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HFSS Poles/Zeros or Partial Fraction Expansion

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Member level 2
Jun 7, 2010
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Hi all,

Does anyone know a way to plot poles and zeros?

I am trying to create a 3d(if possible) map of a filters poles/zeros, but I am pretty much at a loss. I know there is an export for Partial Fraction Expansion, but I don't know how to use that in Matlab and my matlab does not have the signal processing toolbox (or any other toolbox)

matlab can easily plot 3dimentional graphic. i suggest you to use "fnplt" for this matter

Fnplt might work, assuming I can figure out the .m file that HFSS produces when I use "Export Partial Fraction", but I do not have toolboxes available to me. No Curve Fitting Toolbox == no fnplt

why you intend use toolbox?if you parametric analysis your project(including pole/zero) you can plot them
if you want i attach an example code.....

I took a quick look at the code and see that you also use fnplt along with csaps. Both of these functions are not available to me, but thank you.

I can understand what you have done, but can you briefly describe how you got your data? What is your y[-40:20], x[60:10:120]? And how did you get the yH coefficiants?

why fnplt and csaps are not available for you?
these data are the output of HFSS, the graph is somewhat rough. if you intend plot a picture smooth you must increase the data result. x and Y were the antenna parametric (in my thesis).

Fnplt and csaps are in the Curve Fitting toolbox. I dont have that.

I am still not sure how you came up with your data. I opened the HFSS matrix data and used the Export Equivalent Circuit>Partial Fraction Expansion for matlab and this is what I got.


  • Diplexer_Filter_pfe.txt
    2.3 KB · Views: 92
  • Diplexer_Filter_pfe_sol.txt
    4.9 KB · Views: 92

perhaps fnplt is in toolbx but i never use it in toobox. u can write m-file
in view of secena attachement i didnt see plot command, you just collect data
i propose u can image real part is X and imaginary part is Y, then plot them at some frequency versu magnitude

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