Resolution Bandwidth - Agilent Technologies FieldFox N9912A User Manual





Resolution Bandwidth (Res BW)
In SA 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. However, as the Res BW is
narrowed, the sweep speed becomes slower.
How to set Res BW

 Then
The current Res BW setting is shown at the bottom of the screen.
72
Source Enable ON OFF
Turns ON the internal source.
ON
o
OFF Turns OFF the internal source.
o
Source Mode Trk CW CpCW
The internal source sweeps simultaneously (tracks) with the SA
Trk
o
receiver over the displayed frequency range, emulating NA mode
measurements.
Src
The source is set to a CW frequency independent from the SA setting.
CW
o
is annotated on the screen.
Srcw
The source is set to a CW frequency, but that frequency "tracks" the
CpCW
o
SA receiver Center Frequency setting. Therefore, the signal always appears
at center of the display.

Normalize ON OFF
Normalize ON stores the current measurement trace into Trace 4 in View state
as a reference trace. All subsequent trace measurements subtract out this
Trace 4 reference trace, and therefore become relative to it. This causes
measurements to appear near the ZERO absolute level on the y-axis (0 dBm if
UNIT is set to dBm).
automatically turned OFF when the frequency range or Resolution is changed.
Learn more about Trace Display States on page 78.
Sets the source output attenuation from 0 to 31 dB in 1 dB
Source Atten
steps. Default is 10 dB (approximately -5 dBm output power). While changing
the source attenuation setting, Nominal Output power (an approximation) is
annotated to the right of the active entry setting.
Sets the CW frequency that is used when Source Mode is set
Source CW Freq
to CW.
Press BW 2.
Res BW Auto |
Auto Res BW is coupled to the frequency span. As the frequency span is
o
narrowed, the Res BW is also narrowed providing increased ability to
resolve signals.
To change this setting from Man to Auto, press Res BW twice.
Enter a Res BW value using the numeric keypad, the ▲|▼ arrows, or
Man
o
the rotary knob. Then press a multiplier if necessary or press Enter .
is annotated on the screen.
Srcp is annotated on the screen.
With Source Enable ON and Source Mode = S/R,
is annotated on the screen. Normalize is
SrcN
Man.
N9912A FieldFox User's Guide