“The definition of genius is taking the complex and making it simple.” - A. Einstein. Brilliant channel. Credit to all involved.

@pauldenisowski

26 күн бұрын

Thank you!

@josehenriquemaia136

23 күн бұрын

Gênio!!! Parabéns!!!​@@pauldenisowski

excellent video, thank you, those 5 dislikes probably from keysight

@ethendixon4612

4 жыл бұрын

Lollll prolly from Keysight

@JotaEseUveA

3 жыл бұрын

3 from keysight, 2 from anritsu XD

@annguyendang8388

2 жыл бұрын

Why did you think of that?

@tonofgx531

2 жыл бұрын

@Alter Kater Yeah that kind of bothers me as well. The video assumed that the source is perfectly matched to the tline

@pranaysharma1255

2 жыл бұрын

😂😂😂

I am now 66 retired and way back in 1985, I took a 9 month course of Microwave electronics at Microwave Training Institute in Mountain View, California, a school privately owned by Alan Scott. Learned the basics, Operation of Klystrons, Reflex Klystrons, low frequency circuits, microwave circuits and laboratory experiments using microwave instrumentation and USE OF THE SMITH CHART. This video VISUALIZATIONS are awesome and I HAD A HARD TIME visualizing what those PHYSICISTS and Working Engineers teaching us those concepts, I finished the course knowing all these magic microwave skills and went to work at a few companies building microstrip gallium arsenide microwave amplifiers 4 - 18 Ghz at the time tuning and cascading them, with a lot of microscope work. Thank You for MAKING this VIDEO, the time and dedication you have explained these concepts in simple clear manner. God Bless You.

I just found the Gold mine, and the fact it comes from my favorite Test&Measurement company is icing on the cake.

@pauldenisowski

8 ай бұрын

We're happy you're here - and more is on the way!

excellent delivery and I am in the Telecommunication field for the past 40 years and I am impressed.

@pauldenisowski

4 жыл бұрын

Thanks Richard - really appreciate the feedback!

That graph at min 5 was all that i was needing.

@pauldenisowski

3 жыл бұрын

Thanks -- sometimes a picture really is worth a thousand words :)

MAN this helped so much. Im final year doing electrical engineering and my teacher speaks no English and i was FREAKING out until i found your video. Thanks mate

This is one of the best and easy to understand explanation with clear examples I have come across. Well done team. I request you to post more such videos.

I'd like to make three important points, all of which can be easily proven as fact: 1.) Reflected power is absolutely NOT what damages a PA device or stage. It is the mismatch in optimum impedance at the output port, regardless of standing waves or reflected power on the feedline some distance away from the PA stage. 2.) It is quite possible to have a very high percentage, actually nearly 100%, of transmitter power delivered to a load even with a very high "reflected power" or VSWR. 3.) Many antenna systems, as well as PA matching, splitting, and combining systems, intentionally operate with fairly high standing waves. Collinear antennas, like VHF/UHF multiple bay arrays, commonly use mismatched transmission lines in harnesses to split power and match the multiple elements to the feed impedance. These harnesses and cables often operate well over 2:1 VSWR in the feed cables with negligible loss.

Beautifully made presentation/explanation. 5/5!

@pauldenisowski

8 ай бұрын

Thank you!

Thank you so much for the explanation and the concept. Your way of your explanation is easy to understand, preety straightforward but still bring the concept. Hope the best for you

One of the best lectures I have ever come across. Thank you so much sir!

@GuruGyancenter786

Жыл бұрын

Good

Amazing and very valuable for someone like me been over 10 yrs in field

What an excellent video, more like this please!

Excellent presentation on understanding the Return loss and importance of VSWR.

I like this comment and it is spot on. The pacing of the speech and clarity videos is just right in an area of Radio Frequency engineering that is not easy to grasp. No wonder Rhode and Schwartz make the best analysers in the industry. I wish I could afford to buy one.

@pauldenisowski

10 ай бұрын

Thanks!

At 63, I find this the best explanation so far. The explanation is exactly the same as everyone else's, (so it would be, wouldn't it!), but the waveform animation is slower and easier to understand, with the explanation at a well measured steady pace. Thank you R&S, this video should be played in college courses.

@RohdeundSchwarz

4 жыл бұрын

Thanks a lot for the positive feedback - that motivates us!

@pauldenisowski

4 жыл бұрын

Thank you!

@Tom-dn5de

2 жыл бұрын

@@pauldenisowski Thanks for the great video! and I have some things to ask. The frequency of the reflected signal is the same as the frequency of the forward signal or not? And how about the relative phase between them?

@pauldenisowski

2 жыл бұрын

​@@Tom-dn5de Generally speaking, the signals appearing at all ports of a network will have the same frequency as the input signal but different phases and amplitudes. It is possible to make S-parameter measurements on frequency-converting devices, but this is a more advanced topic that needs its own video :)

@Tom-dn5de

2 жыл бұрын

@@pauldenisowski Thanks a lot for your explanation. I am taking a VSWR measurement of an RF source, but I don't know why an auxiliary generator is used which transmits a wave with a slightly offset carrier frequency into the DUT. Could you explain it to me?

SUPERB. What a great explanation.

A clear and good presentation. Thank you.

To the point and very informative. Thanks a lot for the share!

Beautifully explained..

Excellent presentation!

@pauldenisowski

4 ай бұрын

Thank you!

Paul..... in my 76 years I have seen a "FEW" VIDEOS. THIS ONE IS BY FAR THE BEST and clearest I have seen. on this subject. Coming from your company, i am not surprised, Rhode & Schwartz are well known for the top quality of their instruments. Thank you for taking the time and effort in producing this. Please rest assured that it is VERY MUCH appreciated. IGNORE the dislikes... Even if God himself would have done this video... he too would get dislikes... and probably more of 'em ! Albert EI7II.

@pauldenisowski

2 жыл бұрын

Thanks for the support! There are always things that I could do better in these videos, so I appreciate any and all comments. 73, Paul KO4LZ

@deepeshshiwakoti7249

9 ай бұрын

What a wonderful comment.

Thank you! Such a beautifully explained video!

this helped me through HF/RF Engineering thanks

Thanks for the great video! I hope more to follow!

@pauldenisowski

4 жыл бұрын

Thanks! We just posted a series of videos on oscilloscopes today and there will be many more videos in this series, so please stay tuned!

most understandable vide I saw on that topic. great job

@pauldenisowski

3 жыл бұрын

Thanks!

i swear its james woods doing these lessons. great content though and i really appreciate the education. its been extremely helpful. ooh a piece of candy.

very nice presentation

Absolutly great presentation!!! Thank you!

@pauldenisowski

Жыл бұрын

Thanks for the feedback!

Just getting into amateur radio, this is very helpful.

Wow superb video! Thanks!

Very informative. Thanks.

@pauldenisowski

8 ай бұрын

Thanks - appreciate the feedback!

Excellent, Excellent, excellent video! THANK YOU!! I subscribed...

Clearly explained the content. thanks for making Video .

omg this video was so informative; thank you a tonne

excellent explanations... thank you

great, thank so much for that knowledge you provided

Another fantastic video, summarising what my lecturer failed to convey in 2 hours in 10 mins! Love this series!

@pauldenisowski

3 жыл бұрын

Thanks! There is obviously a LOT more than can be said about VSWR and return loss (not to mention all the underlying theory and math), so we try to focus on the basics :)

Excellent video sir..... it helped me understand the thing. Thanks a lot !!!

Very well presented.

Coming from an avionics background, this video was beneficial since it was only briefly mentioned, and it was more about hooking equipment up, and it will measure it for you. This will definitely be used to help teach others what VSWR is. Thank you.

@pauldenisowski

Жыл бұрын

Thanks!

very nice and clear explanation. thank you for not just this but the whole video series. very informative on basics. just want to point out a possible typo at page 13 where Return Loss and VSWR are related via an equation. here the numerator and denominator are switched somehow i.e. it should have been Return Loss = 20log10(VSWR-1/VSWR+1).

Thank you. You filled a gap in my knowledge. I repeatedly ran too much power for a GC MS and had a foldback circuit shut the power down. The field engineers could not explain this to me. It did not help that I had no meter to let me know I was approaching the power limit. Thanks again. N0QFT

@RohdeundSchwarz

Жыл бұрын

😎 👍

@RohdeundSchwarz

Жыл бұрын

That's great to hear Glen! Thank you for the feedback

@pauldenisowski

Жыл бұрын

Glad it was helpful. Foldback has saved me from destroying quite a few things in my career :)

Thanks for the clear explanation!!

@pauldenisowski

Жыл бұрын

My pleasure - thanks for the feedback!

Really helped me understand the topic ! you're a great teacher.

2:46 example of complex impedance - antennas and that is why there is a range of frequency mentioned. Therefore the level of power reflected will be a function of frequency. There are two ways to quantify these losses 1. VSWR 2. return loss Retrun loss= Forward power - reflected power for example - Forward power is 50dBm and reflected power is 10dBm Return loss = 40dBm The larger the return loss the lesser the reflected power

Thanks, this is so pleasant to learn from.

@pauldenisowski

2 жыл бұрын

Thank you!

Very helpful!

amazing video

that was really helpful. Thanks for the content.

@pauldenisowski

2 жыл бұрын

Thank you!

Loved that❤❤❤❤❤❤

@pauldenisowski

2 ай бұрын

Thank you!

This is great stufff

thank you so much

amazing explanation thanks sir

@pauldenisowski

2 жыл бұрын

Thanks for the feedback!

For the matching network (at 8:14), what would you need to do if the source impedance was smaller than the load impedance? Would the matching network have to have some sort of ADMITTANCE to get the source and load to match? Or is it just not possible to do so?

Very good 👍😊

I didn't know actor James Woods was into antenna efficiency! :)

I'm trying to troubleshoot a high voltage power transmitter with valuable freq.. Problem is an over current fault which shuts down the transmitter. This video is helpful, TY

@pauldenisowski

2 жыл бұрын

Thanks and good luck!

Thank you

Excellent video, how you got percentage of return loss ?

Great video. I got stuck when trying to find the ratio of reflected power to forward power by the Vswr. Is there an equation that converts Vswr to the amount of reflected power?

@RohdeundSchwarz

4 жыл бұрын

Dear Richard, for calculating VSWR using power instead of voltage, you can use the following formula: VSWR = (1 + p) / (1 - p), where p = sqrt(reverse_power / forward_power). Best, Rohde & Schwarz Social Media Team

@munazzahtaimuri3585

4 жыл бұрын

@@RohdeundSchwarz If above formula is to be used fo this conversion, when should we use the the formula mentioned at 6:12 relating return loss and VSWR?

Thank you for your brilliant explanation. One question on terminology though: should we use something like "effectively transmitted power" intead of "return loss"? I doubt "return loss" is the proper term to use in this case because we are discussing the energy, which has been absorbed by the antenna and has been radiated into ester. I know this is not your invention. I wish to know your opinion.

@pauldenisowski

4 жыл бұрын

Hi Yaroslav - Thanks for your comment. "Return loss" is the standard industry term for this measurement, but I will agree that this term can be a bit problematic. In fact, the editor-in-chief of IEEE Transactions on Antennas and Propagation published a short article in 2009 describing the origins and proper use of the term "return loss" -- it appears close to a third of the people submitting papers to this journal were using the term incorrectly. (Link below, available to IEEE members). From the article: "Turning to present-day usage, return loss is now the most common term used to describe reflection and mismatch." ieeexplore.ieee.org/document/5162049?arnumber=5162049

@yaroslavmuradian5959

4 жыл бұрын

@@pauldenisowski Thank you Paul. I will look into it.

so nice！

@pauldenisowski

Жыл бұрын

Thank you!

Will the IL,RL characteristic value change according to the reference input to the POGO connector? For example, Will the IL change according referance input 0dBm Vsersus 35dBm?

About impedance matching, if i have a Source impedance of 50ohms, Line RG6 75ohms, and a 25ohms load impedance(microstrip antenna). Is this a matching set with less reflected power? How much VSWR do you think I'll get from this setup? Thanks

@pauldenisowski

4 жыл бұрын

Unless the load is purely resistive (and your antenna almost certainly isn't), the VSWR will be a function of frequency -- i.e. it will change depending on the frequency of the signal generated by the source. In most cases, the easiest way to minimize reflected power is to have a source, load, and line impedance that are all as similar as possible. Even though a lot of people successfully use RG6 with 50 ohm sources, you might want to consider a different cable type. There's not much you can do about the impedance of the antenna, but keep in mind that this may also change based on how and where the antenna is mounted (i.e. what's next to it). It can be very difficult to reliably and accurately determine VSWR based on the (nominal) values of components in a system. I can do the math and calculate how long a dipole *should* be to have a given VSWR over a given frequency range, but when I actually build it and hang it from a tree or (especially) in my attic, the VSWR is never precisely what I calculated (and is sometimes quite different). The math may give you a good starting point, but the actual value of the assembled system will often be at least somewhat different. This is one of the reasons why instruments like network (or antenna) analyzers exist -- measurement is the only reliable way to know for sure what your VSWR actually is. Hope that helps!

8:16 why there a circuit about capacitor and inductor? I thought we are talking about impedance.

Wiki _From a certain perspective 'Return Loss' is a misnomer. The usual function of a transmission line is to convey power from a source to a load with minimal loss. If a transmission line is correctly matched to a load, the reflected power will be zero, no power will be lost due to reflection, and 'Return Loss' will be infinite. Conversely if the line is terminated in an open circuit, the reflected power will be equal to the incident power; all of the incident power will be lost in the sense that none of it will be transferred to a load, and RL will be zero. Thus the numerical values of RL tend in the opposite sense to that expected of a 'loss'._

@tomaszkluska6419

2 жыл бұрын

RL should have the name unloss :))

@pauldenisowski

2 жыл бұрын

I agree completely that the term "return loss" is very problematic. As I've mentioned a few times in the comments, it's confusing even to RF engineers, so much so that the editor of an IEEE journal had to publish an article explaining the "proper" way to use the term :)

Sir, your idea of vswr is different from what some materials say. They say vswr is ratio of voltage max at the peak and voltage minimum at the trough/bottom. Your explanation of it in the graph appears different. Also, textbooks don't mention that impedance matching means load impedance is the complex conjugate of the source or line impedance. They say it should be exact match. Could you please clarify. Thanks in advance.

@SteveWithnell

2 жыл бұрын

The complex conjugate provides the exact match. This calculator might be helpful to play around with: www.analog.com/en/design-center/interactive-design-tools/rf-impedance-matching-calculator.html

The terminology of Return Loss for me is very counterintuitive. Instead of difference Forward - Return power I would rather use the ratio of Return / Forward. As we call it Loss how can we strive to maximize the number? Loss should be a low number, or low percentage.

Is it correct ? At 4:32, it shows that Forward power -reflected power= return loss. I assume the return loss = reflected power. Who is wrong?

@RohdeundSchwarz

2 жыл бұрын

Hi, thank you for your feedback. This is correct, yes.

@4:30 40dB or dBm ?

@pauldenisowski

4 жыл бұрын

If the forward and reflected powers are in units of dBm, the difference between these values (X dBm - Y dBm) will be in units of dB (not dBm).

@43SunSon

4 жыл бұрын

@@pauldenisowski ?? i thought dBm-dBm=dBm. could you please explain more or give me an example ?

@pauldenisowski

4 жыл бұрын

@@43SunSon Sure :) One of the more common "rules" when it comes to decibels and logarithms is that reducing a value by 3 dB is the same as decreasing it by one half. The difference between one watt (30 dBm) and one-half watt (27 dBm) is .... 3 dB. The power value 3 dBm is approximately 2 mW, not one-half watt. Rohde and Schwarz actually has a whitepaper that explains this and quite a few other things regarding decibels: scdn.rohde-schwarz.com/ur/pws/dl_downloads/dl_application/application_notes/1ma98/1MA98_13e_dB_or_not_dB.pdf Hope that helps.

@43SunSon

4 жыл бұрын

@@pauldenisowski oh my man! you did well! I am reading that pdf. How did you know that much? Are you in this area as well?

@pauldenisowski

4 жыл бұрын

@@43SunSon Thanks. I'm an engineer at Rohde & Schwarz working in radio frequency test and measurement, so I deal with dB all day, every day :) If you're interested in learning more about RF, please check our website for additional whitepapers, application notes, etc.

There's a math error at 4:40 if 50dbm came from the source and 10 dbm came back 40 dbm didn't go to the load around 49.5 dbm went to the load

How to find sd11 through this concept

@pauldenisowski

3 жыл бұрын

If you mean S11, please see the video "Understanding S-Parameters"

@kavithasenthilkumar4533

3 жыл бұрын

@@pauldenisowski I am not referring to S11 I am trying to say that when two ports which are connected differential then the S parameter for that is called Sd11 it is not as same as S11 we will get S11,S22,S12,S21 from that we need to find Sd11 that was my doubt if you can help me.please reply.Thank you sir for your reply

@pauldenisowski

3 жыл бұрын

​@@kavithasenthilkumar4533 Differential mode S-parameter measurement is probably a bit too complex of a topic to address in a KZread video comment :) Rohde & Schwarz supports these measurements using our VNAs and we have numerous application notes and presentations on this topic, e.g. cdn.rohde-schwarz.com/pws/dl_downloads/dl_application/application_notes/1ez53/1EZ53_0E.pdf Hope that helps!

✔️💐💐💐🙏

2:39 a yagi with a gain of 12 DECABel? I would expect the good people at R&S to at least use graphics in which the SI units are respected. In this case: 12 dBi.

@pauldenisowski

3 жыл бұрын

Sorry, but could you clarify what you're referring to? I don't believe I ever said anything about antenna gain in units of dB or dBi. The y-axis of the graph at 2:39 was intentionally labelled with the generic unit "impedance" for the purpose of illustrating that impedance is non-constant for most antennas, at least compared to the dummy load on the previous slide A graph of gain for a directional antenna like the yagi shown would usually be a polar plot showing gain in dBi (relative to an isotropic radiator) as a function of azimuth. You are absolutely correct in that the gain of an antenna is almost always given in dBi -- one exception would be something like front-back ratio, which would be in dB, not dBi. Again, my apologies if I'm misunderstanding you. And I can assure you that the good people at R&S are familiar with the different types of dB: in fact, we have an entire educational note on this very topic :) scdn.rohde-schwarz.com/ur/pws/dl_downloads/dl_application/application_notes/1ma98/1MA98_13e_dB_or_not_dB.pdf

@alanmainwaring1830

11 ай бұрын

For a start because decibels is based on log functions there are no units as such in the argument. One can refer to an antenna gain without referring to a theoretical antenna that has a perfect spherical radiation pattern, in practice such an antenna does not exist or you can just use decibels without the isotropic reference. Decibels is based on ratios of things like power, voltage so that the log function argument has no units.

There is an ambiguity, in that the presentation can leave the impression that reflected power gets back into the source and destroys the equipment. This is of course not true. It would be useful to link the rising voltage in the voltage charts to the damage caused to the source device as the explanation of the danger of high SWR. The alternate case of course is very high currents.

@glenmartin2437

Жыл бұрын

The reflected power can damage the finals in radio transmitters. These finals then need to be replaced. Been there and have witnessed this happen.

And what about transmission line? It's not excellent video made by excellent company😒. It's rather support typical misundarstandings according to reflected power.