Polynomial equation from the S matrix

Hello friends, I have to get the polynomial equation from the S matrix, for example I have measured the S parameters of the SMA connector using the VNA for the frequency range 300KHz to 4GHz. I have to determine the loss of the connector and get the polynomial equation for the each S parameters such as S11,S12,S21 and S22. How can I get it with this information, could anyone please help me?.
The below figure is the S2P file obtained from the VNA

Loss of connector can be determined directly from Insertion loss information in S12 or S21 but that will be at particular frequency since you have a range of frequency so you will get a trend in loss by observing insertion loss.
To find the polynomial you can use Matlab or even EXCEL that is very easy

could you please tell me how can we find the polynomials with the matlab?. because I have the S2P file, when I tried the poly command it doesn't work out for me.

Try to import it in Excel and then plot the trend it will fit the polynomial of the order of your choice.
I am currently not using Matlab so do not know much about it
Try with Excel if it does not work we will see how to work around this problem