I have been reviewing the AD9361 documentation (Data sheet, UG-570 and UG-671) and I'm don't currently see how the how the internal 56 MHz analog bandwidth can be fully utilized / occupied for the Rx path.
There are several posts that discuss that the maximum data rate of the ADC out of the AD9361 is 61.44 MHz so given that is the max. rate, wouldn't that mean the maximum Nyquist bandwidth of the input signal can only be 30.72 MHz? If that's the case, then why is the internal bandwidth of the analog filters set at 56 MHz instead of something lower that is closer to 30.72 MHz?
Is this additional bandwidth necessary in order for Rx Decimation Digital Filtering and Equalization stages prior to the ADC to work properly given that the Delta-Sigma ADC is running at up to 640 MHz? Or are there other reasons why the analog path for the AD9361 is currently set to the 56 MHZ maximum?
Any feedback would be appreciated.