Understanding S Parameters

Radio frequency networks are characterized using S (scattering) parameters, and this video provides an easy introduction to S parameters and how they are used to quantify impedance matching and power transfer in radio frequency networks.
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[@joelgray3571]

This video has taught me more about s-parameters than my comms class has - 4th year engineering student. Keep making videos like these please!!! Brilliant stuff!!

[@pauldenisowski]

Thanks! And there is much more content coming, so please stay tuned!

[@airsoft78910]

It is remarkable that no one explained this before in the program I am doing, these 10 minutes brought so much knowledge together for me. Thank you.

[@pauldenisowski]

Yes, unfortunately there often isn't the time in modern engineering courses to explain these kinds of practical, test and measurement related topics, which is one of the reasons why we make these videos and other content :)

[@danny_racho]

@@pauldenisowski Thank you for this. Do you plan on doing a video, where you also show how the calculated S-parameters would be needed in testing or for a system? I learned how to calculate them, but I see no practical use for these kind of information. Maybe a test setup with network analyzer and/or matching network in the process :)

[@pauldenisowski]

@@danny_racho Thanks! Actually, I'm looking into that topic right now :)

[@CoversTavo]

Thanks for the simplicity.. I needed to remember because I saw S parameters in one engineering course but I forgot everything. this video refreshed my memory.

[@arts9591]

Amazing Explanation - So much needed in the real word.

[@isr1825]

Great video Sir, such a clear explanation! Thank you very much.

[@dianarune9704]

You have saved me on the night before my exam. I love you forever.

[@selvakumarr6672]

Perfect video to understand S-parameters. Thanks to the team.

[@user-lt5no1xt1z]

thamizh?

[@jacobrandall4891]

This channel will be very helpful for reference when I get into Grad school. I hope I can work for Rohde Schwarz one day!

[@christophschwipps8670]

Excellent video - brief and precise. Thanks a lot.

[@egbertgroot2737]

Superb video!!!!! Thanks. Now i can use my VNA menu S-parameters!

[@balajienterprises7294]

Great video Sir, such a clear explanation! Thank

[@sehnsuchtsora4301]

Thanks Sir, helps a lot since I'm not even an amateur.

[@mattanova]

Brief and very informative, thank you so much

[@danielnaicker2142]

Extremely helpful video, Thank you so much!

[@bloguetronica]

This was extremely valuable and very well explained. Thanks for sharing!

[@ariefhadipratamagultom6759]

Thanks for the explanation

[@jessicagonsalves4137]

This video was just amazing! Thank you very much :))

[@chrisscott1547]

Well done! Now onto converting the various units...

[@gerrick_3362]

thank you so much. super helpful!

[@sulaimangari2745]

Thanks for the great video

[@pavan5140]

Very well explained

[@alim6583]

Thanks for efforts 👌

[@MrVishalbharti]

Thank you for the explanation about S-parameters. Superb

[@pauldenisowski]

Thanks for the feedback!

[@josephgithinji3530]

thank you for this Sir awesome

[@NT4XT]

Thanks!

[@goodtogo2626]

Nice buddy... Thankx a lot for such a great concept explanation

[@pauldenisowski]

Thanks!

[@zaidinajah8741]

That will save my neck,,, Thank you

[@pauldenisowski]

Glad it helped!

[@GustavoSimas]

Great video :)

[@KeritechElectronics]

A very simple and clear explanation, none of that complex numbers rubbish! (just kidding, advanced maths will definitely come in handy here, but it can be daunting) :)

[@pauldenisowski]

Thanks! I try to avoid math whenever I can - there are plenty of other resources for people who want to work the numbers :

[@bandaruramana2119]

It's highly rare video found in you tube and it's useful for me and can you explain me how positive and negative cycle flows in radio frequency with in conductor

[@pramodpramodsingh9966]

nice video

[@dipankarsinha6565]

very good teaching

[@pauldenisowski]

Thanks!

[@bobowzki]

Very good

[@helmutalexanderrubiowilson6835]

flawless!!! im subscribed

[@pauldenisowski]

There's much more on the way in the next few weeks, so please stay tuned!

[@ahmednor5806]

🙏🌹

[@dawwin2115]

Thank you so much for your very good explanation 😊😊😊

[@clarkrichardson5846]

👌🏾

[@damarouthuyesubabu3484]

Gud sir

[@ahemednor5201]

🙏🙏🌹🌹

[@forresterickson6225]

Please put a link to the VSWR and Return Loss presentation video in the information above. A link to an introduction to Smith Charts too.

[@forresterickson6225]

Found the Smith Chart presentation at: kzbin.info/www/bejne/qIanfqJtndycntU

[@richardphillips2405]

Thank you so much. This is the best explanation I have seen. I was wondering how S-parameters are expressed in a matrix as a complex value. Would it be expressed as a trig. function such as real, imaginary value or polar?

[@RohdeundSchwarz]

Dear Richard, they can be expressed either as a magnitude and phase (polar) or as real and imaginary parts. S-parameters are usually stored in the Touchstone file format, and this format supports both representations (e.g. “magS11 and angS11” or “reS11 and imS11”). Best, Rohde & Schwarz Social Media Team

[@richardphillips2405]

@@RohdeundSchwarz What is Touchstone file format, magS11, angS11, reS11, and imS11? This is new to me. I got interested in this when I purchased a Nanovna and I am wanting to learn more about this subject. Again, I appreciate your KZbin video on S parameters.

[@pauldenisowski]

@@richardphillips2405 Most network analyzers can store measured S-parameters in a standard file format called the "Touchstone" format. This allows for easy export and input of S-parameters, even between different instrument types and manufacturers. S-parameters are complex values which can be represented as either a mangnitude + phase (angle), or as a real part + imaginary part. The Touchstone file format specification allows you to use either representation. A simple S11 Touchstone file contains three columns of data: frequency, and then either real and imaginary values (ReS11, ImS11) or magnitude and angle values (MagS11, AngS11). Touchstone files usually have an extension .snp, where n is the number of ports. So a file containing the S-parameter data for an S11 measurement normally has the extension .s1p. Incidentally, you can save S-parameter data from the NanoVNA in Touchstone format using the NanoVNASaver tool.

[@sivasankars6218]

@@pauldenisowski When downloading capacitor s-parameter, there are 2 files that series and shunt available. Which and where and when I need to use those?

[@user-mo1dh1xf2k]

the thunderstorm parameter in the village at the master's exit center is linked to the object above night

[@pauldenisowski]

'Twas brillig, and the slithy toves did gyre and gimble in the wabe

[@muhammadrofiqfajarsetiawan2131]

Hi sir, my name is Fajar I have a question. When I use network analyzer to measuring antenna, the return loss values is positive. But why return loss value I mean S11 on CST microwave studio is negative? If S11 always have a negative value, so how I can find the return loss with positive value on CST? Or you have another explanation for this case? Thanks

[@pauldenisowski]

Hi Fajar - I don't work with CST Microwave Studio, but I think the issue might be that many people incorrectly use the term "return loss." The editor-in-chief of IEEE Transactions on Antennas and Propagation published an excellent two page article called "Definition and Misuse of Return Loss," in part because close to a third of the people submitting papers to this journal (!!!) were using the term "return loss" 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. However, frequently this term is confused with a reflection coefficient that has been expressed in dB. The logarithm is taken of the magnitude of the reflection coefficient, but this is incorrectly referred to as return loss; the result is still reflection coefficient, albeit in decibels. The difference between the two is a minus sign" "it is common place to see plots captioned and labelled return loss when, in fact, they are really describing reflection coefficient. I have even had some reviewers asking authors to change the correct form to the incorrect form, i.e., to change a positive sign to a negative sign, even though the authors labelled the plot correctly as return loss!" So I assume this is the reason you're seeing negative "return loss" values in CST Microwave Studio. Hope that helps :) ieeexplore.ieee.org/document/5162049?arnumber=5162049

[@jb3757]

I think you should've mentioned the names of the instruments shown in the video, I found it a bit hard to find the model number of the exact VNA instrument shown in the video.

[@pauldenisowski]

That's intentional: in my "technology" videos I try to avoid making references to specific products since these are always changing. We (R&S) support S-parameter measurements on all of our VNAs. In fact, I think it would be hard to sell a VNA that didn't do, at the bare minimum, S-parameter measurements.

[@jb3757]

@@pauldenisowski True.

[@ratoshkouria8967]

Good morning sir Please I'm working on antenna project and I want a Sparameters for RF flilter and I don't know how can I write it Could you help me or upload it Thanks a lot..!!!

[@pauldenisowski]

Normally you would obtain the S parameters for a filter by making an S21 measurement with a VNA. You might also be able to get those parameters from the manufacturer in Touchstone file format (.s2p).

[@spysine4086]

how to use s-parameters and get impedance depending on frequency, pls

[@pauldenisowski]

S-parameters are measured with a vector network analyzer (VNA), which injects RF energy into one port and measures the RF energy that is returned from that port and/or which appears at the other ports. This is typically done over a range of frequencies, and the complex impedance values are provided by the instrument. There are both professional and hobbyist VNAs available that can measure and provide S-parameter values for at attached device under test (DUT).

[@spysine4086]

Paul Denisowski Hey again:) thx for ur reply. I know what u mean. But my question is different and now I will try to explain to you. In touchstone file .s2p we have f value, angle value(gamma) on each of the s-parameters (s11,s21,s12,s22). And my question is “how to convert this angles to z impedance” when i take datasheet of any transistor , i have impedance values at some frequencies, but i want to know values on different freq and use s-parameters. Maybe u know how to matching(load pull) transistor without vendor model(design kit), pls make me understand Take this site as an example www.leleivre.com/rf_gammatoz.html

[@pauldenisowski]

​@@spysine4086 If you need to know impedance values (or S-parameters) at certain frequencies or if you want to do matching, the best solution is to make measurements using a VNA :) You might want to ask this question on a site like eevblog since it's a bit too involved to answer in the Comments section of this video. Good luck!

[@clems6989]

in the graphic @1:00. where is the DUT inserted ?

[@pauldenisowski]

The DUT is the box itself -- the VNA is connected to the three ports. An example of a 3 port device would be something like a splitter or directional coupler.

[@labnotes23]

@@pauldenisowski exactly...

[@youtubevideos1248]

Why is first subscript the output port and the second subscript is the input port? It seems counterintuitive.

[@AlbertRei3424]

It helps with matrices calculation

[@ahmedtarek9801]

pls give me some application about measuring scattering parameters

[@pauldenisowski]

The vast majority of basic network analyzer measurements are S-parameter measurements. An example of an S11 measurement is measuring an antenna: ideally we want an antenna that is "matched" to the source impedance and returns / reflects the minimum amount of transmitted energy at the given frequency. An example of an S21 measurement is measuring a filter, where we are interested in things like the filter passband (the frequency range over which it passes signals), the amount of out-of-band rejection (how much signals outside of the passband are attenuated compared to signals within the passband), and the shape of the filter (how steep the "skirts" of the filter are).

[@ahmedtarek9801]

what is the concept of operation of measuring scattering parameter

[@pauldenisowski]

@@ahmedtarek9801 S-parameters are normally measured using an instrument called a network analyzer, which injects RF into one port of a network (usually over a range of frequencies) and measures the amount of power reflected back from that port and the amount of power appearing at any other ports.

[@43SunSon]

pika pika!

[@Stone218]

Now, update Chinese (Taiwan) sub-title. 中文(台灣)

[@pauldenisowski]

我們將盡力而為 :)

[@pauldenisowski]

Thanks for the subtitles!

[@Stone218]

Paul Denisowski welcome,we will do more Chinese subtitle !

[@pauldenisowski]

@@Stone218 I'm very much looking forward to it. 謝謝!

[@sethrollins5454]

原來就是大哥添加的中文字幕 真的太感謝了

[@user-cn2tk9mg3e]

Thanks for sharing! is it possible to get the PPT？

[@skorpionhades2177]

Dieslike

[@williambudd2850]

Bla, bla,bla. I am a college educated electrical engineer and I had never heard of s parameters or what they stood for. It sounds like something dreamed up by a math major that because they don’t really describe what they mean will never catch on. Good luck with that one.

[@pauldenisowski]

(laughs) That's how I feel about them some days as well :) Actually, they are very useful in RF, but not really used (as far as I know) in any other EE disciplines. I have an MSEE from NC State and I'm not sure I ever had anyone explain S-parameters to me either, hence the video :)

[@1412dante]

S - parameter is all about signals and very useful in RF world, and also the Smith Chart. It is the thing that makes difference between EE RF major and the rest EE major.