Sweep Acquisition - Keysight Technologies FieldFox N9912A104 User Manual

SA (Spectrum Analyzer) Mode
SA Mode Settings
— Then choose from the following:

Sweep Acquisition

When set to Auto, Sweep Acquisition is set to the minimum value required with
the current settings in order to achieve amplitude accuracy when measuring
CW signals yielding the fastest sweep update rate.
However, you can adjust this setting in order to increase the probability of
intercepting and viewing pulsed RF signals.
For example, with SwpAcquisition set to Auto a pulsed GSM signal is NOT
visible on the FieldFox screen, as shown in a blue trace in the following image.
While watching the trace, increase the SwpAcquisition value until the pulse
spectrum rises out of the noise and reaches its maximum level. Increasing the
SwpAcquisition value beyond this point only slows the update rate (increases
the actual Sweep time readout) but does not improve measurement quality.
Figure 8-4 GSM Signal in Framed Data Format
In the graphic above, a GSM signal in a framed data format; timeslot zero ON;
all others OFF;
PRF = 218Hz, Duty Cycle = 12.5%. The pulsed signal becomes visible on every
sweep update with SwpAcquisition = 50.
8- 22
— Auto The FieldFox selects the most efficient sweep type based on the
Res BW. When Res BW is set to 200 kHz and below, FFT sweep type
is selected. Above 200 kHz, Step sweep type is being performed.
— FFT The FieldFox uses FFT sweep type regardless of the Res BW.
— Step The FieldFox uses Step sweep type regardless of the Res BW.
This is useful for capturing impulsive noise that may be generated
from nearby electrical equipment.
Keysight N9912-90001 User's Guide