RFSA/RFSG modules

[Titanium]

Currently have 2 VSG (5673E) & 2 VSA (5663E) 

1.) how fast does the RFSA/RFSG modules switch their frequency of operation

2.) IIs there a mode that can be used to achieve the fastest frequency switching rate? List Mode???

3.) How low is the typical noise floor for the RFSA modules in the 400MHz - 900MHz frequency range?

     For a BW of 6MHz in this frequency range, would it be possible to get a noise floor lower than -114dBm as required by the standard?

Thanks...

[JoshY]

Hi Titanium,

According to the PXIe-5673E specifications, the frequency settling time to get to ≤0.1 × 10-6 of your final frequency has a median of 1.5 ms for low loop bandwidth and 2 ms for high loop bandwidth. This can be found on page 6 and 7 of the linked document. Please note that large frequency shifts and operating system speeds can also affect this. Also, list mode would likely be the way to go, but this depends largely on your application.

Next, according to the PXIe-5663E specifications, the tuning time can be expected to be around 6 ms for narrow loop bandwidth and 3.7 ms for wide loop bandwidth to be within 0.1 × 10–6 of your final frequency. This can be found on page 18 of the linked document. The noise specs are listed on page 8- from 120 MHz to 3 GHz, -158 dBm/Hz is typical.

I hope this helps!

Regards

[mbb25]

Small typo in JoshY's post.  Should say 0.2 ms median tuning speed for 5673 with high loop bandwidth, as indicated in the 5673 spec sheet.

[KittF]

To which standard are you referring?      "-114dBm as required by the standard"

I'd be surprised to see  -114dBm at a resolution bandwidth of 6MHz (don't think this is theoretically possible, right?)

As you increase your RBW above 1Hz, the floor will rise based on 10*log (RBW). Thus if you are using a 6 MHz RBW, you must add ~68dB to the noise 1Hz noise floor

10*log(6MHz) = 67.8dB

For the 5663, this yields ~90dBm noise floor when normalized to 6MHz RBW.  http://www.ni.com/white-paper/7291/en/

Theoretical lowest noise floor is -174 dBm/Hz or -106 dBm/6MHz, which would be super awesome  😃

[Titanium]

This is referring to Digital TV signals: -114 dBm, averaged over a 6 MHz bandwidth