Smith Charts plotting in LabVIEW

[arwc]

Hi,

I am trying to plot a smith chart in LabVIEW using the picture plot vi, but is not formatted to accept the data type that I have. I have saved s11 data, so I have phase and frequency data. The smith chart vi calls for r and x. Is there an example for plotting a smith chart given s11 data and not r and x data (aka how to plot the smith chart in polar form)?

Thanks!

[Gregory]

This doesn't directly answer your question, but the Advanced Plotting Toolkit is supposed to greatly enhance your plotting capabilities:

http://advancedplotting.github.io/

[REAL!]

Hi,

Do you mean S11 as in S-Parameter measurements from RF testing?

If so then my (limited) knowledge of RF would assume that the S11 is made up of an complex number (such as 2.3+i34) which is an amplitude and phase so can be converted to any other relevant format.

If you are not doing S-Parameters then feel free to forget what I just wrote...

Hope that points you somewhere in the right direction.

Cheers,

Darren.

[arwc]

Yes, I am referring to S-parameters & Yes, they are in a complex format. I think I just need to grind out the math and convert the values to real and imaginary impedance values, which labview will accept to make a smith plot... It will be annoying, but I think that is the only way to do it.

[Ben]

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@arwc wrote:

... grind out the math and convert the values to real and imaginary impedance values, which labview will accept to make a smith plot... It will be annoying, but I think that is the only way to do it.

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Have you looked at the Complex sub-palette under numerics?

Ben

[arwc]

Ben,

Yes, they are really helpful!

Thanks.

[arwc]

Hi,

I am still working on the smith plot business and now I've run into another problem... The error I have now is "These cannot be wired together because their data types (numeric, string, array, cluster, etc.) do not match. Show the Context Help window to see what data type is required. The type of the source is cluster of 2 elements. The type of the sink is 1D array of cluster of 2 elements." I formatted my code just like the example and I still have this error. I have posted my code (just where the error occurs) and the example vi for smith plotting. Please and thank you for your help!!!

[REAL!]

Hi,

In the picture without the broken wire you have an array of 5 clusters (created by the for loop) but in the one with the broken wire you have a single cluster.

As they are just pictures I cannot check for the functionality, but this is why you have a broken wire.

Cheers,

Darren.

[REAL!]

Also...

From what I remember if you just provide one cluster of data (amplitude and phase) you will plot a single data point. If you want to plot a line, you will need 2 clusters.

Use the properties to make the points bigger, otherwise a single point is very difficult to see.

Cheers,

Darren.