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AD9361 \ ad9364, a noise filtering performance of adjacent channel in TX path?

Question asked by Gennady.Sychev Employee on Nov 26, 2014
Latest reply on Dec 13, 2014 by tlili

Hi, All!

I have one following request.

A designer tests the AD-FMCOMMS3-EBZ and  AD-FMCOMMS4-EBZ TX performance.

The modeling is similar to LTE system, but with lowest bandwidth.

A test stimulus signal with next plot of band power is applied:

Screenshot - 25.11.2014 , 16_23_04.png

An Internal FIR filter is configured for next graph from MATLAB:

Screenshot - 25.11.2014 , 16_13_03.png

The next out was found, for two different frequencies:

 

IMG_20141124_132517.jpg

IMG_20141124_131928.jpg

The influence to adjacent channel is too high then -85db,

Without FIR it looks:

spectr_no_FIR.jpg

What missed ?

What we have to do to achieve suppression equal or better than -65db ?

Do possible it?

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