NI 5644R calibration Problem

[walidbalid]

Hello-I did a self-calibration for two of our PXIe-5644R. I'm using VSA driver (Acquisition Type: Spectrum) to scan 80MHz span in 5GHz band (802.11ac/80MHz signal). After the calibration, the spectrum graph started showing splits (sections) in the signal as shown in attached figures number 1, 2, and 3!

I checked the instantaneous BW and found to be 84MHz instead of 80MHZ (Span). When I set the down-converter center frequency value to the band center frequency value, the problem was solved (figure 4). However, the LO frequency tone started appear on the spectrum graph at the band center frequency (figure 5)!

I think the LO is set each 26~27 MHz causing this sectioning issue!

Does anyone can help me out to solve this problem?

Thanks in advance!                     

[DollaBrillz]

Hi Walid,

Thank you for posting these pictures and opening up this conversation to our online community. However, as we currently have a Service Request open for this issue, I will be working with my colleagues here and will respond to you over email.