Unexpected Values in TXP Measurements with RFmx

Updated Nov 5, 2019

Reported In

Hardware

  • PXI Vector Signal Analyzer
  • PXI Vector Signal Transceiver

Driver

  • NI-RFSA

Other

NI RFmx driver

Issue Details

I'm observing unexpected measurements when calculating transmit power (TXP) using RFmx driver and an NI RFSA device.  In particular, I'm seeing different values when using RFSA versus the RFmx driver:





How can avoid this issue?
 

Solution

This behavior can be cased by the LO Leakage Avoidance Enabled Property in RFmx. To replicate the behavior of RFSA in RFmx, you can set the RFmx property LO Leakage Avoidance Enabled to False.

Additional Information

If you are using the RFmx Soft Front Panel, please follow this procedure:
  • From the RFmx SFP click on the configuration button
  • From the Instrument category, go to the LO section.
  • Unselect the Auto LO Leakage Avoidance Enabled proprierty and set the LO Leakage Avoidance Enabled as False.