Keysight Technologies C Series - Setting the IF Path; Resolution Bandwidth (Res BW)

268 Keysight N9915-90020 User’s Guide
RTSA (Real-time Spectrum Analyzer) Mode—Option 350
RTSA Mode Settings
Setting the IF Path
How to check or set the IF Path. By default the IF Path is set to Auto.
—Press BW 2.
—Then
IF Path The underlined setting is the current setting. Choose Auto,
10 MHz
, or 100 MHz (100 MHz requires Option B04 or B10 and either
Option 350 RTSA or Option 351 IQ Analyzer).
Optional: After you click 100 MHz, you can use the Freq/Dist hard key and
the number pad or using the numeric keypad, the arrows, to increase
your IF path bandwidth to 120 MHz.
Resolution Bandwidth (Res BW)
In RTSA Mode, the Res BW provides the ability to resolve, or see closely
spaced signals. The narrower (lower) the Res BW, the better the spectrum
analyzer can resolve signals. In addition, as the Res BW is narrowed, less noise
is measured by the spectrum analyzer ADC and the noise floor on the display
lowers as a result. This allows low level signals to be seen and measured.
How to set Res BW
—Press BW 2.
—Then
Res BW.
— Then choose from the following:
When in full span, ADC dither raises the noise floor at the edges of the
120 MHz.
For best results, use the AUTO setting for the Res BW values. Increasing
the resolution BW could reduce pulse measurement capability by
affecting the 100% POI duration and the minimum detectable signal level.
The resolution BW must be as narrow as possible to maintain gapless
measurements.
When Manual RBW is selected, the FieldFox attempts to set the RBW to
the setting you request, but this setting is coupled to the current span
settings. If the manually set RBW is not settable with the current
frequency span value, the FieldFox defaults to the nearest achievable
RBW setting to meet the manual RBW value.