About USRP 2954 phase-aligned operation

[Sasoh]

Hi,

I am using USRP-2954.

Please tell me about the phase synchronization between receiving 2 ports of USRP-2954.

How can I get phase synchronization?

USRP - 2954 is a product of NI, but I think that it is the same as Ettus USRP X310 + UBX 160.

So I understood  "phase-aligned operation across multiple UBX daughterboards on USRP X Series motherboards" from below.

https://kb.ettus.com/UBX 

However, I confirm with the sample software of NI LabVIEW USRP, but phase aligning between the receiving 2 ports does not work well.

Continues waves are output from SG, and distributed with equal length by RF power divider.

I tried two kinds of sample LabVIEW software.

· NI USRP EX Rx Multiple Inputs (Single Device, Multi Channel) .vi

· NI IDL "NI-USRP Simple Streaming"

In both of the above sample programs, the phase difference of the sine wave received by the receiving 2 port is not stabilized every time it is executed.

ex. Set Freq 2.20GHz is well stable. But set 2.21GHz is unstable.

Please tell me how to phase aligning stable with USRP-2954.

Thank you.

--Dolphin System Takuji Sasoh  

[UMASO]

Hello, 

I got exactly the same situation in my project as Takuji has mentioned above.  My customer would like to have a consistent phase relashionship between two LO sources on USRP-2954.  Based on some researches, HW itself has capability to have a fixed phase relasionship between two LO sources, but I do not understand how to access that functionality from LabVIEW software.  Is it possible to have a constant phase relasionship between two LO sources?  If so, is it something that users can do by themselves, or USRP driver should be updated by NI?

Osamu Fujioka
TRIONIX Inc.

CLED/CLA
LabVIEW FPGA and Software Designed Instrument Expert