agent38
Electrical
- Jun 19, 2012
- 7
I am trying to run a RF test to look for spurs and harmonics for a Transmitter DUT. Basically I'm injecting power from a signal generator into the DUT and on the SPEC AN with the proper span I want to look at spurs and harmonics.
Without doing anything with the equipment yet I'm trying to just visualize in my mind what my reference level should be set to on my Spec AN because the output of the DUT is +24dBM (SPEC AN max input limit is +31dBm) and my spurs and harmonics are expected to be much smaller in power than the fundamental (i.e. -60dBm) (know this because DUT modeled in keysight genesys).
What I'm really saying is that although my SIG GEN is creating a 3GHz carrier at -6dBM power level, its coming out of the DUT going into the Spec AN at 3GHz +24dBm and 3GHz is not on the SPEC AN frequency span window because I'm looking 2x, 3x away from the fundamental carrier. (i.e f1 = 3GHz, 2xf1 = 6GHz, 3xf1= 9GHz)
So when looking at smaller signals 2x, 3x away from my carrier should my SPEC AN reference level be set slightly higher than the fundamental frequency power level (+24dBm) that's not seen on the spec an? Or should my reference level be set slightly higher than the spurs or harmonics power levels im expecting to see at -60dBm that will be on the SPEC AN window span?
Reading some generic SPEC AN tutorials on line (I.E. Rhodes and Schwarz)
" Reference level is the top edge of display and represents the maximum expected power at the spectrum analyzer input. In most cases, the reference level is adjusted so the highest level of the signal is slightly below this level."
So do they mean literally the reference level should be set to highest level to the input of the SPEC AN even if its not on the SPEC AN span window or do they mean the highest input signal positioned on the SPEC AN window span?
Because their words say one thing but the image they show says something different.
Without doing anything with the equipment yet I'm trying to just visualize in my mind what my reference level should be set to on my Spec AN because the output of the DUT is +24dBM (SPEC AN max input limit is +31dBm) and my spurs and harmonics are expected to be much smaller in power than the fundamental (i.e. -60dBm) (know this because DUT modeled in keysight genesys).
What I'm really saying is that although my SIG GEN is creating a 3GHz carrier at -6dBM power level, its coming out of the DUT going into the Spec AN at 3GHz +24dBm and 3GHz is not on the SPEC AN frequency span window because I'm looking 2x, 3x away from the fundamental carrier. (i.e f1 = 3GHz, 2xf1 = 6GHz, 3xf1= 9GHz)
So when looking at smaller signals 2x, 3x away from my carrier should my SPEC AN reference level be set slightly higher than the fundamental frequency power level (+24dBm) that's not seen on the spec an? Or should my reference level be set slightly higher than the spurs or harmonics power levels im expecting to see at -60dBm that will be on the SPEC AN window span?
Reading some generic SPEC AN tutorials on line (I.E. Rhodes and Schwarz)
" Reference level is the top edge of display and represents the maximum expected power at the spectrum analyzer input. In most cases, the reference level is adjusted so the highest level of the signal is slightly below this level."
So do they mean literally the reference level should be set to highest level to the input of the SPEC AN even if its not on the SPEC AN span window or do they mean the highest input signal positioned on the SPEC AN window span?
Because their words say one thing but the image they show says something different.