Hi Stepan,
You can calculate the S11 parameter from tdr data by performing Fourier Transform analysis. Here is an example to demonstrate how you can achieve this:
Step 1: Calculate Hann window using "hann" function.
windowed_tdr = tdr .* hann(length(tdr));
Step 2: Calculate fourier transform uisng "fft" function.
% Calculate fft
fft_result = fft(windowed_tdr);
% Process the FFT result
% Normalize the frequency axis
Fs = 1 / (t(2) - t(1)); % Sampling frequency, assuming uniform time step
n = length(fft_result); % Number of points in FFT
f = (0:n-1)*(Fs/n); % Frequency vector
% Scale the FFT result to account for the length of the signal and the window function
fft_scaled = fft_result / (sum(hann(length(tdr))) / length(tdr));
Step 3: Extract s11 parameters
% Extract S11
s11 = fft_scaled(1:n/2); % Take only the first half of the FFT result
s11_magnitude = abs(s11); % Magnitude of S11
s11_phase = angle(s11); % Phase of S11
Please refer to the following MathWorks documentation for more information on:
- hann - https://www.mathworks.com/help/signal/ref/hann.html
- ftt - https://www.mathworks.com/help/matlab/ref/fft.html
Hope this helps!
