Agilent Technologies Signal Analyzer N9030a - Manual (Page 1382)

6 RLC Swept SA Measurement Front-Panel & SCPI Reference
Trace/Detector
(as before). When Normalize is turned on, the result is the calibrated return loss in dB. For a
more accurate calibration, an Open and Short can be used. To do the Open/Short calibration, the
Open/Short key at the bottom of the Normalize menu is pressed. This will initiate a guided
calibration procedure which captures the reference trace. This is then stored to Trace 3, as
before. When Normalize is turned on the corrected return loss is displayed.
Measurement Details
First the following calculation is performed:
Trace 1 = (Trace 1D – Normalized Trace)
Where:
Trace 1D is the measured value of trace 1, as it comes from the SENSe subsystem.
Normalized Trace is Trace 3, in which you have previously stored a reference trace
All values are in decibel units.
This Trace 1 contains the values that will be returned from a trace query, or if the marker is
placed on the trace.
For example, let's say bucket 1 on Trace 1 is at 0 dBm, and bucket 1 on Trace 3 is at 10 dBm. The
resultant bucket is at 0 dBm – 10 dBm = –10 dB (just like with a delta marker).
You are also given the ability to define what (dB) value to use for Ref Level, and to define where
on the screen the Ref Lvl line will appear using Normalized Reference Position. This flexibility in
displaying the result allows a wide range of devices, including amplifiers, to be tested using
Normalize.
In the example above, bucket 1 has the value of –10 dB. Let us assume you have set Norm Ref Lvl
to 5 dB. Thus bucket 1 will display 1.5 divisions below the Reference Level line (assuming 10 dB
per division).
The Reference Level line is normally the top line of the graticule. If Norm Ref Posn is set to 10,
this is the case. If it is set to 9, it is the next line down. If it is set to 5, it is the middle line of the
graticule. If set to 0 it is the bottom line.
So in the example above, if Norm Ref Posn is set to 9, then bucket 1 will display 2.5 divisions
below the top line of the graticule.
None of the manipulations of Norm Ref Posn and Norm Ref Lvl affect the data in the trace.
As Normalize displays a ratio between two traces (a difference, in dB) the Y-Axis Unit while in
Normalize is dB in Log Amplitude and dimensionless in Linear. The Y Axis Unit chosen in the Y
Axis Unit menu is unaffected by Normalize. When you leave Normalize the Y Axis Unit returns to
the value set in the Y Axis Unit menu. While in Normalize, all amplitude functions, such as
Marker Y and the values in other traces, should be always in db unit, and so should the returned
1382 Remote Language Compatibility Measurement Application Reference