How to do FFT of decimated digital signals from a ADC?

How to do FFT of decimated digital signals from a ADC?

Hi,

The FFT will not be any different for decimated data, but it will represent a lower bandwidth. The raw data from the ADC (or the ADC core if the decimation filter is integrated with the ADC) will represent a bandwidth of Fs/2 where Fs is the core sample rate. If you decimate by 2, then the decimated data will represent a Fs/4 bandwidth.

Here is a tutorial that you may find helpful:

Mixed Signal and DSP Design Techniques | Analog Devices

Section 5 includes FFTs.

Regards,

David

Hi,

The FFT will not be any different for decimated data, but it will represent a lower bandwidth. The raw data from the ADC (or the ADC core if the decimation filter is integrated with the ADC) will represent a bandwidth of Fs/2 where Fs is the core sample rate. If you decimate by 2, then the decimated data will represent a Fs/4 bandwidth.

Here is a tutorial that you may find helpful:

Mixed Signal and DSP Design Techniques | Analog Devices

Section 5 includes FFTs.

Regards,

David