05-10-2013 01:56 AM
What is the noise bandwidth of RFSA 5663???
05-10-2013 08:34 PM - edited 05-10-2013 08:37 PM
Hi,
When it comes to 5663 VSA we talk about equivalent noise bandwidth (ENBW). The equivalent noise bandwidth of 5663 VSA will be dependent on the settings you select (e.g. FFT window type). Refer to the following article for more details:
NI 5663/5663E Noise Figure - NI RF Vector Signal Analyzers Help
05-13-2013 02:05 AM
Thanks for your reply.
How about this below specification of RFSA? What is it use for?
Tuned Frequency Equalized Bandwidth
10 MHz to<120 MHz 10 MHz
120 MHz to<330 MHz 20 MHz
330 MHz to 6.6 GHz 50 MHz
I'm measuring a GPS signal at 1176.45 MHz, so its noise BW is at 50MHz, is that correct?
Because, i'm measuring a GPS signal which is very low around -130dBm
Want to know how much gain the RFSA 5663 can provide before applying any external amplification....
Also, can we detect how much gain the 5601 amplifiers/mixer is providing before it goes out as IF signal...
05-13-2013 05:48 PM - edited 05-13-2013 05:51 PM
Hi,
The equalized bandwidth refers to the bandpass bandwidth of the filter on the RF front end of the 5663 device. The equilized bandwidth will vary based on the LO setting. For LO setting within 330 MHz to 6.6 GHz, BW = 50 MHz. Refer to the this diagram for more details. Noise is linked to the RBW (resolution bandwidth specification). "The effective noise bandwidth (ENBW) is generally used for noise level measurement because the shape of the real RBW filter (IF filter provided at the last filtering stage in an analyzer) is not completely rectangular. Effective noise bandwidth (ENBW) is normally represented by k x RBW, where factor k is determined by the shape factor of RBW filter" [1]. To determine how much gain the downconverter applies to the signal you can read the following property, NIRFSA_ATTR_DOWNCONVERTER_GAIN either through LabVIEW or CVI. Refer to the following post for more details: PXIe-5663e block diagram - NI Discussion Forums
05-13-2013 09:02 PM
Thanks a lot for this information, it really have clear explanations.
However, is there an available table where there is corresponding ENBW for each RBW for NI RF VSA products just like the Table 2 of Agilent product note for the different analyzer models....
05-14-2013 01:39 PM
Hi,
Unfortunately, we do not have a similar table for 5663. All the specifications that are public are listed in the NI PXIe-5663E Specifications - National Instruments
Let me know if you have further questions.
Regards,