[USRP-users] X310, 2 channel sample time and phase alignment

Kemp, Elizabeth - 1008 - MITLL Elizabeth.Kemp at ll.mit.edu
Tue Sep 2 11:23:22 EDT 2014


Hi,



I have a test set up where I am recording on both channels of an X310.  I have the output of a signal generator connected to the channels through a splitter (and equal length cables).  I am using the BasicRX Daughterboards (1-250 MHz).



I have attached a screenshot from GRC of the WX GUI that shows a plot of the real samples, and the magnitude of the two channels.  As you can see in the magnitude plot, the two channels seem to be time-aligned, but there is a huge phase offset between the two channels.  I've observed that the phase offset varies across different frequencies.



So my question is - why is there a phase offset between the 2 channels?  Is there anything that can be done to correct it?



Thanks for your help,

Liz
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