hello,when I use AD6688 to catch noise or signal.I found there is dc frequence when I pwelch the spectrum .It makes the stray when mixed the dc and local oscillator from AD6688.
I found the phenomenon always existed. However,when I configure the AD6688 resigster through the SPI. I didn't find the resigster about how to remove the dc.
Please help me whether there are resigsters about it .Thank you!
can you please send screenshots? I am not sure what you are talking about here. Also, what is the AD6688 setup here?
Hello,this is my spectrum when I use AD6688 to catch a single-tone in 635MHz. The sample rate I used is 2.5GHz . The frequency of DDC is 625MHz and the decimation ratio is 16.There are three extra spectral lines in the center of my spectrum. I don't know how it is formed. The configuration of AD6688 is shown in the pictures, can you help me?
Decimation ratio is not 16 per your screenshot. You have set it to decimate by 2. Please follow the instructions in the wiki use guide to understand how to setup the AD6688 correctly
Sorry,it's my written mistake,I set it to decimate by 2.
I think the spectral line in the center of the spectrum is that the DC component was moved to the 625MHz IF, but I don't understand why it has such a large power. As for the two lines next to it, I don't understand what it is.Can you help me?