[Discuss-gnuradio] Mixing two signals for Radar application.

[Dimitris Siafarikas]

Hi list,

I am in the process of building an FMCW radar. For this to work, I have to mix two signals. I tried to do it with the "multiply" block but no luck. I tried then to see how exactly this block works. It seems that it does not behave As it should be. Referring to theory, I should see the sum and the difference of the two signals. Looking at the FFT plot, I can't say that works.

 

What am I doing wrong? Am I missing something?