Trace Math Functions - Keysight HSA N9342C Demonstration Manual

22 | Keysight | N9342C/N9343C/N9344C HSA Handheld Spectrum Analyzer - Demonstration Guide
Demonstration 12

Trace math functions

The math functions in the N934xC HSA are true power calculations, meaning that the
measurements are converted to power, the math function is performed, and the results are
displayed in dBm.
In this demonstration, we will subtract -6 dBm from 0 dBm and the result will be -1.2 dBm.
In order to get the correct results, the source should be adjusted to as close to the required
power as possible as shown by the analyzer marker:
– 0 dBm = 1 mw
– -6 dBm = 0.25 mw
– -1.2 dBm = 0.75 mw
Instructions for the source
Generate a 1 GHz, 0 dBm CW signal
Adjust the power of the signal to -6 dBm on the HSA
Instructions for HSA
Set the center frequency
Set zero span
Set reference level and scale
Place trace 1 in view mode and trace 2 in clear write mode
Place marker 1 on trace 2
Adjust the power of the signal to -6 dBm on the HSA
Subtract trace 2 from trace 1 and place the result on trace 3
Move the marker to trace 3 and read the results
Keystrokes for the source
[Preset], [Freq], [1], {GHz}, [Amptd], [0], {dBm},
[Mod Off], [RF On]
[Amptd], [-6], {dBm}
Adjust the knob so that the marker on the analyzer reads -6 dBm
Keystrokes for HSA
[Freq], {Center Freq}, [1], {GHz}
[Span], {Zero Span}
[Amptd], [4], {dBm}, {Scale/Div}, [2], {dB}, if needed, adjust amplitude on the
ESG so that the signal on the HSA reads 0 dBm
[Trace], {View}, {Trace (2)}, {Clear Write}
[Marker], {Marker Trace}, {Trace2}
[Amptd], [-6], {dBm}
Adjust the knob so that the marker on the analyzer reads -6 dBm
[Trace], {More 1 of 2}, {Trace Math}, {Math By (Pwr)}, {Math Type}, {A-B->C}
[Marker], {Marker Trace}, {Trace3}
The marker will read approximately -1.2 dBm. To see the difference between
rms power difference and log difference, go to [Trace], {More 1 of 2}, {Trace
Math}, {Math By (Log Pwr}