Post Go back to editing

What is the meaning of option 'int_FIR' in internal_design_filter.m (in MATLAB AD936x Filter Wizard)?

Category: Hardware
Product Number: AD9361

The AD936x Filter Wizard package provides a function to design custom filter for the TX and RX path :

The function requires a data structure to design the filter. The data structure should provide the following fields :

% Rdata      = input/output sample data rate (in Hz)
% FIR        = FIR interpolation/decimation factor
% PLL_mult   = PLL multiplication
% Fpass      = passband frequency (in Hz)
% Fstop      = stopband frequency (in Hz)
% Apass      = max ripple allowed in passband (in dB)
% Astop      = min attenuation in stopband (in dB)
% FIRdBmin   = min rejection that FIR is required to have (in dB)
% phEQ       = phase equalization on (not -1)/off (-1)
% int_FIR    = use AD9361 FIR on (1)/off (0)
% wnom       = analog cutoff frequency (in Hz)

Most of the fields of the design structure are quite clear to understand except the exact consequence of :


  1. I can read from the code that the design process is slightly different between (1) or (0). But a more wordy explanation would be welcome (I understand that the FIR filter is normally designed to compensate the analog and HB filters chain ; but in the other case is unclear).
  2. Furthermore, does this option actually disable the FIR filters on the board  as if we used the system command (as described in :

echo 1 > in_voltage_filter_fir_en

  • And finally, it is not clear for me how should I use the output of this internal_design_filter.m function to configure the board from Matlab. Can someone provide a code snippet about that point ?