Calibration of Spectrum Analyzer
Posted: Wednesday 15th Oct 2008, 20:50
I am calibrating an Advantage Instruments ITC 1300C Spectrum Analyzer, I am calibrating the attenuator switch settings by injecting a known (Lab Standard) signal strength into the unit. My question is:
Would it make more sense to inject the proper amplitude signal and calibrate the attenuators at half scale or for top of scale reading?
Logic tells me half scale because I would think that the attenuator accuracy would be more accurate over the entire scale this way (top to bottom).
If I were to calibrate it for top of scale, it would seem that the lower scale readings would be further off.
Unfortunately, the manufacturer is no longer in business and the manual does not specify the proper procedure.
Here is an example of what I am talking about.
I have 4 attenuator switches and they are set up as follows:
+10dbm (full scale)
0dbm (full scale)
-10dbm (full scale)
-20dbm (full scale)
Since the scale is divided into 10 graticules (5 graticules = half), here is the signal levels that I used for calibration:
-30dbm = half scale
-40dbm = half scale
-50dbm = half scale
-60dbm = half scale
I hope I made that easy to follow.
Would it make more sense to inject the proper amplitude signal and calibrate the attenuators at half scale or for top of scale reading?
Logic tells me half scale because I would think that the attenuator accuracy would be more accurate over the entire scale this way (top to bottom).
If I were to calibrate it for top of scale, it would seem that the lower scale readings would be further off.
Unfortunately, the manufacturer is no longer in business and the manual does not specify the proper procedure.
Here is an example of what I am talking about.
I have 4 attenuator switches and they are set up as follows:
+10dbm (full scale)
0dbm (full scale)
-10dbm (full scale)
-20dbm (full scale)
Since the scale is divided into 10 graticules (5 graticules = half), here is the signal levels that I used for calibration:
-30dbm = half scale
-40dbm = half scale
-50dbm = half scale
-60dbm = half scale
I hope I made that easy to follow.