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Can a VNA directly provide to Z11(it can measure S11) without external processing software?

Rookie

nice presentation. Thanks.

Rookie

Hellow everyone. I come late too bussy.

Rookie

Thanks to all for an interesting presentation.

I have some reading to do.

"

ans:  maybe importing S-parameter into Excel, otherwise I only use real/imag
 
Blogger"
 
 
 
Don't you mean you usually use mag/phase?
Rookie

Thanks everyone. Come back tomorrow for "What Is a VNA & How Does It Work?"

do you find any diffculties with low frenqency part measurement

 

ans:    The coupler in VNA has directivity issues at lower frequencies, so yes we do and I have examples of this in later day of simple validation of low  frequency calibration validation.    Low frequency issues are a large percentage of problems, especially for causality and passivity.

on slide 24, the s2p text file refers to ports S11 S41 S14 S44......are these labels in reference to the DUT ports?

 

ans:  no, they are physical ports of VNA, which was a 4 port VNA.    I defaulted for logical ports = physical ports.   In retrospect I would have named them logically ports 1 and 2.

Would you please clearfy the definitions and difference of spectrum analyzer, vector network analyzer, and vector spectrum analyzer?

 

@John we will ahve these available for viewing.

 

Are these panels telecast or recorded for later viewing?

 

? why you recommend don't use smooth funciton average function

 

ans:  If you use 1kHz IF BW or lower, have a good low noise VNA like ZVA-40 you do not need it, and it masks resonance in systems.   Some VNA's store the touchstone with S-parameter smoothing which creates problems.    You can post process smooth using Matlab very eaisly.   I only smooth group delay btw.   Have a plot of this in day 3 I believe.

EDN collection of articles on S-parameters

http://edn.com/collections/4390332/S-Parameters

BTW, Steve Weir will be a panelist on the SI/EMI panel. There is no escape.

Unless you are good at doing vector math in your head R/I is not that convenient for plotting channel response, or power system responses.  Mag / phase plots are very good for showing views at a glance for wideband systems.

Rookie

Just a quick question, does anyone have a link to a flow diagram as seen on slide 23 that has 4 ports or more? It would help me visualize what I'm measuring better.

Rookie

Just to repeast a question from below:

For SERDES signals with a characteristic impedance of 85 ohms where the single ended impedance could be different from 50 ohms, how do we terminate the unused ports as its impedance may be differnt from the standard available

match of 50 ohms?

You can use a 50-80 T or Pi converter.    Otherwise normalize ports to a different impedance in VNA.   The S-paramter can be normalized to a non-50oihm impedance.

Question from JohnnyFU:

? why you recommend don't use smooth funciton average function

We will also have a panel called "SI and EMI are rleated, get used to it."

 

While we wait a moment for Al, he will be a panelist at a DesginCon panel, "What to do when meausrements and simulations don't match.

DesignCon panel to look at measurements and simulations

Are there certain areas of testing that have advatages using Real/Imaginary or Mag/Phase or is this some historical artifact?

 

ans:  maybe importing S-parameter into Excel, otherwise I only use real/imag
 

Mag phase provide very easy visuals when plotted.  R/I is very good for narrowband RF work

Rookie

Instrument ports should always be terminated into their characteristic impedance.  The idea is to exactly absorb all emitted energy.

Rookie

Are there certain areas of testing that have advatages using Real/Imaginary or Mag/Phase or is this some historical artifact?

Archive version will be available soon, check back.

Rookie

The audio can downloaded?

Rookie

Just to repeast a question from below:

For SERDES signals with a characteristic impedance of 85 ohms where the single ended impedance could be different from 50 ohms, how do we terminate the unused ports as its impedance may be differnt from the standard available

match of 50 ohms?

Slide 24 refers to instrument ports  The reference plane, ie effective position of the instrument ports are typically mathematically moved to the DUT.

 

Rookie

Thanks - see you tomorrow.

Rookie

@tom it will be recorded.

Thank you Al and Wild River

 

Rookie

Can this presentation be re-played?

Rookie

Good morning from California!

Rookie

on slide 24, the s2p text file refers to ports S11 S41 S14 S44......are these labels in reference to the DUT ports?

 

Rookie

For SERDES signals with a characteristic impedance of 85 ohms where the single ended impedance could be different from 50 ohms, how do we terminate the unused ports as its impedance may be differnt from the standard available

match of 50 ohms?

Rookie

Alfred, thank you for today's presentation

Rookie

? why you recommend don't use smooth funciton average function

Rookie

? do you find any diffculties with low frenqency part measurement

 

Rookie

In addition to question on slide 8: Why do you need a sinusoidal source? Is it for adding sinusoidal jitter? Why is it only needed for compliance testing?

Rookie

which page are we on now?

Rookie

Previous webcast, True Differential S-Parameter Measurements

http://techonline.com/electrical-engineers/education-training/webinars/4405822/True-Differential-S-Parameter-Measurements

Martin Eric's article agrees with reality:  S params measure power ratios.  At assumed port impedances that implies voltage ratios.

Rookie

Steve let's talk about that at DesignCon next week.

S-parameter notation explained by Eric Bogatin

http://edn.com/design/test-and-measurement/4389655/Avoid-a-common-S-parameter-problem

S21 is the energy seen at port two from port one.

 

Rookie

S is energy not voltage

 

Rookie

Download slides here

http://downloads.deusm.com/eetimes/EETU/VNA-Manifesto-Jan-20.ppt

Slide 17 See EDN article Avoid a common S-parameter problem that exaplins port notation.

Slide 17. There's no screen. Please download Slide and follow the audio

Cant see your screen

 

Rookie

EDN has a collection of Singal-integrity articles.

http://edn.com/collections/4390774/Signal-Integrity-collection

Slide 8: Why do you need a sinusoidal source? Is it for adding sinusoidal jitter?

which page are we on now?

Rookie

Al, what is the difference between a solver, a simulator, and an SI Model?

Seems to be working now.  I clicked on the red bar several times to rewind and let the player build up the buffer.

Rookie

Re: "try a different browser" - the issue w/audio problems may actually be the flash plugin version & not necessarily the browser.

Rookie

 

Audio is constant and of good quality for me.

I think we are on slide6

try switching browsers.  I'm in FF and it is perfect

Rookie

Chrome provides better audio quality specially on EE Times Course

Sounds good here. Is audio breaking up?

Audio drops out every minute or two. 

 

Rookie

If no audio or poor audio, try chrome. Chrome always provides better sounds than IE

maybe try switching browsers to FF or Chrome seem to work best

Rookie

sounds perfect for me

 

Rookie

The Audio is very poor!

Rookie

Anyone else experiencing audio dropout?

Rookie

Folks designing hardware we will all depend on not understanding signal integrity is a scary scary thing.

Rookie

HW: get used to it :-)

 

 

The audio presentation is running now

 

yes, you may need to refresh.

Rookie

Would you please clearfy the definitions and difference of spectrum analyzer, vector network analyzer, and vector spectrum analyzer?

I can hear the sample, has the presentation started yet?

Rookie

Greetings everyone. Post questions here. Al will join in at the end of he presentation.

 

scroll up, you should see the audio  bar

you might need to refresh

Rookie

Hello from Chicago, IL - iMagine-it-Tech  - (www.imagine-it-tech.com)

 

Rookie

where is the link for the audio then??

 

 

Rookie

Greeetings from Scottsdale

 

Rookie

yes, above  Al's headsheot

 

Rookie

here on the same page??

Rookie

Hello from snowy Vermont

 

Rookie

You may need to refresh the page for it to appear, and then hit the play button on the player

 

Rookie

The audio stream will appear at Noon

Rookie

how can i join?

I can't find the link for audio

Rookie

 

hello from Mishawaka

 

Hello from New Jersey

Rookie

The streaming audio player will appear on this web page when the show starts at 12:00 pm  Eastern today. Note however that some companies block live audio streams. If when the show starts you don't hear any audio, try refreshing your browser.

Rookie

Hello from Chilly Boston!

Rookie

I read the document and I found that I must be focused to follow the course.

Hi i m vishal from india
Rookie

Dear Alfred

This course is at 03H00 Brisbane AEST. Is there a web-on-demand version of this course because I am very interested in attending the entire series.

Deryck

 

Rookie

The course will start at 4am my local time. I hope I can use my home computer to do the work.

Rookie

Hi, This class will add some more education in my portfolio.

Rookie

Alfred,

I look forward to your presentation Monday!

Thanks,

 

Rickey Horwitz

 

Rookie

Can we take s11 parameter from -9.5 dB

 

Is there any certificate of attendance for this course?
Rookie


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