega and Z_L = 50 + j 200 \Omega. This is a case, where either, but not both, have a reactive component. The Source is real only. Yet, in both cases the same result is: The coefficient is 0.52 + j 0.64 . True. So the false statement needed fixing. The false statement could have been uncovered immediatly, if the Source Load Impedance Mismatch Coefficient would have been used for calculation. This is nothing new, as the Orfanidis citation shows. Yet using an index is needed for people like Binksternet, so they can understand a proof by calculation instead of deleting. Deleting is not an academic approach, but, when notoriously repeated, might be seen as vandalism. This user Binksternet seems to already have a vandalism warning record on another wiki subject. Instead of continuing that path: Please give your reason, why a disambiguation of the Reflection coefficient RC and the Source Load Impedance Mismatch Coefficient \Gamma_{SLIM} may appear avoidable or wrong. How would you distinct the two different coefficients, please? That answer would be appreciated. Nobody so far has proven that both are the same. If you think you can, go ahead and try it. Deletion of the difference of the coefficients given, however, covers up the proof that the statment indeed was false. And, last, not least: The article subject "Impedance matching" without these coefficients would miss the possibility to evaluate the amount of mismatch, so very vital in impedance matching. In a nutshell: Don't again throw the baby out with the bath water, please. — Preceding unsigned comment added by DJ7BA (talkcontribs) 07:32, 12 April 2022 (UTC)

Edit warring on the article and making personal attacks on the talk page will not keep your preferred content in the article. MrOllie (talk) 12:59, 12 April 2022 (UTC)
All the established sources say "impedance mismatch", NOT "source load impedance mismatch". The problem is especially big If You Capitalize The Term and then supply the entirely new abbreviation SLIM. Binksternet (talk) 14:22, 12 April 2022 (UTC)
Thank you for suggesting, That's much better, as it indicates cooperation now instead of rude deleting. I really appreciate that.
The equation means for one of the two impedances, the source impedance, a kind of impedance, that a Thévenin equivalent source impedance may have. (The other impedance, the Load Impedance, is undisputedly the same in both cases.)
It is necessary to exclude from source impedance the often ambigously confused characteristic line inmpedance of a transmission line, that needs another coefficient, the reflection coefficient RC, instead. Somehow indicating that this is not the same, is necessary, as RC does not comply with the equation.
Using "Impedance mismatch" would be an excellent description, as it correctly tells, what the equation does: It yields, how much mismatch results from the difference between two ("genuine" or what is a better name?) impedances.
It is general practice to avoid ambiguity by indexing. The immediate context tells, what is meant. That indexing general practice needs no source for support, just as saying "Paris is the capital of France" (example that wiki uses) needs no source support.
Not using indexing, unfortunately would have supported the existing misconceptions that both are same. That misconception is so widespread that it even is part of standardising institution's glossary: IEC and ATIS. That reminds me somehow of the "PI act".
To me it looks like overly used wiki formalism suppresses disambiguation.
What shall we do then? Is there really a need to omit the totally selfexplanatory disambiguation by proper indexing?
Can you - having read this - now accept the indexing?
Or do you have a solution to the problem, that avoids such indexing? DJ7BA (talk) 07:36, 13 April 2022 (UTC)
It looks like you are trying to fix the problems introduced by IEC and ATIS and others, problems with ambiguity. But Wikipedia does not exist to correct ambiguities in the source. Such ambiguities should instead be relayed to the reader. Binksternet (talk) 12:36, 13 April 2022 (UTC)
Wiki "Impedance Matching" shows alread in the very beginning the two optimum case equations for "maximum power transfer" and "minimum Reflection".
It does currently not show what happens, when one or the other type mismatch occurs and how much infuence such mismatch means in comparative figures.
All I want to contribute, is two correct coefficients describing for both goals the figures, that result, if mismatch occurs instead of match. This must be supported. My shortest form given last is acceptable, but my easier to follow oneliners would be preferred.
I don't need to refer to ATIS or IEC at all. This is just for satisfying wiki's source hunger: We can easily omit that reference, if that is what garantees wiki-rule compliance.
On the other hand, it demonstrates the need to improve the page by adding the coefficients and by explaining, what they actually stand for:
Relative difference between an actual and an optimum value (using currents is easiest, but voltage or power could be used as well) for a specifeid goal. Relative difference must be wikilinked, as many don't know that term from school, even though it is generally omnipresent, i.e. when describing tolerances. Only that people are more used to percentages than to factors. DJ7BA (talk) 14:05, 13 April 2022 (UTC)

2001:16B8:2D86:CF00:59B5:8DD9:B7B2:67CD (talk) 18:33, 14 April 2022 (UTC)

For example: Besides Orfanidis, Kurokawa also can be used as second source: K. Kurokawa, "Power Waves and the Scattering Matrix," in IEEE Transactions on Microwave Theory and Techniques, vol. 13, no. 2, pp. 194-202, March 1965, doi: 10.1109/TMTT.1965.1125964. He uses the (though not expressis verbis called, what is common in math terminology, but not in everyday-language) relative difference between the source's optimum, that is, between the available power and actual real power in the load. In his derivation, equations (2) ... (13). What is imho better called \Gamma_{SLIM}, he calls "s" and derivates s = \frac {Z_L - {Z_i}^*} {Z_L + Z_i} = \frac {R_L + j(X_L + X_i) - R_i} {R_L + j(X_L + X_i) + R_i} (12) and (13). He then suggests: "Let's call it the power wave reflection coefficient". That nomenclature could ambiguously mean, waves are a prerequisite, but they are not. Some equations he uses in the beginning, and builds on afterwards, are general and not limited to waves. In his circuit 1 - the same type of circuit wiki uses - in absence of waves there are no reflections possible. Kurokawa, however, continues addressing readers of his earlier papers that included waves. That does of course not mean in any sense, waves are a prerequisite. So why use a misleading term, already known to have made readers insecure, if that is valid for waves only. We don't have to copy and paste a known weakness of a term into wiki, instead of clearly indicating what is meant by index and immediate index explanation in context. Further, we don't have to use his not selfexplanatory, never else found "s", that only makes any sense, if you just read the lines before in the article. So let's better call it "Source Load Impedance Mismatch Coefficient \Gamma_{SLIM}" - or, if you so will, "source load impedance mismatch coefficient \Gamma_{slim}"

"Relative difference" must be wikilinked, as many don't know that term from school, even though it is generally omnipresent, i.e. when describing deviation from a (what is still another reference than the goals needed here) nominal value. Only that people are more used to percentages than to factors in that case.

One more thing: It is correct in both, Orfanidis and Kurokawa sources, as well as in the "transmission lines" wiki section, to show the (in case of reflection coefficient) minus and plus signs that depend on direction - or on whether R_S \ge R_L or vice versa. In my shortened version, for the sake of being brief, that is omitted. In the one before it was circumvened by the very commonly used magnitude signes, that are appropriate to real power comparison. We could include these direction signs, that in power comparison are squared away anyway. \Gamma{SLIM} is useful for power maximizing. Signs are meaningless there. The lengthy sign discussion by Kurokawa appeared somewhat redundant to me. Also Orfanidis' both directions derivation falls into that category a bit. But they are correct and needed in a scientific paper with WP:NOR, but not necessarily in wiki.

To limit the explanation to "relative difference between an actual value and an optimum value for a specified goal" is the best KISS (keep it short and simpel) approach I know of. Why not make use of that it. Wikilink for relative difference shows that there are two solutions and using magnitudes is common.

Orfanidis and Kurokawa both used power comparison. I used current comparison. It gives a positive first solution, while voltage comparison gives a negative first solution - depending on R_S \ge R_L or vice versa, too.

In any event, using "relative difference between an actual value and an optimum value for a specified goal" is best putting in a nutshell, what \Gamma in general means. We must specify the goal. Relative difference and goal specification is implicit in each and every derivation I am aware of. Calling \Gamma a relative difference definitely is as little WP:NOR, as calling "1 + 1" a sum. So be not surprised, if so far unnoticedly you used it implicitely yourself.


2001:16B8:2D86:CF00:59B5:8DD9:B7B2:67CD (talk) 18:33, 14 April 2022 (UTC) Here is just another citation for the mismatch coefficient describing the relative difference between actual and optimum value (power) with respect to the goal of optimum conjugate, match:

Warren L. Stutzmann, Gary A.Thiele, „Antenna Theory and Design”, pages 102 and 112, equations 4-7 ... 4-9 and 4.39 ... 4-42. He uses relative difference in 4-41 and derivates from it what he just calls ambigously \Gamma - but understandable from context. The derivation exactly describes what I for the sake of unambigous clearness called "souce load impedance mismatch coefficient \Gamma_{SLIM}".

In a wiki article that mentions both mismatch types, power transfer maximizing as one goal, and reflection suppression as different goal, disunambigouation is a must. So indexing is unavoidable. Indexing should be as clearly understandable as possible. But it does not have to be the index, other pertinent sources used in their respective different texts. Stutzman, speaking about weak signal from the source sattelite reception antenna, has "r" for reception in P_{rm} that others don't need. What he means, is the actual reception direction real power. The optimum available reception direction real power he calls P_{rm,matched}.

We have three independant sources, all using different nomenclature and indexing, clear from their respective context. Wiki needs an unambigous, well understandable nomenclature and Index correctly, intuitively and unambigously desribing what is meant.

Does anyone have an index suggestion better understandable than "slim" in "source load impedance mismatch = \Gamma_{slim} ? I think, that is best. But alternatively "Real power transfer coefficient \Gamma_{rpt} or "Real power transfer coefficient \Gamma_{real-power-transfer} ? could be used. That is longer, but would also be a disambigouation from \Gamma = RC. Just \Gamma without index is unacceptably ambigous in this two matching goal type wiki article.

Any page improvement comments will be appreciated. DJ7BA (talk) 14:05, 13 April 2022 (UTC)

We have a concept called synthesis on our original research policy, which refers to combining sources together to make points that none of the sources make individually. That is forbidden by the policy. That looks like what you are engaging in here. It is not up to us to come up with our own nomenclature, we're supposed to follow a source. MrOllie (talk) 18:43, 14 April 2022 (UTC)
Thank you, MrOllie, for the info. It appears, that you are well informed about detailed interpretation of that rule. So excuse a learning wiki newcomer's questions:
Q:
Is that just a formal only, strictly legalistic interpretation possibility? Or is it a mandatory policy with no alternative what so ever, even if that means wiki edorses and enforces continued \Gamma ambiguity?
Is it perhaps some authority's discretionary decision - or is it your's?
If you are sure it is a strict mandatory rule without exception, be it ever so reasonable, I might find a possibility to suggest improvement to wiki for such matter. Who would be the person in charge?
Q:
Can I say: "The coefficient in case of source load impedance mismatch"? If not: What would be as good or better and wiki compliant way of indicating what the equation means (and what not)? Please suggest.
Q:
Is it also - because of (maybe) mandatory legalistic intepretation for each and every term's index - referring to a single source, necessary to say:
"The coefficient in case of source load impedance mismatch is: \Gamma = \frac {Z_L - {Z_A}^*} { Z_L + Z_A} (Source: Warren L. Stutzmann, Gary A.Thiele, „Antenna Theory and Design”, page 112)
instead of, referring to the existing wiki circuit's context,
"The coefficient in case of source load impedance mismatch is: \Gamma = \frac {Z_L - {Z_S}^*} { Z_L + Z_S} (Source: Warren L. Stutzmann, Gary A.Thiele, „Antenna Theory and Design”, page 112) ?
Synthesis of different origial sources:
Thanks for help DJ7BA (talk) 12:48, 15 April 2022 (UTC)
WP:NOR is one of Wikipedia's core policies. Everyone who edits here must comply with it on all articles. It is not a formality. - MrOllie (talk) 13:00, 15 April 2022 (UTC)
So: is it ok to refer to Z_S of the existing circuit diagram of the wiki article - instead of Z_A of a source using a very similar one, but naming it Z_A there?
I see it as no research at all, just using my own words for avoiding unnecessary obscuring.
Is that acceptable or not?
Is it wiki-compliant to just generally mention a "widespread misconception" without citing sources in this case in order not to expose these sources? DJ7BA (talk) 15:13, 15 April 2022 (UTC)
Absolutely not wiki compliant to mention a widespread misconception without the misconception being discussed in reliable mainstream sources. Using your own wording could possibly be allowed but not the way you have been doing it here, where you glorify your own wording with capital letters and the abbreviation SLIM. Binksternet (talk) 16:23, 15 April 2022 (UTC)

I am pretty sure that there is no widespread misconception. ATIS and IEC are both reporting correctly. There are communities that used those terms with those definitions. It is meaningful to them. Many, many technical terms are context dependent. These terms can mean different things to different people. There is no misconception to correct. Constant314 (talk) 21:36, 15 April 2022 (UTC)

Emphasis:
I din't intend to "glorify my own wording", I just didn't know better. I am still a wiki newcomer, but now I am beyond that point and will no longer call it \Gamma{SLIM}, as this (though appropriate) disambiguation is not used by sources that I could find, and I had to learn, that in such case it is considered WP:NOR. Thanks for the info. That unfortunately means, however: Wiki is more after quoting then after disambiguation. From my point of view, that is a wiki weakness.
To Constant314 and SpinningSpark: ( Constant314 uses bold italics in part of his his name, SpinningSpark uses red color in part, and bold in all of his wiki name) . I was told by Binksternet and SpinningSpark not to use such emphasis in text, as that would "glorigfy my own wording" when I used bold and italics for disambiguation. Accepted. May I kindly forward that to your attention - as you use it in your own wiki name, though not in text for disambiguation. It is wiki policy to assume goodwill. But what is that in your own name? You may come to conclusions yourself. For my part I assume goodwill: It allows you to faster find what you are looking for. Others like Binksternet (thank you for your kind note on that) might, however, perhaps be declined to think of self-glorification.
Proof of Reliability:
When it comes to publish what is true, correct math is absolute 100% support of factual trueth. Quoting ambigious or even false sources is dangerous with respect to trueth and understandability.
Quoting false things, and be the sources ever so well known or prominent, makes false statements not mysteriously become true. They are still false.
When, however, it comes to different opinions about facts, then reliable sources have their adequate place.
Science can be seen as a two storey house: On the first floor there are the facts. On the second floor there are theories explaining the facts. The first floor is proven trueth. The second floor is development of theories. These can differ and contradict. That's why they are just theories until proven or at least so generallyy accepted that no disproof appears to be adequately possible. In that case the theory can be used as if it was proven fact, but must still be called theory.
Disambiguation of two different Impedance Mismatch Coefficients:
There is impedance mismatch because of a.) reflection on a line, caused by difference between load impedance and a characteristic line impedance (if a line exists), and b.) because of other than conjugate complex source and load impedances. These are not the same, as the article correctly sais, when it talks about the two ideal cases: Isdentical impedance match for reflectionless matching, and conjugate impedance match or maximum real power transfer.
As both coefficients refer to their respective different ideal case as shown on wiki, the corresponding mismatch coefficients, both also referring to their respective ideal case, are different, too.
The proof is undoubtedly clear and was given before rbeing reverted: They are not generally the same - no matter what faklse infornmation or opinion people may have. Facts are proof, opinions are not.
Reply to: "I am pretty sure that there is no widespread misconception. ATIS and IEC are both reporting correctly."
The ATIS glossary statement: is found here: https://glossary.atis.org/glossary/reflection-coefficient-rc/
It is generally false to equate the reflection coefficient with source load impedance mismatch coefficient - except in a special case where source impedance or the characteristic line impedance is real only.
Characteristic line impedance may be considered to have little loss and thus to be (approximately) real only. That's good enough for many applications.
Using the reflection cefficient instead of the (source load-) impedance mismatch coefficient, that contrary to lines, can have have any arbitrary impedances, is false. No acceptable, approximate results are garanteed, but extremely false results can occur.
ATIS sais - and I quote from equation and text: "RC = \frac {Z_1 - Z_2} {Z_1 + Z_2}" ... "where Z1 is the impedance toward the source, Z 2 is the impedance toward the load"
While the equation describes the reflection coefficient, the text in note 2 describes the (source-load) impedance mismatch coefficient. That is - excuse me - false.
The correct equation for the text of note 2 is: \Gamma_{call it as you prefer} = \frac {Z1 - {Z_2}^*} {Z1 + Z2}, and the nomenclature must be explained correctly: "where Z_1 is the impedance toward the load, Z_2 is the impedance toward the source, the asterisc * meaning conjugate complex". (I don't mean Z_1 or Z_2 nomenclature, as magnitude bars are used, and also as there are two possible solutions, depending if real part R_1 \ge R_2 or vice versa. False isjust the missing * conjugate complex )
This was proven (as I did) by derivation. Meanwhile I found 3 derivations in sources, confirming that fact, too:
Warren L. Stutzmann, Gary A.Thiele, „Antenna Theory and Design”, page 102 and 112,
Orfanidis, Sophocles J (2016). "Electromagnetic Waves and Antennas - Chapter 16, pages 750 and 751, Equations 16.4.4 and 16.4.7" (PDF). ECE Department, Rutgers University. 2016,
K. Kurokawa, "Power Waves and the Scattering Matrix," in IEEE Transactions on Microwave Theory and Techniques, vol. 13, no. 2, pp. 194-202, March 1965, doi: 10.1109/TMTT.1965.1125964.
I challenge you: Try to prove the ATIS glossary statement to be correct by correct math derivation: You cannot.
The IEC glossary statement, that implicitely uses \Gamma in the Return loss quotation, is found here: https://www.electropedia.org/iev/iev.nsf/display?openform&ievref=702-07-25
It sais, and I quote from equation and text: " -20 lg |r| = 20 lg \left | \frac {Z - Z'} {Z + Z'} \right |"... "where Z is the characteristic impedance of a transmission line ahead of a discontinuity, or the impedance of a source, and Z′ is the impedance after the discontinuity or the load impedance seen from the junction between the source and the load."
false is
a.) the '-' minus sign on the right side of the '=' was forgotten (without respective change of denominator and numerator)
b.) "impedance of a transmission line ahead of a discontinuity, or the impedance of a source" again is equating falsely, just as explained above referring to ATIS glossary,
While a.) may be easily considered a typo, that watchful readers can find, b.) is false and misleading.
In both cases: Quoting so-called "reliable" sources is not the solution, as there are examples from prominent sources that are considered to usually be reliable. But nevertheless they copied that flaw:
Just as Trevor S. Bird, former IEEE chief editor, in https://www.qsl.net/ve2pid/ReturnLossTrevor.pdf .
His article has just one point: Return loss in a passive lumped element circuit cannot be negative. He sais, some 30% of editors submitting articles including return loss, use it falsely.
This demonstrates the "value" of using a source without checking it by math: Trevor s. Bird himself uses as definition on page 2, center to lower half, - and I quote from equation and text:
" (C) More broadly, the return loss is a measure of the dissimilarity between two impedances, being equal to the number of decibels that corresponds to the scalar value of the reciprocal of the reflection coefficient, and hence being expressed by the following formula: 20 log_10 \left | \frac {Z_1 + Z_2}{Z_1 - Z_2} \right | "
This is better than IEC above, except "More broadly the return loss is a measure of the dissimilarity between two impedances". This is ambigously making no difference between a characteristic line impedance and a source impedance.
Thus it means equating both and consequently equating the reflection coefficient with source-load impedance mismatch coefficient.
I emailed corresponded with Trevor Bird. He admitted, that it looks that I am right - but he didn't have the time to detail check that.
The remarkable thing is: He 100% stresses that return loss in a lumped element passive circuit must be positive, yet provides a definition, that, if entering some complex impedances, yields negative return loss, contrary to his paper's most important point.
I am not a bit questioning his great ability. I just want to unviel the hidden error.
Wiki permits to use this article as reliable source in other places. I fully endorse using it. It has so much good and important info in it. It would be a shame to throw the baby out with the bath water and to no longer quote that precious source.
However, wiki should permit to mention the error that was found and have it corrected uin a wiki article, rather that endorse a proven to be false false statement by quoting without comment "as that would be WP:NOR".
I don't criticise wiki's rules other than if they prevent proving trueth while at the same time promoting false info. That's not fair to the readers.
I don't want to be part in a wiki system, that promotes spreading what is known and proven to be false - but at the same time doesn't permit proving what is correct.
As I said before: using "2+2 = 4" is using trueth. Quoting ever so well-known people like Trump or Putin certainly is no garantee for trueth. DJ7BA (talk) 11:57, 16 April 2022 (UTC)
Bringing up 'truth' like this is so common among new editors that we have a prewritten answer to it, which you can find at Wikipedia:Verifiability, not truth. - MrOllie (talk) 12:41, 16 April 2022 (UTC)
Thanks, MrOllie. I will look it up.
My other reply contents is important, however, too.
I still call "I am pretty sure that there is no widespread misconception. ATIS and IEC are both reporting correctly." precipitated opinion. There may be controversial opinions, but factual trueth is found by proof only. DJ7BA (talk) 13:15, 16 April 2022 (UTC)
And the factual truth is reported by us when it appears in reliable sources. We don't do the proving ourselves. Either accept that is how things are done here and drop the stick or else go and write on some other website. SpinningSpark 13:36, 16 April 2022 (UTC)
I accept that verifyiability of a source is needed. I also accept that different opinions are allowed - of course.
What I cannot accept, is: Reverting my derivation that was nothing but present 100% verifyability.
There was hoever, maybe, a multiple cause, cluttering my interpretation: as I had more than one wiki objections, like also using SLIM as index for \Gamma, too. Because of the (multiple) full reverting, I was unable to see, what single cause made me think, perhaps that derivations igenerally are not allowed and the ereverting peolpe simply wanted to suppress any idea, that the widespread misconceptio is, what it is: A misconception.
Maybe, that conclusion wasn't true, or isn't any more, as meanwhile I provided references. These three all support the (source-load) mismatch coefficient equation derived by me.
I learn from that: I must only provide one little single page improvement contribution at a time. So only one single objection cause is possible and thus can be analyzed for improving my wiki editing abilities.
What I cannot accept - if that was no misunderstanding that can be cleared, is: Reverting again the coefficient responsible for source load mismatch on the fabricated cause, that MrOllie thinks: "I am pretty sure that there is no widespread misconception. ATIS and IEC are both reporting correctly." I may use just \Gamma without index label, if that is really necessary. But in math, it sais: "If two quantities (the two different coefficients) each are identical with a third quantity (\Gamma with reference to the very same circuit diagram), so the two are are identical themselves." This correct math principle would be infringed by using no index, no context. So some way must be permittet to not confuse the two different coefficients. What is that way?
If they were the same - as is easy to suggest by quoting mislead themselves sources like ATIS and IEC, there must be some way to express on the pertinent page, that there is widespread misconception.
If not: Why use wiki's known to be forced desinfo services at all?!
Please be helpful and show me the wiki compliant way to properly present the (source load) impedance mismatch coefficient.
There is no stick to be dropped, as one side was never permitted even once. DJ7BA (talk) 15:35, 16 April 2022 (UTC)
I didn't write that. Please read the discussion over again, including the links people are posting, as it seems you are not taking on what people are telling you. MrOllie (talk) 15:57, 16 April 2022 (UTC)
Your posts are far too long, much of it off-topic. The issue of usernames is way off topic – I will reply to you on that on your own talk page. I have long since given up reading all of what you write. It is just too hard trying to figure out what your central point is. You need to keep them more succint.
Is the central issue here that you want to define a "source-load impedance coefficient" as a corollary to "reflection coefficient"? We have already established that there is no such terminology in reliable sources. Please provide one source (at most, two) that directly define this coefficient by any name. I don't want ten sources from which you can stitch together what you want to say, just one that says it directly.
I have no idea what your problem is with the section on stepped transmission lines and note 2. Neither the section or the note talk about any kind of coefficient. The source paper only talks about reflection coefficient. Since the source and load are separated by multiple sections of transmission line, there is no direct source-load matching with this technique. SpinningSpark 13:52, 16 April 2022 (UTC)
One at a time:
"Note 2" in ATIS glossary for "reflection coefficient" on: "https://glossary.atis.org/glossary/reflection-coefficient-rc/" sais, and I quote: "where Z_1 is the impedance toward the source, Z_2 is the impedance toward the load."
It seems, that somehow source copying from wiki footnotes is yielding other things than what was written there, marked and copied into anothe place, perhaps. I am sure, I quoted nothing about stepped transmission lines.
That may, however, have been in a section of another (not ATIS) source. I have noticed such problems before, and this is why I quoted the text by retyping words and equations - what makes it longer. Sorry, but I don't know how to prevent, what might be a programming improvement need.
I now retype the URL that here sais: "https://glossary.atis.org/glossary/reflection-coefficient-rc". Ooh, it automatically creates a link again. Please, should you get a false link, enter in your browser, leaving out the blanks: h t t p s : / / g l o s s a r y . a t i s . o r g / r e f l e c t i o n - c o e f f i c i e n t - r c . That should get you to you the correct page I referred to. Or did I have a detremental typo in the URL perhaps. I don't know. Please excuse, if so. DJ7BA (talk) 16:04, 16 April 2022 (UTC)
Ooh no - bad URL again so sorry, looks as being my fault this time.
I hope I get it right now:
h t t p s / / g l o s s a r y . a t i s . o r g / g l o s s a r y / r e f l e c t i o n - c o e f f i c i e n t - r c
So sorry. DJ7BA (talk) 16:13, 16 April 2022 (UTC)
This conversation is not getting anywhere. ‎DJ7BA simply keeps repeating the same points without engaging the other editors’ comments. When DJ7BA’s issues are addressed individually, DJ7BA does not seem to read them or respond in a way that indicates understanding. I will make this suggestion: DJ7BA should kindly pick one and only one issue that they wish to discuss and start a new topic on the issue. We will discuss it until it is resolved. They we can start the next topic. Until DJ7BA complies with this simple request, I will withdraw from the discussion. I will, however, continue to revert any new material that is too broken to fix. Constant314 (talk) 04:44, 17 April 2022 (UTC)

DJ7BA (talk) 07:10, 17 April 2022 (UTC) Last I said: One at a time". This, at least, we can agree on. So go ahead, please answer just that one point:

Is ATIS glossary of reflection coefficient RC correct in note 2, that includes mismatching source and load impedances, instead of limiting RC to mismatching characteristic transmission line and load impedances?
If you can, please support your answer by proof.
I would appreciate your careful reading of: Wikipedia:Please do not bite the newcomers DJ7BA (talk) 07:09, 17 April 2022 (UTC)
This one is easy. Neither ATIS nor IEC control the meaning of the terms “reflection coefficient” and “return loss.” These may be reliable sources, but they are not authoritative sources. Both the ATIS and IEC documents function merely as dictionaries. That is, they catalog the way the terms are used. They are just tools you can use or ignore. A purchaser of telephone terminal equipment might specify “return loss of at least 33 dB as defined in IEC Pub xxx.”
In fact, there is no authority anywhere that controls the meanings of those terms. The terms mean what the people using the terms say they mean. It doesn’t matter if there is another community that uses the term “return loss” to mean something else. The only misconception is everybody has to use the same definition.
The definition of reflection coefficient in ATIS may be correct for some people and incorrect for others. The only oddity that I note is the ATIS uses the absolute value of the expression rather than the complex value. But that may be correct for the community that ATIS serves.
I took a closer look at ATIS Telecom Glossary. Note, it calls itself a telecom glossary, so you can expect that its definitions will be aimed at the telecom industry. In particular, it gives RC=| (Z₁ - Z₂) /(Z₁ + Z₂) |. Since it uses absolute value in the definition, it does not matter which impedance is the load and which is the source. Sometimes you need to use the complex value and sometimes you do not. Otherwise, it is correct.
But the phone company really uses return loss because they have a return loss test set that produces numbers in accordance with RL= 20 x Log₁₀ | (Z₁ + Z₂) /(Z₁ - Z₂) |. This is a sort of designer parameter. The telco technicians certainly were not expected to be able to compute complex arithmetic. When working with return loss in dB, bigger numbers are better. The telco tech is simply told something like, “the return loss on this circuit must exceed 20 dB.” It works for them.
The ATIS glossary gives with RL= 10 x Log₁₀ | (Z₁ + Z₂) /(Z₁ - Z₂) |. I think that is probably wrong by a factor of two, but maybe I am wrong. The IEC document defines it on a linear scale instead of a dB scale, but it is the same thing.
Anyway, it is not Wikipedia’s job to declare that ATIS is wrong. It is ATIS’s job to satisfy their customers. If you are a customer of ATIS and you think that they have the wrong definition, you have the right to complain to them. But here at Wikipedia, we are not giving you a platform to call them out. We do not right great wrongs or even minor wrongs. What we do is paraphrase reliable sources or copy reliable public domain sources. That is it. If you want to do something that is not entirely covered by those two possibilities, then it is not allowed.

Constant314 (talk) 09:02, 17 April 2022 (UTC)

DJ7BA (talk) 08:54, 18 April 2022 (UTC) replying to Constant314, 17 April 2022, 09:02:
Thank you for the info on the ATIS glossary definition of RC.
It confirms that you did not prove the validity of the ATIS glossary RC definition, equating reflection coefficient in note 2 with what actually is a source to load mismatch coefficient.
That still is an unproven assumption (respectfully avoiding the harsh term "false").
Concerning to the magnitude bars: You are right. RC is a complex coefficient. |RC| would be non-complex, but it sais "RC = | ... |."
concerning: "The ATIS glossary gives with RL= 10 x Log₁₀ | (Z₁ + Z₂) /(Z₁ - Z₂) |" I agree on factor two - (unless definition for powerdB is found in context. This version sometimes is in use, too.)

The point that you may have missed, is:

ATIS glossary note again sais in this (RL) place, as they already said in the (RC) place, too: ..."where Z1 is the impedance toward the source and Z2 is the impedance toward the load". This context note describes a source load mismatch coefficient, while the equation describes a reflection coefficient. The difference is the missing * to go with source impedance, but not with characteristic line impedance.

That false equating what is not equal, always was my point in everything I posted. Sorry, if I may not have expressed that clearly enough - perhaps because of too many too lengthy explanations. Sorry, that was not so nice. If so: My fault. — Preceding unsigned comment added by DJ7BA (talkcontribs) 14:55, 18 April 2022 (UTC)

Your main, very good, point, however, is:
By wiki's definition of reliability of a source, you confirm that such glossaries as ATIS and IEC, are no authoritative sources, just "maybe reliable" (for some readers, believing what they see from a different point of view or bias.)
According to wiki "reliable sources" definition,(3.1) they "rely heavily on rumors and personal opinions." and as dictionary, as you say, they just catalog the way, terms are used.
This type of source would be considered tertiary. I can fully accept this reasonable wiki reliability category. If there is any better reliable source concerning RC, this one's content will not be accepted as reliable.
If a wiki article would state: "There is a widespread assumption ... ", this could be used, maybe together with more similar sources, to support such statement (but not it's content).
OK, as I see it, that takes care of that point. Thank you.
What is your next - one at a time - question? I perhaps din't answer? DJ7BA (talk) 08:54, 18 April 2022 (UTC)
Note 2 says “ Return loss is a measure of the dissimilarity between impedances in metallic transmission lines and loads, or between refractive indices in dielectric media, e.g., optical fibers.” That is sufficiently vague to cover a lot of possibilities. There is no reason to infer that it means “a source load mismatch coefficient.” Since the entire expression is within the absolute value bars, it does not matter which impedance is the load and which is the source. In any case, the formula is correct except for a possible factor of 2.
I consulted ANSI which calls out IEEE Std 743-1995 (or later). The definition there is RL= 20 x Log₁₀ | (Z₁ + Z₂) /(Z₁ - Z₂) | where Z₁ is the impedance of the circuit under test and Z₂ is the reference impedance. The reference impedance is typically either 600 + 1.8μF or 900 + 1.8μF.
In my opinion, ATIS is wrong by a factor of 2, compared to ANSI. I am not sure that ATIS should be considered a reliable source. I would not use it. IEC is a reliable source, but only about the content of their publications. Likewise, ANSI is a reliable source about the content of their publications.
However, I am glad that we can now drop the discussion about ATIS and IEC. We do not care what they say unless someone is trying to use one of those as a reliable source. Constant314 (talk) 23:52, 18 April 2022 (UTC)
DJ7BA (talk) 08:15, 19 April 2022 (UTC)
You still have not accepted or else disproved the fact, that each of these notes
1.) Note 2 in ATIS glossary (RC) sais: "where Z1 is the impedance toward the source, Z 2 is the impedance toward the load" right next after the RC equation given in ATIS RC glossary,
2.) Note 2 in ATIS glossary (RL) sais: "where Z1 is the impedance toward the source and Z2 is the impedance toward the load" right next after the RL equation given in ATIS RL glossary,
exclusively describes a source load impedance mismatch situatuation, as Z1 is called "the impedance toward the source" - but not "the characteristic impedance of a transmission line".
In other words: These notes do not at all, also not "vaguely" describe reflection,.
But the title and the equation does describe reflection.
So title and equation on one hand, and the respective context note explaining Z1 on the other hand, are incompatible.
If you agree, this ATIS subject can be closed and we may proceed, if you like, to ANSI which calls out IEEE Std 743-1995 (or later) - a subject including new points such as numerical impedance figures etc.
If you don't agree, I suggest we limit discussion on ATIS (RC), as ATIS (RL) is directly based on ATIS (RC) and at this point ATIS (RL) unnecessarily may expand the discussion. DJ7BA (talk) 08:15, 19 April 2022 (UTC)
DJ7BA (talk) 12:00, 19 April 2022 (UTC)Correction: In ATIS (RL) - what I wanted to refer to - is not, what erraneously I called,"note 2". It rather there it is the context immediately following the equation. Sorry for my garbled citation, that mainly had ATIS (RC) in mind.
The essence, however, is exactly the same. Just the context location I was referring to, indeed is different. DJ7BA (talk) 12:00, 19 April 2022 (UTC)
Yes. I agree. Let's close the discussion of ATIS and IEC. I think the next subject to discuss might be reflection coefficient. We should start a new section for that. Constant314 (talk) 13:24, 19 April 2022 (UTC)
Great.
OK to start a new section for reflection coefficient. Do you mean here in talk - or on the "Impedance Matching" page?,
As you like. I have no objection with regard to the correctness of contents of the already existing RC derivation found so far under "Single-source transmission line driving a load" on "Impedance Matching".
A new section "Reflection Coefficient" can only describe reflection caused mismatch calculation - not source and load impedance difference caused mismatch calculation, that does not have any reflection - just a complex voltage divider circuit - but no medium for waves to be reflected. (If the source impedance is at a transmission line's load end, the Thévenin source impedance existing there is not identical with the line's characteristic impedance.)
There is, however, the possibility to describe both coefficients in a likewise manner. That way it will be easier to compare and to understand both. It will be presented like a brother and sister pair of twins, similar, but not identical - just nice.
No new research at all, just a nice way to present both mismatch calculations.
The new subject may have a header "Mismatch", "Mismatch calculation" or "Mismatch coefficients".
It may have suitable subheaders for Reflection Coefficient and Source Load Impedance Mismatch Coefficient. We might or should find better subtitles though.
Am I perhaps going ahead too fast? I don't want to skip any of your points.
Thanks DJ7BA (talk) 16:11, 19 April 2022 (UTC)
DJ7BA (talk) 16:13, 19 April 2022 (UTC)Oh, I submitted before scrolling down.

Reflection coefficient

The reflection coefficient (RC) is a widely used concept that appears in many reliable sources across many subject areas that involve waves. It applies to circuit quantities (voltage and current), electromagnetic quantities (E and B), sonic quantities (velocity and displacement). Typically, the symbol Γ is used for reflection coefficient, although ρ and r also appear in reliable sources.

In circuits, the voltage RC has the opposite sign to the current RC. When not specified, voltage RC is usually assumed.

In electromagnetics, the E-field RC has the opposite sign to the B-field RC. When not specified, E-field RC is usually assumed.

Here are some reliable sources that can be accessed from the internet.

  • Harrington, Time-Harmonic Electromagnetic Fields, p. 55, eq. 2-45 [1] for a wave propagating from media 1 to media 2. η is the wave impedance of the media.
  • Hayt, Engineering Electromagnetics, 8th ed, p. 321, eq. 73 [2]
  • Wadell, Transmission Line Design Handbook, p. 501, eq C.2 [3]
  • Steer, Microwave And Rf Design: Transmission Lines, p. 68, eq. 2.59 [4]
  • Rosenstark, Transmission Lines in Computer Engineering, p. 23, eq. 2.6 [5]

Harrington is a widely cited graduate level text book used in the study of wave guiding structures.

Hayt is a widely cited under-graduate level text book used in electrical engineer schools.

Is there something that should be added to this article about reflection coefficient? Constant314 (talk) 16:06, 19 April 2022 (UTC)

The only thing a could quickly see, is: The greek letter (how to render that on a talk page so nicely?) \rho is used for the magnitude of the reflection coefficient in my so far known sources. So that obviously is common.
For easier disambiguation, I would suggest to not use as source Wadell or Rosenstark - or alternatively - simply put it right, meaning using some other name than \rho or \rho_L,
or adding magnitude bars as deemed necessary perhaps. In that case there must be a note, why that was done, so nobody could accuse you for sloppy misquoting.
Except this: Excellent. I like it.
Q:
Is that meant to be part of the page "Impedance Matching" or as an alternative part in the page "Reflection Coefficient"? DJ7BA (talk) 16:28, 19 April 2022 (UTC)
This discussion is about this article. Reflection coefficient has come up several times in the discussions. I want to know if there is any content that you wish to add or change in this article about reflection coefficient. If you want to add or change content in the reflection coefficient article, it should be discussed on the talk page of that article, but please hold off until we are done discussing this article.
I see I did not answer the query about Greek letters in talk. If you directly edit the source, you get a menu at the top of the page that allows you to insert symbols. I also use MS Word to prepare comments off-line. I use the insert symbol tool in word and then copy and paste the text into Wikipedia. It usually works. Constant314 (talk) 16:37, 19 April 2022 (UTC)
Ok. understood.
No objections so far. Good explanation, good sources. No ambiguity, as if the reflection coefficient might include matters that are subject to source load impedance mismatch in some mysterious "broader", "more universal" or "vague" understanding of a certain "school of teaching". That's what I want to make sure, is avoided. I omit quoting those sources, who used these ambigous, general terms, as that is not nice and also is not necessary.
I have, however, not yet accessed the contents of your sources on the internet. That may take some time. DJ7BA (talk) 16:53, 19 April 2022 (UTC)
DJ7BA (talk) 15:33, 20 April 2022 (UTC)After a first reading of [2] ... [5] only, as [1] doesn't open without agreeing to ads, thus accepting commercial profit:
You can avoid the ads on #1 by clicking the blue download button on the left and then on the resulting page choose "download the full pdf" which is a white button. This is a very valuable addition to your collection especially if you are interested in waveguides. Constant314 (talk) 17:12, 20 April 2022 (UTC)
No objections with respect to contents. All are prime quality and reliability sources, deriving flawlessly.
More than that: My \Gamma = RC derivation is fully supported - see Wadell page 501, C4, C3 and C2.
Minor differences only - but no flaw:
  1. Indices. It seems, every publication uses it's indexing just as in it's context. No way to use theoretical only, common indexing. Rather, context tells what is meant. Imho an index should be "speaking", to tell, what is meant.
  2. Using voltage across vs. current through R_L. It yields negative signs, I postponed that, knowing it is magnituded away later with |\Gamma| in SWR anyway, together with: R_L \ge R_S or vice versa . But I could add and explain signs.
  3. Sequence of derivation lines: I had a oneliner, all connected by = symbols. From left to right I started with what is obvious, as given by the circuit and by the already existing equation given on top of the "Impedance Matching" page.
No logical difference, whatsoever. Not yielding a result, that was presumed.
Do you still see a problem in my \Gamma = RC derivation - if so, what is it?
Let me try to answer that myself: I see no need for doubling, and I don't want to erase someone's existing nice derivation using incident and reflected waves, that I took for granted. There is room for debate.
If we use it, then for the beauty of seeing the twin sister and brother pair of both mismatch coefficients derivated together, thus indicating so easily, what is the differnce: The goal for the respective optimum values.
That makes it easy to understand \Gamma. At the same time it helps readers to avoid ATIS/IEC glossary type confusion, equating wave reflection in a medium or line with a complex voltage divider without reflection.
One more comment:
What do you think? DJ7BA (talk) 15:33, 20 April 2022 (UTC)
First, I agree that you got the correct result. However, there are three problems with your derivation.
  • Wadell doesn’t give a derivation. He gives the result of the derivation. It is a reliable source for the result, but it is not a reliable source for the correctness of your derivation.
  • You define Γ as the relative difference between the actual current and the optimum current. That definition does not appear in any reliable source. It may be coincidentally correct, but it is an observation and not a definition. Γ is defined as the ratio of the reflected signal to the incident signal. Its purpose is to let you calculate the amplitude and phase of the reflection. Its purpose is not for calculating the relative difference between the actual current and the optimum current. No one cares about that. They care about the reflected signal.
  • You start with the knowledge of the optimum current, which is the current that you get when there is no reflection. But you don’t know that until you have derived it. You cannot start with that.
The usual approach is to assume that there are 2 coefficients, Γ and T, such that the reflected and transmitted signals are given by
then you apply the continuity requirements which are:
  • This is the voltage continuity requirement. In words: incident voltage + reflected voltage = transmitted voltage.
  • This is the current continuity requirement. In words: incident current - reflected current = transmitted current.
From that you derive and
which reduces to which can be manipulated into
This is essentially the derivation given in Hayt on page 321, except he doesn't bother with defining T. Constant314 (talk) 21:15, 20 April 2022 (UTC)
Call it "derivation" (what it actually is for just the part that I added), or not. Call it "calculation", if you will:
Using currents (knowing, I could have used voltages or powers just as well) further above I first showed that , is a most basic, unitless measure.
What I should have said at that place, is, what both coefficient types have in common:
" is the relative difference between the actual value of a quantity (i.e. current, voltage or, using square, power) and the optimum value for a specified goal."
I regret not having said this at that time and place. Sorry.
And: What they do not have in common: The RC only equation, that is limited to reflection, not applicable to a complex serial impedances circuit.
For RC, I used a circuit diagram, indicating the unmistakable meaning of the terms/indices in my equations.
Quoting Chipman, I used his "hypothetical infinite lenght transmission line" approach as wiki compliant, reliable source for the claim, that for best reflection suppression
the optimum goal, complete reflection suppression, is achieved with identical impedances. This is my presumption Nr. 1. It is on the page already. No need to derivate again.
My presumption Nr. 2 is Ohm's law applied in the circuit shown. No other presuptions.
The two currents are calculated:
1. From the circuit I showed, that .
2. Using the other presumption, Chipman's identic impedances for zero reflections on a line, I used from what is also already on the page,
the optimum case: and
With this I calculated the optimum case current .
Knowing actual and optimum currents, we have everything needed to calculate .
I cannot see anything wrong. There is still room for (minor) improvement: style (no bold), indices (no capitalizing), and the omitted explaining sentence, what both coefficients do have in common.
I would like to see both twin brother and sister (partial or incomplete, if you will) derivations (or calculations, if you will) close together, so that it is easy to see what actually is the difference:
Just the goal dependent optimum values for each case: Reflection suppresion vs. real power transfer maximizing.
Is that acceptable to you? DJ7BA (talk) 09:30, 21 April 2022 (UTC)
As I said, there is nothing wrong with your math. But your starting point is not notable. No reliable sources start with that. The reason Chipman could say what he did was because he or someone prior had derived the reflection coefficient. It is not notable or profound that you can use a result that depended on the reflection coefficient to derive the reflection coefficient.
The reflection coefficient is applicable to a complex series of transmission components. Starting at the terminal load, there is a simple recursive relation that lets you calculate the equivalent reflection coefficient seen by the source.


The flow of results goes like this:
Fundament physical requirements → reflection coef → optimum load → optimum current.
What you have done is this:
optimum load + optimum current + convenient definition of Gamma Gamma = reflection coef
All that you have shown is that the algebra at the tail end of derivation is reversable.
The only thing important and notable is the fundament physical requirements that start the entire deductive chain. Constant314 (talk) 12:21, 21 April 2022 (UTC)
Thank you
for stating, that nothing is wrong with my math. I was not sure, as you had said:
"You define ... That definition does not appear in any reliable source. It may be coincidentally correct, but it is an observation and not a definition."
But that is clear now:
What might be called "observation" only is my wording, that calls it a "relative difference". But that is fact and this fact also is wikilinked. And wiki permits one's own wording.
This fact is not just "may be" by some mysterious coincidence, but in full conformity with all sources you gave, and in no way, what so ever, contradicting them in any point. (Else prove it.)
There is one thing I didn't present for the sake of being brief: The same type calculation, but using voltages: Same result, except for the sign. This, too, is supported by your sources.
Also it is already generally supported by the wikilinked page on "relative difference and change", suggesting use of magnitude as deemed appropriate.
But you are right:
In essence you say, that the reliable sources you are aware of, all start out from scratch and in profound detail, meaning the "usual" way of comparing incident and reflected wave's voltage and current.
For profound RC basic derivation that is correct.
However:
This profound RC derivation later is found already on the page in section "Single-source transmission line driving a load". Right?
The conclusion of this is: We should carefully reconsider the structure of the page to achieve a nice logical presentation sequence.
The introduction (till ) can stay.
Then a story bridge:
Theory ideals and real world actual values differ. This is why suitable coefficients express mismatches by number, and with respect to their unequal goals.
My contribution may then follow the introduction as an overview, presenting the two coefficients, what they have in common and what not, as the equations show. In-page links should point to in-depth derivations given later.
As mentioned, one is shown in "Single-source transmission line driving a load".
Another link will point to a brief new section with reliable sources for what I call the "source load impedance mismatch" (how else would you perhaps call that?), giving whatever derivation is available.
I know, that section will be somewahat short in comparison, as there is no such whealth of material as for RC, but at least it is sufficient to wiki-reliably support the second coefficient, too.
We may want to go to some more degree of "from the scratch" by using (or deriving) the maximum available real power and compare it with the actual real power in the load resistance.
That is fair, as it all is about real power transfer, and thus the relative difference between actual and available (=optimum) real power is more basic than an approach that uses currents.
I also think, it is nevcessary to point out, that for the purpose of the coefficient, real power transfer, only the magnitude of the coefficient is meaningful.
Can we agree:
On a wiki page about "Impedance Matching", mismatch calculation with respect to both match ideals presented in the beginning, is a "must".
Without it, a page on that subject would be terribly incomplete. At present, this is so.
The good news is:
There is room for improvement.
Correct? DJ7BA (talk) 19:54, 21 April 2022 (UTC)
Sorry. The material simply is not notable. Your "story" does not appear in a reliable source. You are supposed to use your own words to paraphrase reliable sources. However, you have not paraphrased any reliable source. I get the feeling that you do not understand the meaning of paraphrase. It has a very narrow meaning that does not include telling a new story, making observations, or asserting new definitions. Constant314 (talk) 21:29, 25 April 2022 (UTC)
DJ7BA (talk) 12:01, 20 May 2022 (UTC)
But this is notable:
=== Derivation of Power Mismatch Coefficient ===
In the general case, source and load impedances don't have perfect conjugate match needed for full power transfer. Instead, both are mismatched. [1] ... [8]
Let be the maximum available small signal real power of a reception antenna with source impedance ,
and be the actually received real power in a directly connected LNB (low noise Block) with load impedance .
For a general load condition
For conjugate match this reduces to
The ratio of these is called impedance mismatch factor
By normalizing to unity, this quotient is a real number , expressing the actually received real power relative to the maximum available real power.
The relative difference between actually received and full available power, is the squared magnitude
with index for power.
Solving for yields
  • Warren L. Stutzman, Gary A. Thiele, Antenna Theory and Design, – 3rd ed.
ISBN 978-0-470-57664-9 (hardback) Antennas (Electronics) I. Thiele, Gary A.
ch. 4.2 Receiving Properties of Antennas,
p. 102, eq. (4.7) … (4.9) [6]
ch. 4.4.4 Impedance Mismatch,
p. 112, eq. (4-39), (4-41), (4-42)
[7] Voltage Reflection Coefficient
p. 750, eq. (7.4.4),
p. 751, eq. (7.4.7),
  • Lamin Zhan, Shihao Qi, Baoquan Hu, Yunzhong Wu, Changzhong Chen,
Reflection coefficient between complex impedances, Conference Paper · May 2020,
School of electronics and information, Huazhong University of science and technology
and/or Aviation Industry Shanfei Company, Hanzhong,
p. 3, eq. (11), reflection coefficient derived from the forward and reverse power waves
  • K. Kurokowa, Powe - {Z_S}^* } {Z_L +r Waves and the Scattering Matrix, 1964
https://cseweb.ucsd.edu/classes/fa12/cse291-c/papers/ScatteringMatrix.pdf
p.195 Fig. 1, p. 196, eq. (12) Power Wave Reflection Coefficient
p. 195 eq. (14) power reflection coefficient
  • Thomas R. Cuthbert Jr., Ph.D., Broadband Direct Coupled and Matching Networks,
https://archive.org/details/ost-engineering-rf_networks_ocr
p.9 eq. (2.1.3)
generalized reflection coefficient
p.9 eq. (2.1.4) with being the conjugate of the source impedance used as reference impedance in the Smith Chart Center, .
  • Shuhei Amakawa, Scattered reflections on scattered parameters, demystifying complex referenced S-Parameters,
IEICE TRANS. ELECTRON., VOL. E99-C, NO.10, OCTOBER 2016
p. 1103, ch. 2.3, Eq. (17) Reflection Coefficient for Power Maximization
with subspript ‘P’ added to left side to make it distinguishable from (5).
  • Takuichi Hirano, REVIEW AND ANOTHER DERIVATION OF THE POWER WAVE,
Department of International Development Engineering, Graduate School of Science and Engineering, Tokyo Institute of Technology
2-12-1-S3-19 Ookayama, Meguro-ku, Tokyo 152-8552, Japan; Corresponding author: hira@antenna.ee.titech.ac.jp
© 2015 Wiley Periodicals, Inc. https://onlinelibrary.wiley.com/doi/epdf/10.1002/mop.28766
p. 26, eq. (5) and (27)
reflection coefficient
  • Prof. H. A. Haus, Prof. P. L. Penfield, Jr., Prof. R. P. Rafuse, W. D. Rummler, NOISE IN ELECTRON. DEVICES,
this work was supported in part by Purchase Order DDL B-00306 with Lincoln Laboratory, a center for research operated by
Massachusetts Institute of Technology, with the joint support of the U.S. Army, Navy, and Air Force under Air Force Contract AF 19(604)-7400,
ch. 2 wave representation, p. 67, eq. (17), reflection coefficient of the source, with being the conjugate
source impedance used as reference impedance in the Smith Chart Center, . DJ7BA (talk) 12:01, 20 May 2022 (UTC)
DJ7BA (talk) 12:08, 20 May 2022 (UTC)
Please excuse: Something got garbled in equations above. I don't know why. Just disregard the '::::::::' in two of the equations, please. No idea, how that happened.
I hope, nothing else was garbled. DJ7BA (talk) 12:08, 20 May 2022 (UTC)
Once again, this largely your original work, and cannot be in the article per WP:NOR. You seem to fundamentally misunderstand Wikipedia - we're not an indiscriminate collection of information. Just because something can be proven correct does not mean that it should be in an article here. MrOllie (talk) 12:18, 20 May 2022 (UTC)
So what is "largely your original work"? Quote it, please, explain it, and suggest your improved wording to eliminate any perhaps still existing problem.
Where exactly is still any "WP:NOR" as you claim, MrOllie?
There is a possibility that you perhaps didn't read enough source context. I chose my wording pretty close to what is written there. That is is much material, and your answer was fast.
But it is also possible that I forgot to mention something that could be important to you to understand that there is no WP:NOR any more.
But if it is: Let's find it. And: Let's work together towards getting it well done. Will you? 2001:16B8:2D2D:D100:F9F9:9CF9:4639:F4D5 (talk) 18:09, 20 May 2022 (UTC)
Sorry. You don't get it. Four experienced editors with advanced knowledge of the subject have attempted to explain to you that your proposed additional material is not suitable for Wikipedia. This discussion has become WP:TENDENTIOUS. It is time to close the discussion. Constant314 (talk) 19:01, 20 May 2022 (UTC)
DJ7BA (talk) 08:32, 21 May 2022 (UTC)
1. The subject relevant impedance mismatch coefficient, that is still missing in "Impedance Matching", is supported by 8 notable, reliable sources. No doubt is possible.
2. To avoid WP:NOR, I was very careful not to use any idea or thought not written in the sources.
3. This is not "WP:TENDENTIOUS", but is exactly what you told me to do. DJ7BA (talk) 08:32, 21 May 2022 (UTC)

DJ7BA (talk) 08:52, 5 June 2022 (UTC) I have fully understood WP:TENDENCIOUS. It sais:

If what you want to say is genuinely verifiable, then it should be possible to find at least one reputable and respected authority who says the same thing in pretty much the same words.

Please read the Stutzman Thiele Source.

It sais: "... by noting, that the received power is the incident power (normalized to unity) less the relative reflected power"

Unity means 1, relative is relative, and less without any doubt describes a difference. Consequently eq. (4-41) is a relative difference:

I use pretty much the same words "relative difference" for the same thing, the received power q. The alleged WP:NOR is not possible.


Yes, I also used "relative difference" for

But if is a relative difference, what kind of "Research" does it take to understand, that then also ?

If , is it asking too much from a 10 year old reader to understand that also  ?


I think, one thing here is appropriate in what WP:TENDENCIOUS sais, 3b:

WP:AOTE

"Making accusations of tendentious editing can be inflammatory and hence these accusations may not be helpful in a dispute. It can be seen as a personal attack if tendentious editing is alleged without clear evidence that the other's action meets the criteria set forth on this page, and unfounded accusations may constitute harassment if done repeatedly. Rather than accuse another editor of tendentious editing, it may be wiser to point out behaviours which are contrary to Wikipedia policies such as WP:NOR, WP:RS, WP:NPOV, and the 3RR rule. See also: WP:AOHA and WP:ASPERSIONS."

I had kindly asked for quotation of what was meant exactly, and explanation. But MrOllie was predetermined. So he quickly responded with unsupported WP:NOR. But at least his response was too fast to read the source I gave.

Constant314 simply agreed with MrOllie, and mentioned 2 more "experienced editors with advanced knowledge of the subject have attempted to explain to you that your proposed additional material is not suitable for Wikipedia."

So, neither MrOllie, nor Constant314 so far has given evidence of their alleged WP:NOR or WP:TENDENCIOUS, nor have the two more mentioned. Instead of reading and explaining, no answer.

One can only conclude that the alleged WP:NOR and WP:TENDENCIOUS are unsupported and thus must be considered not acceptable, ifr not reasonably explained.

Theory

DJ7BA (talk) 08:54, 8 June 2022 (UTC) Wiki paraphrasing:

"You are supposed to use your own words to paraphrase ... I get the feeling that you do not understand the meaning of paraphrase. It has a very narrow meaning ..."

It sais:

... " In the following summary we will consider the general case when resistance and reactance are both significant, and the special case in which the reactance is negligible."

Reflection-less matching

"Impedance matching to minimize reflections is achieved by making the load impedance equal to the source impedance."

No!

Impedance matching making source impedance and load impedance equal is not reflectionless matching, as the line is missing. Some medium (i.e. a line) is needed for a moving wave to be reflected.

Instead, this sentence should read:

"Impedance matching to minimize reflections on a transmission line is achieved by making the load impedance equal to the line's characteristic impedance."

Then following this:


"If the source impedance, load impedance and transmission line characteristic impedance are purely resistive, then reflection-less matching is the same as maximum power transfer matching.[1]"

No!

"You are supposed to use your own words to paraphrase reliable sources. ... I get the feeling that you do not understand the meaning of paraphrase. It has a very narrow meaning ..."

This is a false, misleading oversimplification, not a narrow paraphrasing of the source [1].
That "paraphrasing" ignores the necessary two matching networks for matching the resistances, too.
Only these ignored networks provide the result. The source - but not it's "paraphrasing" - is clear:

1. "Chapter 6.4.2 Matching Networks"
2. Reference to Fig. 6-30b on page 176, that shows a system with source, line, load, but also with two matching networks:
a. The one on the left provides for conjugate matching, thus assuring maximum power transfer from the source into the line.
b. The one on the right provides reflectionless match between antenna impedance and characteristic impedance of the line.

Without these necessary conditions described by the source, the oversimplified sentence is misunderstandable in that it could apply for three impedances of i.e. . Without the matching networks, the misleading sentence generally results in non-maximum power transfer, and in reflections on the line.

Suggestion:

1. Improve the sentence to include the matching network needs
2. Move it to section "Impedance Matching Devices"
3. Or: Simply cancel the oversimplifying sentence.

  • I agree that "If the source impedance, load impedance and transmission line characteristic impedance are purely resistive, then reflection-less matching is the same as maximum power transfer matching" is incorrect. If the source impedance and the transmission line impedance are different, even if purely resistive, then the impedance seen at the load can still be reactive. In that case the reflectionless load impedance and maximum power impedance would not be the same. Good catch. Constant314 (talk) 15:53, 8 June 2022 (UTC)
DJ7BA (talk) 08:36, 9 June 2022 (UTC)
Thank you for your agreement with respect to issue 2.
I will now cancel the wrong sentence. It is unnecessary at that place.

How about your understanding of issue 1 ?
The wrong sentence sais:
"Impedance matching to minimize reflections is achieved by making the load impedance equal to the source impedance." (emphasis here in talk by me)

No reliable source is given. This alone might be considered enough reason to cancel it. But worse than that is: It is false:

It misrepresents the correct derivation further down the page, that under "Transmission line", subheader "Load-end conditions" sais:
"... where the reflection coefficient going from the transmission line to the load", but not "from the source to the load". (emphasis here on talk by me)

Correct is:
Reflections on a line are caused by an unequal load impedance terminating the transmission line having a different characteristic impedance.

You (thank you) already had agreed earlier that the so called ATIS and IEC (reflection coefficient and return loss) "definitions" are errors:
They claim equal equations for what is
1. source load impedance (mis)match, causing non-maximum real power transfer,
2. and for a line load impedance (mis)match, causing reflections on a transmission line.
By (mis) I mean, that the two different, currently still reverted mismatch equations, each validly cover both, match and mismatch.

How comes, that this error could prevail that long with many (at least 4) expert editors and even more readers?

The false sentence must have been written and read by victims (like ATIS and IEC) of that confusion, that "source or characteristic impedance? Why bother: both are the same anyway"
This is not just a simple mistake that easily can happen. Don't feel bad. It rather is typical for a school of teaching [2], being error victim, too. If anyone is a leading top expert, Ward Harriman is.

[2] Ward Harriman, Coping with Complex Zo, p. 3, https://www.dropbox.com/sh/amedlefruc0zol1/AABmHqvp5yIkD7SA5wROb_AMa/pdfs?dl=0&preview=ComplexZo.pdf,
"I am of the school who believes..." "... are all attempts to give a name to the phenomena of reflection."
"Transmission lines may help with visualisation, but the principles are more universal.
They are simply a measure of the impedance mismatch between a source and a load."
DJ7BA (talk) 08:36, 9 June 2022 (UTC)
  • I agree that the statement "Impedance matching to minimize reflections is achieved by making the load impedance equal to the source impedance" needs attention. The problem is that it is unclear as to what reflection is being minimized and exactly what is meant by source impedance and load impedance. In the case of a transmitter driving a load through a transmission line, there are two points at which reflections are typically considered.
  • If the reflection at the load and back into the transmission line are to be minimized, then the load impedance should be selected to be the same as the characteristic impedance of the transmission line. Everyone agrees that this minimizes reflected waves in the transmission line.
  • There is a community that are concerned with the reflection at the transmitter and reflected back into the transmitter. This community is not concerned about reflections in the line. They are concerned that the impedance as seen by the transmitter is the impedance that the transmitter is specified to drive; typically, this is either 50 or 75 ohms. For this community, load impedance refers to the impedance presented at the transmitter by the combined effect of the transmission line and the actual load. Source impedance refers to the impedance specified for the transmitter. Reflections at the actual load are fine so long as the impedance at the transmitter is correct. Usually, the specified load for a transmitter and the output impedance of a transmitter are the same. For this community, hence, usually means both the output impedance of the transmitter and the transmitter's specified load impedance.
  • Given the ambiguity, I will remove the offending section.  Constant314 (talk) 19:24, 9 June 2022 (UTC)
    Thank you for your great understanding of the problem. I do 100% agree with your reply.

    Yes, there is, what a large community calls reflections and/or reflection coefficient, though rigorously speaking it can be considered a misnomer, promoting ambigouity and confusion.

    According to Shepard Roberts, who in 1946 published the difference of the two coefficients and who also provided the derivation, this is called "reflections" or "reflection coefficient" with quotation marks. And he added 'by analogy with transmission lines' and pointed out the different type of 'image base' ('Usual image base' vs. 'Conjugate image base'). [3].

    S. Roberts is 100% clear to the attentive reader. Unfortunately he didn't foresee that "reflection coefficient" and reflection coefficient all too easily would soon be confused by simply omitting the quotation marks, the analogy remark, and the image base.
    By S. Roberts description, the (so misnomed) respective reflection coefficient at the transmitter and reflected back into the transmitter is
    If he would have imagined the resulting falsification of what he correctly presented, I am pretty sure he would have used an unambigous, descriptive name instead (such as Source Load Impedance Mismatch Coefficient).

    I am fully aware that the use of the misnomer reflection is so overwhelmingly often, that we will not change the tide. At least not in the near future. We have to accept that this is common use. However, we may point out that anyone concerned about avoiding ambigouity should also use an inambigous addition to show what is meant, and if not, the reader should find out himself always, so he is not mislead.

    What do you think: Shall we add a section "Source and load impedance Mismatch", narrowly paraphrasing S. Roberts, following section "Transmission lines" ?

    [3] Shepard Roberts, , Conjugate-image impedances, Member I.R.E,
    https://worldradiohistory.com/hd2/IDX-Site-Technical/Engineering-General/Archive-IRE-IDX/IDX/10s/IRE-1946-04-OCR-Page-0081.pdf
    Proceedings of the I.R.E. and Waves and Electrons, volume 34, number 4, Section 1, April 1946
    p.199 P, eq. (3a) “reflection coefficient” , Fig. 1-Equivalent circuit of generator and load.

For introduction and end of the article, please change "0081" in the link to "0080" or "0082". DJ7BA (talk) 12:19, 10 June 2022 (UTC)

We can't use Roberts as a source for a 'mismatch' in terminology. He didn't write about it (how could he? By your own explanation it would not have happened yet). What you are proposing is (once again) WP:OR. We cannot infer anything beyond what is in the plain text of the cited sources. MrOllie (talk) 12:39, 10 June 2022 (UTC)
I think that we need some agreed on terminology. I will start a new talk topic on that. Constant314 (talk) 19:38, 10 June 2022 (UTC)
I see what MrOllie means. May I suggest, that you, Constant314, do the narrowly paraphrased writing of what the S. Roberts Article has to contribute to what in other words is the main subject "Impedance Matching".
That way we avoid my perhaps again somehow attackable terminology. By your experience you are better aware of wiki pitfalls. So we don't infringe anything and save time. I will proofread it technically then. I feel adequately qualified for that.
@ MrOllie: If worst comes to worst, we would have to create a subsection ' reflection coefficient vs. "reflection coefficient" '

But please don't overstress mere formalism, as long as it doesn't help the goal of improving the page.
Important is: S. Roberts is an excellent, truely reliable source for the equation and it's derivation. I do not agree to omit it completely. DJ7BA (talk) 08:46, 11 June 2022 (UTC)
We wouldn't create a section about a quoted and non-quoted version either, not without a source that specifically discusses that. Frankly, I don't think such a source exists. This is not a 'formalism', it is one of Wikipedia's core policies. We do not make up new material out of whole cloth. MrOllie (talk) 11:09, 11 June 2022 (UTC)
I can (though not without some head shaking) accept to have to drop the word "Mismatch". Why head shaking?
Anyone knows immediately impedance matching is meaningless, unless there is some mismatch to be taken care of.
As far as I can see, there is no need to explain or to support the use of the word "Mismatch" by a reliable source. It' scommon knowledge. If not enough:
People, who want to know about "Impedance Mismatch" are redirected to this page. Should it - really - not talk about impedance mismatch?! (Head shake).
The article already, without quoting any reliable source, mentions: "... ways to improve an impedance mismatch, all of which are called "impedance matching".
Why should that present a problem, just when I use it? I cannot see it.

But let's move forward:
S. Roberts specifically discusses, what is absolutely pertinent to the page "Impedance Matching"
  1. The Problem of optimum Impedances
  2. Determining the optimum impedances
  3. Conjugate image Impedances
  4. Load impedance connected to a source of signal "matched" to the impedance of the generator
  5. Impedance matching on the conjugate-image basis
All these are possible subheaders. They, together with a paraphrase of the article contents, including the derivation given, fulfil the requirement of specifically discussing the material deemed necessary for this page on "Impedance Matching".
I suggest for subheader the above nr. 5. Impedance matching on the conjugate image basis.
Any objection or other preference? DJ7BA (talk) 15:29, 11 June 2022 (UTC)
DJ7BA (talk) 17:59, 12 June 2022 (UTC)
I must explain what I mean by "don't overstress mere formalism, as long as it doesn't help the goal of improving the page":
  1. To my so far findings, you are not an expert in RF electronics: Your answers on technical RF subjects are vague, more of the type: "I dont' really believe that ...", but without actual RF expert's technical reasoning.
  2. To my so far findings, you are an expert in selfpromoting: by seeing your own honor by trying to get a high ranking on the list of Wikipedians by number of edits: Your edit count was close to 100.000 at some not so recent wiki list. .
These two components probaly caused you not read through an article that used "less" and "relative" in describing exactly what I earlier had called "relative difference", but now could support by reliable source saying "less" and "relative" on the same subject.. Instead you immediatly called it WP:NOR - within 10 minutes after my list of 8 reliable sources on the subject. You simply could not have studied the material carefully in such short time, and having no real RF electronics expert's knowledge - why should you. If you had, you would have seen that in essence the article desribed the same thing that I did. But, instead of trying to compare, you didn't even take the time to find and read the reliable sources I gave..
"Pretty much the same thing with my own words" is considered paraphrasing by wiki rules, and it is deemed necessary by wiki rules for avoiding copyright conflicts. "Pretty much the same" doesn't mean "zero difference in words".
There is just the question: How narrow the paraphrasing must be or how different it may be. This is a matter of discretion. WP:NOR is not defined in like 3,14 < , and 3,15 > . No, there is some discretionary room for interpreting a wiki rule.
The same thing applies to indexing. If I give 8 reliable sources all discussing the subject of derivation of a coefficient describing mismatch between source impedance and load impedance, but they use - in the context of what their article covered before - slightly different indexing: That dowesn't mean they describe somthing else. It means, they describe what positively supports the subject in the article. WP:NOR accustion because of such Indexing differences as all using the same equation (don't complain here again, ithe Z indices can differ in the different sources, too) all have the same contents. They all represent some source load impedance mismatch equation.
If I cannot use them, because they differ - not in any way by meaning, just by indexing - this is "mere formalism", as I understand it, too. As far as I can see, Such Index complaints are unnecessary and nothing but pretext for the sake of quick edit count honors.
You seem to care less about a newcomer's intererest in improving page content by helping them to find an acceptable way or paraphrasing, by suggesting wording that you would not revert. This would really improve wiki pages.
Instead you seem to see your honor in being an edit number scoring type of expert. You certainly get more points faster by not being any help, but by fast reverting as many edits within as little time as possible.
That type of behaviour certainly is not forbidden. It does, however, lead to my impression that you overstress mere formalism: The impession you leave is that you have no genuine interest in the goal of improving the page quality.
I have the intention of improving the page by some contribution of RF expert knowledge within my own limits, and at the same time to fully observe all relevant wiki rules by the genuine reason for the rules - not by mere foramlistic application.
When it comes to adequate discretion, you don't take the time to understand difficult technical contents, but you exploit the span of disctretion of what is WP:NOR or what not to an unbearable onesided, overly narrow interpretation,
That only helps your fast scoring. This is overstressing formalism - as I see it. But it certainly doesn't help contents quality.
There are real technical experts in the RF electronics field. Constant314 is one. He, too, is an experienced wiki editor at the same time.
He has invested much time and contributed much RF expetr't knowhow. Thank you so much, Constant314. MrOllie, Take him as an example of a real good editor.
If he sais anything on wiki rules to me, I am fast to learn and will accept it. Honor should go to such genuine experts instead of relentless edit score hunters.
I would be most thankful to you, if you coul leave discretion to good RF and Wiki experts like him - please.
I am sure that you again will have some sort of wiki rule excuse - like you always have. I don't expect - based on your documented behaviour - that you will really understand and accept the above.
I expect that you will want me to always think the best intention of other editors. Yes, I do expect the best of you.
You certainly don't want to harass editors unnecessarily. This is not what I want to say.
And also I must accept that you don't have to be helpful in finding accepatble solutions.
Anyway: This is how I feel: It is "overstressing mere formalism, as long as it doesn't help the goal of improving the page".
Maybe, other reverted editors feel with me.
You have reverted thousands of editors on whatsoever subjects they wrote on wiki. You simply are not expert in all these fields.
Often reverting is very necessary indeed to enforce the good reason for wiki rules. Example: sales promotional spamming etc.
But more than never it could also be score hunting, overstressing mere formalism, or, in other words:
Casualistic, hairsplitting rule interpretation.
Thanks for whatever degree of understanding you may have.
Sincerely, DJ7BA.
DJ7BA (talk) 17:59, 12 June 2022 (UTC)
I must explain what I mean by "don't overstress mere formalism, as long as it doesn't help the goal of improving the page":
  1. To my so far findings, you are not an expert in RF electronics.
  2. To my so far findings, you are an expert in selfpromoting: by seeing your own honor by trying to get a high ranking on the list of Wikipedians by number of edits: Your number was close to 100.000 at some not so recent count at least.This
DJ7BA (talk) 15:41, 12 June 2022 (UTC)
Wow. Knock off the personal attacks. Lashing out when people disagree with you isn't going to help you gather consensus for your proposed changes. MrOllie (talk) 15:47, 12 June 2022 (UTC)
Somehow I prematurely relleased a part only. Fat fingers. Sorry. Please read the complete thing. It is not an attack - as you can see I respect your rights.
It is an expression af a newcomer's feeling, who seriously tries to understand what wiki rules really mean, indeed.
Disagreeing? I am totally open for sincere discussion on the subject of the page, and on the reason for wiki rules. I can fully agree with, and don't argue on what they want to regulate,
That is not "personal attack". But it must also be possible to explain what is deemed "overstressing formalism", not wiki consistent page improvement.
It's well meant critic, and yes, it is personnal, but no attack. DJ7BA (talk) 18:17, 12 June 2022 (UTC)
Is English your first language? Your writing style is quite difficult to understand. That appears to me to clearly be a set of personal attacks. I read it as: You questioned my expertise, said I'm here to selfpromote, and told me to leave the discussion. Perhaps we are simply having difficulty communicating. MrOllie (talk) 19:38, 12 June 2022 (UTC)
Maybe so. I mean page improvement by substantial contents. Not "attack", nor "selfpromotion" by wiki rules, (referring to financial interest), nor to leave.
Any discussion on RF engineering substance by anyone is welcome.
So is any english improving edit by anyone.
So is any WP:something that is not mere formalism for it's own sake. But:
So far I have not found a single RF engineering substantial contribution from your part, I certainly didn't read all your some 100.000 edits.
I was told to accept what 4 experts say. That included you. So I differentiate what type of expertise you have.
It would be very easy for you to show that you have given at least one single substantial RF engineering wiki contents contribution.
If so, I fully must apologize for even mentioning your RF engineering expertise.
Referring to your user's page, I found some 16 archives, each having some 100+ cases.
I didn't read all these, but enough to see a pattern: I found not one single humble word from your part like "sorry, I went too far" or similar.
Instead, I got the impression that you must be a 100% perfectionist, who always is right. You are welcome to show that this impression is wrong.
I do not question your right for seeking honor, nor your right for your own understanding of what honor means. Go for it - as long as you don't
unnecessarily revert contributors by mere formalism.
Do you mind me preferring real RF engineering expert's knowledge to improve a RF engineering relevant page?
It is no wonder they find my open ears for any RF engineering substantial talk, as well as open ears for any WP:something they help me to understand.
This is highly appreciated, no matter who it is.
If someone doesn't even take the time to read the reliable source supporting my contribution, but already claims it is WP:NOR anyway, it is no doubt that
I have preferences and suggest to rather discuss with RF engineering experts who do read and who do understand. They and I have spent much precious time to improve the page.
A quick reverter who doesn't take the time to read and to understand, certainly is not my preference. I prefer you to wait until we are done. That saves time and improves the page. DJ7BA (talk) 09:04, 13 June 2022 (UTC)