I transmit a phase modulated (Barker modulation) signal that has a 5 MHz -3 dB frequency.
I try to filter this signal using the AD9361 FIR in order to clean the spectrum out of the Tx permitted frequency.
For some reason the AD9361 FIR does not have any effect on the Tx signal as can be observed below. I have tired several FIR variations with different bandwidth values.
What can be the reason for this issue?