Keysight x-series User Reference Manual page 380

8 Frequency Scan Measurement
Measurement Description
A complete Frequency Scan measurement consists of a series of routines, i.e. scanning, search and, a final
measurement.
First, the measurement scans the band based on Scan Table settings specified and activated by the user
to capture the interference spectrum. You can set up to ten ranges in the Scan Table. You can have up to
three traces running with different detectors and trace types. You can enable limit lines that the spectrums
need to meet, and optionally include a limit margin.
Next, the measurement will search for the peak signal. The search is based on the peak excursion and peak
threshold setting that you define. You may optionally include a limit margin for the search. This process is
also known as the data reduction stage. There will be a cross mark added onto the trace for each peak
signal found.
For each of the peak signals found, the instrument will be tuned to the signal frequency in zero span and
dwells for the dwell time specified. Since EMI standards usually specify limits for different detectors, you
may specify up to a maximum of three final detectors. Each detector can have its own dwell time settings.
Each signal in the list will be updated with the final detector and delta limit values when the final
measurement is completed.
In some cases, you may not want to run the complete Frequency Scan measurement, so you have the
flexibility to control the measurement routines. You can choose just to run scan, search, or the final
measurement on a measured trace, or re-measure for only certain specific signals in the list.
Alternatively, you can perform the measurement using the measure at marker function. If a marker has
been turned on, the measurement is performed at the marker position. If no marker is present on the
screen, then one is turned on and placed on the highest peak on the screen. Similar to the final
measurement, the measure at marker function consists of making a zero span measurement on each peak
using the specified final measurement detectors and dwell times
You can export both scan table and signal list results for analysis. The exported scan table and signal list
can be easily imported into the measurement. The data in the signal list table are persistent, which
survives a mode preset and power cycle. Manipulation of a signal list such as the sorting a signal display,
deleting a signal, marking a signal in the list, and copying a signal list are available.
380 EMI Receiver Mode Reference