No that's not what I mean
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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');