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How to make a Smith chart

johndcook.com

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Re: How to make a Smith chart

#31

Post by buescher »

hammock wrote: post #10

Is this related to Cardioid patterns for directional microphones?

No. The RF equivalent of that would be an antenna pattern. The smith chart is a particular mapping of complex impedance that allows for fairly straightforward calculation and visualization of things like conjugate matches. It's related to the impedance plots for speakers, but audio engineers generally don't use it. RF engineers will plot impedance vs frequency on it though. If you come across curlicue plots on it, those are typically frequency sweeps i.e. they plot impedance vs frequency. You might have to look for the frequency legend or endpoints.

Re: How to make a Smith chart

#32

Post by araes »

kazinator wrote: post #12

This animation is helpful: https://en.wikipedia.org/wiki/Smith_chart#/media/File:Animat...

Not knowing enough about Smith Charts, do the intermediary frames have any meaning in terms of actual practical problems or calculations?

It seems like the chart itself would be a member of an entire family of chart types that would go through the entire 3D rotation with several versions that were "nearly tangent circles" and eventually concentric circles at the center of the graph, along with some of the intermediary frames shown in the animation.

Re: How to make a Smith chart

#33

Post by kazinator »

araes wrote: post #32
kazinator wrote: post #12

This animation is helpful: https://en.wikipedia.org/wiki/Smith_chart#/media/File:Animat...

Not knowing enough about Smith Charts, do the intermediary frames have any meaning in terms of actual practical problems or calculations? It seems like the chart itself would be a member of an entire family of chart types that would go through the entire 3D rotation with several versions that were "nearly tangent circles" and eventually concentric circles at the center of the graph, along with some of the intermediar…

The intermediary frames have an interpretation as being congruent to a scaling. Near the outset of the animation when the imaginary axis slightly bends, it has already become a circle. So it is congruent to a large Smith chart.

Re: How to make a Smith chart

#34

Post by seoulbigchris »

btkramer9 wrote: post #2

I loved smith charts during my microwave classes in college. I've always felt like there should be a fun game based on the mechanics of using a smith chart.

I felt the same way. At some point shortly after graduation, I found a heavy plastic Smith chart that was designed to be written on with a grease pencil, and erased with a cloth when you're done.

Re: How to make a Smith chart

#35

Post by seoulbigchris »

btkramer9 wrote: post #2

I loved smith charts during my microwave classes in college. I've always felt like there should be a fun game based on the mechanics of using a smith chart.

Oh, found a picture of one of these plastic ones flikr:

https://www.flickr.com/photos/jonsphotos/218609214/in/album-...

Re: How to make a Smith chart

#36

Post by seoulbigchris »

btkramer9 wrote: post #2

I loved smith charts during my microwave classes in college. I've always felt like there should be a fun game based on the mechanics of using a smith chart.

If you liked the Smith Chart, you'd love using the Spirule to solve root locus problems.

https://en.wikipedia.org/wiki/Root_locus_analysis

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