Fitting an equivalent circuit in EIS data (Frequency, Re Impedance, Im Impedance)

I have a set of data (Freq, Re Z, Im Z), that came from EIS measurements. Is there any tool or function in matlab that I can use to find the parameters of an equivalent circuit for this data set?

Thank you!

Answer 1

[Star Strider]

You indicated the Signal Processing Toolbox, so in that regard, see if the invfreqz function will do what you want.

Beyond that, the idfrd function in the System Identification Toolbox would likely be appropriate. If you have the SIT, start there and follow the links.

Those functions will identify the parameters, however it will be necessary to use circuit synthesis techniques (Foster or Cauer or other approaches) to actually build an equivalent active or passive circuit from them. That is definitely not trivial.

[Panagiotis Artemiou]

Thank you very much for your answear. I will try apply what you suggested.

[Star Strider]

My pleasure!