Hello guys, good morning to everyone. So to say, I am a beginner in antenna design and digital signal processing using CST and MATLAB. I am unable to do IFT of S11 parameter. How can I convert S11 parameter(CST) using CST from the time domain into frequency domain for further processing using CST or MATLAB?
scattering parameters are always frequency domain parameters. In so far "convert S11 parameter... from the time domain into frequency domain" makes no sense. Calculating a simulated TDR response from S11 measurement by means of IFT (= converting from frequency domain to time domain) is possible and provided by advanced VNA instruments.
EM solvers like CST working in time domain do that FFT internally. Internal calculation is time domain, but resulting S-parameters are already the converted frequency domain results.