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AD9361 Lo Freqency Setting

Question asked by liSibet on May 9, 2017
Latest reply on May 10, 2017 by sripad


I just working with AD9361 for a no-os SDR project. Unfortunately, I don't have much experience on this. My questions are: 

(1) I am wondering if RX Lo freqenceny could be any one from 70-6G? The only RX Lo frequency configure content in UG671 is setting Rx VCO Divider register. Thus, is there some limitation to chose Lo frequency point. 

(2) Accoding to theory of direct conversion, f(lo)=f(rf) and there will be no image. However, f(lo) is not strictly same as f(rf) in the project I am working with. It is like f(lo)s are set at 50MHz + 40n (n=0,1,2,3...), each f(lo) will cover +- 20MHz frequency bandwidth. Thus, there is a image of f(rf) along the f(lo)s. For example, If the input signal is 95MHz, the image will appear at 85MHz, which can be easily estimated by the theory.

I want to know if they are be right set in this way ? if it is right, how could I reject those image? like by setting rx path calibration and configuration ?