DCA1000EVM: Question on amplitude calibration for 1D FFT result.

Hello,

I am working on ADC raw data processing obtained by DCA1000 + AWR1642.

After applying Hann window and performing 1D FFT on a single chirp containing 2048 ADC samples,

I am able to obtain the FFT result similar in shape with the result from mmWaveStudio.

However, the amplitudes are different.

What I have done to calibrate the amplitude is as below:

1) normalization for Hann_window

scaled by 1/sum of Hann_window

2) normalization for FFT

scaled by 2/number of ADC samples

My FFT result

mmWaveStudio FFT result

Below is the python code which I used to calculate the FFT result.

numADCSamples = 2048
Hann_1D = np.hanning(numADCSamples)
Hann_1D = Hann_1D / np.sum(Hann_1D)
       
f1 = np.multiply(chirp2view,Hann_1D)
f1_fft = abs(fftshift(fft(f1,2048)))/numADCSamples*2
f1_out = np.log10(np.multiply(f1_fft,f1_fft)) * 10 

Do I miss something or make some mistakes?

It will be very appreciated if someone can give me some comment. Thank you!