NI 5665 RF Vector Signal Analyzer Equivalent Noise Bandwidth Constants

[tylim]

Hi,

May I know that the equivalent noise bandwidth constants of NI 5665 RF Vector Signal Analyzer when certain spans and resolution bandwidth (RBW) are used? Is there a formula relating among them or any table which I could refer? I am looking for the equivalent noise bandwidth constants because I would like to use these constants in direct phase noise measurement test.

Thank You.

Regards,

tylim

[Titanium]

Maybe check this link, same inquiry about VSA.

Same case as NI-5663, no corresponsdence table for the RBW and ENBW (effective noise bandwidth).

"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"

[tylim]

Ok. Thanks Titanium.

Actually my purpose of getting the effective noise bandwidth (ENBW) is to obtain the phase noise correction when certain RBW and span are set. May I know that the formula to obtain the phase noise correction is this, phase noise correction = 10 log (ENBW / 1hz), or in other word, phase noise correction = 10 log ((k x RBW) / 1hz), in NI 5665 where k is the downconverter gain?

Thank You.

Regards,

tylim