Automatic selection of element values of antennas impedance models

Hello everybody!
How can I interpolate my experimental curve using an electronic circuit? I want to make impedance antenna model of simulated impedance of my antenna.
I wrote equations to get the impedance of the Foster?s 3nd circute and made interpolation with Matlab curve fitting, but result isn't good.
Now i want to realize K6OIK?s Broadband Equivalent Circuit from (open access) and matlab curvy fitting can not manage it.
Anyone knows how can i solve this problem?

Seems using a FEM frontend is by far quickest means to do this, for instance COMSOL provides you with a means to input an antenna and from there you can modify its parameters including physical properties to have it achieve the objects which you computed. You would however need to provide solidmodels of your antenna.

Thanks so much for help!
Do you know how to get the values of the elements of a certain ircuit according to the S-parameters(ASCII)? For example, presented in the application circuit.