S-Parameters Explained Part One | Signal Integrity

[@myetis1990]

when watching Zach's videos ,I feel like I'm collecting bonuses in a video game inspecting a filters characteristics in terms of s params would be very appreciated.thank you very much. keep up good work

[@Zachariah-Peterson]

Stay tuned for a demo with a VNA, as soon as my SMA connectors for my test board arrive in the mail I will start working on it.

[@jonastjepkema]

This is so good!! Thank you so much

[@yetao501]

This is by far the best explanation of the concept of S-parameter. Many thanks!

[@AltiumAcademy]

Glad you think so!

[@mikhaildavydov2198]

That's the real treasure! Thank you a lot Zach!

[@rezakohandel6077]

amazing explanation Zach, thanks.

[@ehsanbahrani8936]

Thank you so much ❤

[@doktortronikelektronikaszk4070]

Worth to remember that this black box (DUT) should be a linear circuit (small signal stimulation) in steady state to use s-parameters for analysis.

[@Zachariah-Peterson]

Yes LTI circuits only, although there is a variant called X-parameters for time-invariant nonlinear circuits.

[@erikchen8897]

great video. very helpful

[@carloseduardomayerdeolivei2913]

Thanks Zach!

[@janstoeb]

As a student I found S-Parameters very confusing, since S-parameter theory is often misunderstood and therefore largely incorrectly explained, even in my university lectures. The most common and relevant S-Parameter formulation in my eyes are the generalized S-parameter, as they are used by basically all simulation tools (AWR Microwave Office, Keysight ADS, and so on). They are based on Kurokawas "Power Waves and the Scattering Matrix" from 1965. If you take a look into this theory of Kurokawas Power Waves, you will find, that in your definition of the reflected power waves b (which are actually just square root power waves) there is a missing conjugate complex. Furthermore, the a-waves are not the power injected into the network, but always just the "exchangeable" power (maximum power which could be injected into the network from a source of impedance Zref). One reason for a lot of confusion is the close relationship between power waves and travelling waves, the latter which are basically voltage (/EM) waves as they appear in transmission line theory, where the term reflection coefficient is also an important subject. Explanations of S-Parameters and generalized Parameters can also be found in the books of Collins and Pozar.

[@manojaa8338]

As usual great explanation...you always educating us from basics

[@AltiumAcademy]

Glad to hear that

[@SIAT2023]

thank you so much for this video . could you please show me theoretically , mathematically and practically how S11 value will effect on E-field (when will be strong E-field or week ) if we have multi resonance at different frequencies with s11= -60 dB , -45 dB, -15 dB ,

[@pushbaner5219]

Sometimes I get confused whether I am viewing athleanx or altium 😅 either way happy learning

[@jagadishk4513]

"Parasitic resistance is killing your gains"

[@lolsypussy]

He's a successful musician now. kzbin.info/www/bejne/p6apg5h-faaAgK8

[@dineomogapi4093]

Wow i really like how you explained this,😯

[@Zachariah-Peterson]

Thank you, glad it was helpful

[@simoudkahina6253]

Thank you that was really useful

[@AltiumAcademy]

Glad it helped

[@sajidmaqsood3984]

very well explained

[@AltiumAcademy]

Glad you think so!

[@SIAT2023]

and i need your confirmation about absorbed power and reflected power concept [ is correct or not? ]and please if not show me the correct one (as you said An S11 value of -100 dB indicates extremely good matching, ...........that meaning almost all the incident power is absorbed by the device and very little is reflected back.so the E-field at this situation will be very strong right? because the maximum power absorbed by DUT which will generate strong E-field right?) and vise versa when S11= -30 dB THE e-field field will be good but not more than -100 righ?

[@GaziSharif]

Amazing explanation. Thank you. Could you please tell how to extract component values (R, C, L) of the equivalent circuit from measured S parameter from network analyzer?

[@Zachariah-Peterson]

We just filmed a video about this topic, and I created an excel sheet that shows an example for a transmission line. It should be uploaded soon and I'll make the excel sheet available to download.

[@GaziSharif]

@@Zachariah-Peterson Thank you so much.

[@googlesucks1376]

What about Z parameters, or Y parameters. Maybe even ABCD parameters. Or H or T... Best to get a copy of Chris Bowick's book "RF Circuit Design" He discusses Y and S in some great detail. The wiki page on two-port is another great source of info on various signal parameters and their uses.

[@Zachariah-Peterson]

Definitely good points! That stuff is covered in part 2 of this video. I'll also do a little example later with a VNA that shows how you can convert the data into those other parameters.

[@googlesucks1376]

@@Zachariah-Peterson If you could, maybe use a low-cost VNA like the Nano so people on lower budgets can follow along

[@Zachariah-Peterson]

@@googlesucks1376 I'm going to use a Libre VNA

[@googlesucks1376]

That's be easier to get screenshots with. I did note the disclaimer on one website (which is true with any low cost unit): "Due to this being an open source VNA, there are some limitations in the design. These remarks are as follows: Due to some structural limitations the S12 isolation is 10 dB worse than that of the S21 parameter. Above 3GHz the performance decreases with increasing frequency causing the port isolation to only be 50 dB at 6 GHz. Furthermore, below 1 MHz, the performance decreases with decreasing frequency and the effective dynamic range decreases to 70 dB at 100 kHz. The output power may decrease when frequency is lower than 1 MHz or higher than 3 GHz."

[@優さん-n7m]

I still do not understand why the diagram does not actually represent a typical 2-port block diagram where there will be signals on the lower terminals as well. Why is this?

[@Zachariah-Peterson]

The lower terminal is not supposed to represent a port where a signal can enter, it's just supposed to represent your ground reference. Some guides will use the lower port to denote only the reflected signals, but then a 2-port network would have 4 ports drawn on it, so it gets confusing. If you think about it in terms of the signal and its refernece representing the port together, then I think the block diagram makes more sense.

[@svc761manikandank3]

Hiii sir... What is the difference between delay tune and serpentine rule

[@Zachariah-Peterson]

I'm not sure what you mean by a "serpentine rule", are you referring to the routing structure you would use for delay tuning?

[@優さん-n7m]

When I first came across S parameter, I thought this was the S from Laplace Transform but then I realized that it is not.

[@saeidesekhavati1518]

😍😍😍

[@pranavchaitanya6283]

OMG!!!!!!!!!!!!!!!!!!!!!!1

[@ZatoichiRCS]

Horrible explanation. Yes, let’s jump across the math.