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Very interesting but also complex!

Good presentation

Rookie

had some doubt in slide 11

Rookie

good one for all the beginners to SI

 

Rookie

How expensive is SI Lab? To start and to maintain the SI lab for about one year?

Rookie

It does'nt look like it is live class

Rookie

How this online chat works, please explain

 

Rookie

How to locate impedance mismatch using S11 parameters

Rookie

Hello Sir,

Just to confirm if I am online. Please confirm

Rookie

A Signal Integrity lab must have the tools to measure, simulate, and validate.    If the capitol to purchase VNA is not avaiailable you can rent a VNA, you can other 3rd parties make measurements for you for fee.

 

No, the difference between the nulls, OR the peaks (not null to peak) is frequency of resonance difference.

 

1/2TD equals resonance difference.   Ok?

Thank you everyone. See you tomorrow and I look forward to meeting you next week at DesignCon.

As you sing, I asked new scope to my boss but he refused!

You need or shoud want at least NyquistX5.

So 5Gbpsec is 2.5GHz Nyquist, and 5X is 10GHz.   I would consider a 20GHz VNA as a good investment.

 

Al play guitar too. He's probably better.

wonoh.kim hes that's me

Martin:  Did you post this video on youtube yet?  :)

Another question that came up earlier.

Usually I use 50 Ohm or 100 Ohm terminal to mach impedance. I wonder where the number 50 or 100 ohm come from? Is it impedance of (RF) path (AFE) or impedance from driver end?

You are the gentleman with guitar?

A previous question you can see it below but I copy it here.

is the distance between the null and peak the value "td"

Copying obarrett back to the top of the list for AL to see.

My 2-port DUT has female N connectors, the two patch cables from my VNA ports and the 3 ports on my VNA calibration tee have N-Male connectors.  Doing my SOLT calibration, I install female-female barrels on the calibration tee, and use another barrel to join the patch cables for the Thru calibration.  Should I still enter the reference plane corrections into the VNA for best accuracy?

 

Answer:   There are 2 options, ignore the adapter if you do not need pristine return loss and can delal with delay, or do Adapter Characterization, another option is to simply include the connector in the calibration.

A 3rd option that works ok is to use simple Port Extension, where the adapters are often 50psec approx length.

Cool. MeasurementBlues. You are a song writer. May I have your sign ;)

I'm currently working on detection of PIM (Passive Intermodulation). Does anyone have experience on PIM?

wonoh.kim I am Martin Rowe. I use the name MeasureMentBlues because I wrote a song called The Measurement Blues. I'll send a link.

(ref my question) " for measurements at short wavelengths".

Rookie

I agree with you cuong. Yet somtimes, it's easy to simulate than test. 

At previous company, I used to use VNA. I am pursuading my boss to setup RF lab (with VSG and VSA)

Wonoh:  Remember that despite ANY features in ANY simulation tools (your $1K MATLAB, etc..) the results are only as good as the models used in the setup.

Nope - I have a personal analog Network analyzer but no VNA.

Rookie

Copying obarrett back to the top of the list for AL to see.

My 2-port DUT has female N connectors, the two patch cables from my VNA ports and the 3 ports on my VNA calibration tee have N-Male connectors.  Doing my SOLT calibration, I install female-female barrels on the calibration tee, and use another barrel to join the patch cables for the Thru calibration.  Should I still enter the reference plane corrections into the VNA for best accuracy?

thanks!

@MeasurementBlues, who are you ask the question?

Does anyoine have VNA in the lab? have you use it?

I have some Matlab code programmed by myself but tired to program all of them by myself.

@Wonoh, Let your boss buy? More like Make Your Boss Buy!

Matlab used to have user codes of RF toolbox. In fact many of toolbox is contributed by users. 

I am studying a trifecta of VNA

Keep up the good work

Have a good day, and good evening all.

Rookie

No. Octave has no RF toolbox. That's the reason I asked user code

While we wait for AL, here is a link to an article about VNA calibration

http://edn.com/electronics-blogs/all-things-measured/4421792/Be-confident-in-VNA-measurements

If we are playing with lower frequency/lower data rates, going to 40 GHz can be overkill. What are the alternatives for lower frequencies?

Rookie

I should let my manager listen this class and buy me Matlab toolbox ;)

Does GNU Octave have an RF toolbox -- anyone?

Rookie

My 2-port DUT has female N connectors, the two patch cables from my VNA ports and the 3 ports on my VNA calibration tee have N-Male connectors.  Doing my SOLT calibration, I install female-female barrels on the calibration tee, and use another barrel to join the patch cables for the Thru calibration.  Should I still enter the reference plane corrections into the VNA for best accuracy?

thanks!

Rookie

I'm not saying simulation will replace bench measurements but people should not go straight to bench w/o simulations...  Life is tough either way!  :)

cuong typical practice requires designing and verifying process test vehicles first.

Rookie

I should record and play to my manager ;)

I agree you need both...  however, measuring is AFTER the fact... and can be costly for re-fabbing boards

Alfred, thank you for today's lecture

Rookie

which is the best cal kit? 

Rookie

hi, all VNA Need a cal kit? 

Rookie

Wonoh:  There are definite advantages in simulations before fabbing/making those expensive boards.

Slide 30 Benchmarking Time Domain- VNA, TDR, 3D EM Field Solver

Since VNA can be cost prohibitive, many people resort to simulation tools.  What are your recommendation (not from what tool or vendor to buy) but acceptable tolerances compared to bench measurements (ie. correlation to bench), features, etc?  That is, what are the things to look for if one wants to buy EDA SW simulation tools for frequency-domain work?  (I understand you mentioned MATLAB with RF Tool box). 

slide 29 How much VNA bandwidth do I need for a desired time domain

 

With this level of concern for cleanliness, why not use cleanroom white gloves?

 

Welcome jlin we are on slide 21

al@wlidrivertech.com it's on the last page of your slides.

Matlab Toolbox is expensive. Is there any site to get a free version of RF Toolbox coded by users?

I came in late.  Please tell us the email address of the presenter.  He invited us to write him.

 

Rookie

sorry, the question about "td" refers to slide 14.  He mentioned taking the peak and null from slide 13 and using that number on slide 14.  Please explain again.

Rookie

the slide for "td" was 14

 

Rookie

I'm copying the questions and we'll ask Al at the end. Please put the slide number in your question.

 

The distance between peaks or distance between nulls is 1/td

is the distance between the null and peak the value "td"

 

Rookie

Al went back to slide 13

Slide 14: I usually think of resonance as a frequency.

Slide 13 Return Loss Comparison

I couldn't imagine multiple transmission lines. Would you please show us the transmission lines diagram?

Slide 12 Family of Loss for 5GHz and 14GHz Common Nyquist Frequencies

Slide 11 Lets Compare 2 Real Microstrip Traces Test Circuits, One Short One Long

Slide 10 Investigating return loss, S11, S22

Martin lossless follows the (1-s11^2)^0.5

 

Rookie

Slide 7 For a Lossless Case- How Does S11 Impact S21?

Usually I use 50 Ohm or 100 Ohm terminal to mach impedance. I wonder where the number 50 or 100 ohm come from? Is it impedance of (RF) path (AFE) or impedance from driver end?

Slide 6 Relate system Zo to Snn variation

Slide 5 Useful Impedance Relationship

Try to open on chrome or firefox

johnCe try refreshing and hitting play

Rookie

Interpreting S-Parameters Slide 4

Has the course started?  I logged in but there is not audio or video

 

Rookie

Concept of VNA Measurement – Return Loss

If the audio does not work, try refresh the browser bar.

Rookie

Add 31 to the slide #

 

Rookie

 

Audio is clear but I missed the countdown clock

OK - I thought I recognized the similarity with Waukesha (my home town)

Rookie

 

Mishawaka is between Chicago and Detroit

hello from cold and snowy NJ

Rookie

hello from sunny and dry California

Rookie

@john matwyshyn - where is Mishawaka?

 

Rookie

Hello from sunny SE lake Simcoe Ontario Canada. A balmy Spring-like day -24 deg. C

Rookie

 

hello from Mishawaka

 

Hi from clear and sunny Portland OR (unusual for Portlandia)

Rookie

You are correct MeasurementBlues and here I am complaining that is a chilled morning  :)

Rookie

Be confident in VNA measurements by Chris Grachanen. This one is about calibration.

Greetings Jose. I assume it won't be snowing in Scottsdale today.

We posted several comments with links to articles about S-parameter's yesterday.

Greetings from Scottsdale, AZ

Rookie

Made sure you download your slides using the link "Today's Slide Deck" above.

Hmm, the links dont; show up any different that other text. I'll try underlining. Here's mre previous post again.

I start with this blog by Rick Nelson, S-parameters are so yesterday.

Good Morning from so far just Cloudy Boston! 

Rookie

Good morning, afternoon, or evening depending on your location.

Being as today Al will ask What Is a VNA & How Does It Work?, I though I'd get a jump and provide some links to articles wer have about VNAs.

I start with this blog by Rick Nelson, S-parameters are so yesterday.

Good Morning from soon to be snowy Boston

Rookie

Good Morning from North Pole, Alaska

Rookie

Alfred,

I'm attempting a trifecta.  My poor brain is going to burst!

Thanks,

 

Rickey Horwitz

 

Rookie


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