IFFT for S21 (f) parameter

[yasine79]

Hi aLL,

i made a transmission mesurement (S21) of a dielectric between two Antennas. the length of the frequency sweep is 25 .

my programm is this:


sweep_length=25;
load ATT
load phase
S21=ATT.*exp(1i.*phase);
C=3e8;
stepf=30e6;
dt=1/(stepf*(sweep_length-1));
t=dt*(0:sweep_length-1);

T_domain=ifft(S21,25);
magnitude=20*log10(abs((T_domain)));
figure
plot(t,magnitude)

does the plot make sense? i could not interpret it. maybe you have some advices

thank you