No that's not what I mean
Its just what you do in Time domain reflectometery. Doing this actually you can find how impedance behaves along the line (discontinuties,or any other changes). Here is the code that I wrote (with a colleague's help) to do just that
load C:\Shaf\gen.s11; %load the file which has S11
Spar=gen(:,2:3); % All the rows but 2nd and 3rd columns
Freq=gen(:,1); % All rows but first column
fvec_sim = [0:600e6/2048:600e6-600e6/2048]; % from 0 to 600MHz, 2048 points
number_rows=size(Spar); %
number_rows=number_rows(1,1); % number of rows
for i=1:1:number_rows % turning them into proper imaginary notation
Spar_procd(i,1)=Spar(i,1)+j*Spar(i,2);
end
fdelta = fvec_sim(2)-fvec_sim(1);
fsim = max(fvec_sim)+fdelta;
tsim = 1/fsim; % tsim is step in time.
time = [0:tsim:1/fdelta-tsim];
s11 = interp1(Freq,Spar_procd,fvec_sim,'linear','extrap');
s11_windowed = s11.*(1 + cos(pi*fvec_sim/fsim))/2;
t11 = ifft(s11_windowed);
impedance = 50*(1+t11)./(1-t11); % Zo is 50
tdr = impedance;
c0 = 299792458; % speed of light in vacuum in m/s
c0_fr4 = 1/2 * c0; % speed of signal through TL
fr4_inch_per_sec = c0_fr4*100/2.54;
fr4_inchvec = time*fr4_inch_per_sec;
inchvec = fr4_inchvec/2;
figure;
plot(inchvec,abs(impedance));
grid on;
xlabel('Distance (in inches)','FontSize',12,'FontWeight','bold');
ylabel('Impedance (in Ohms)','FontSize',12,'FontWeight','bold');
title('TDR plot','FontSize',12,'FontWeight','bold');