USRP2900 - PLL - Switch "REF-IN" vs. "Internal Oscillator"

[Xiaoxizhou]

Hi Thierry.LE_GALL

          My professor gave me a Software Defined Radio for experiment. During the process,I found one of your program on NI official website. But it seems a litter hard for us to understand the graph. So,I hope get  your guidance of  below  questions. What does x-axis come about(which symbol frequency) and that does the Y-axis(which symbol magnitude) mean?

          Looking forward to your reply。

[Thierry.LE_GALL]

Hi,

X-axis is the normalized frequency (1/fe) where fe is the IQ rate (200 kHz). Y-axis is the logarithm of the modulus of the FFT of the I or the Q baseband signal in the receiver.

Regards,

Thierry