ktr
Full Member level 3
Hello All,
I need to understand noise floor concept in Spectrum Analyzer. My spectrum analyzer has a
Noise Figure = DANL of system [dBm/Hz] - Thermal Noise (-174 [dBm/Hz]) with a DANL of -152dbm/Hz
so a nf=22db
As I change the vertical scale and reference level of the spectrum analyzer, its noise floor is dropping also; and its written as dbm. When I put vertical level at 150db and reference level to -50dbm; its noise floor is down to -160dbm. However, it confuses me if that's just a graphic bug; or real noise floor.
1- Termination with 50-ohm ends up with the referenced levels of floor when observed with Span=1khz and RBW=1hz
2-When I connect DUT onto it, with low reference level everything on screen gets weird; but when I choose high reference level; then floor gets higher.
I read about the function of reference level in some places; but it's not clear in my mind.
Any comments are welcome.
Kind Regards,
ktr
I need to understand noise floor concept in Spectrum Analyzer. My spectrum analyzer has a
Noise Figure = DANL of system [dBm/Hz] - Thermal Noise (-174 [dBm/Hz]) with a DANL of -152dbm/Hz
so a nf=22db
As I change the vertical scale and reference level of the spectrum analyzer, its noise floor is dropping also; and its written as dbm. When I put vertical level at 150db and reference level to -50dbm; its noise floor is down to -160dbm. However, it confuses me if that's just a graphic bug; or real noise floor.
1- Termination with 50-ohm ends up with the referenced levels of floor when observed with Span=1khz and RBW=1hz
2-When I connect DUT onto it, with low reference level everything on screen gets weird; but when I choose high reference level; then floor gets higher.
I read about the function of reference level in some places; but it's not clear in my mind.
Any comments are welcome.
Kind Regards,
ktr