Agilent Technologies X Series Manual page 249

when PXA or Option B40 is installed, continuous bandwidth setting is possible. For any other
configuration, only fixed bandwidth values are available and quantizing the bandwidth values becomes
necessary.
Continuous bandwidth setting is available in this configuration. Hence the theoretical coupling equation
above with span is used in all cases except when the bandwidth reaches the maximum value, which in
this case, is clipped to the maximum value.
Note that if the Digital IF BW state is set to Man and not Auto, any value greater than the Span is
settable.
There are coupling dependencies with the IF Path Selection parameter. The IF Path Selection determines
the maximum value and maximum resolution values. For instance, even with the B40 and B1X options
installed on a PXA, if the IF Path Selection is set to 25 MHz with the IF Path Auto set OFF, the
maximum bandwidth value will be clipped to 25 MHz.
The Digital IF BW parameter directly sets the digital IF filter bandwidth, which can only be set to certain
fixed discrete values. Thus, the theoretical value of the Digital IF bandwidth will be derived first. Then
the closest discrete bandwidth value will be selected from the filter table. The exception is 25 MHz
where, if the theoretical value exceeds 10 MHz, the 25 MHz bandwidth will automatically be selected.
For example, if you set the Span to 2.9 MHz and 3.0 MHz, the theoretical Digital IF BW value will be as
follows.
Digital IF Bw = (2.9 MHz) x 1.5 = 4.35 MHz
Digital IF Bw = (3.0 MHz) x 1.5 = 4.5 MHz
If you have the Flattop filter selected, only 4 MHz and 5 MHz bandwidths are available. For in-between
values, the next widest possible value is selected. In this case, both 4.35 MHz and 4.5 MHz are rounded
to 5 MHz.
Key Path
Mode
Remote Command
Example
Notes
Meas Setup, Advanced
BASIC
[:SENSe]:SPECtrum:DIF:BANDwidth <freq>
[:SENSe]:SPECtrum:DIF:BANDwidth?
[:SENSe]:SPECtrum:DIF:BANDwidth:AUTO ON|OFF|1|0
[:SENSe]:SPECtrum:DIF:BANDwidth:AUTO?
SPEC:DIF:BAND 1MHz
SPEC:DIF:BAND?
SPEC:DIF:BAND:AUTO 0
SPEC:DIF:BAND:AUTO?
You must be in the IQ Analyzer (Basic) mode to use this command. Use
INSTrument:SELect to set the mode.
Complex Spectrum Measurement
Meas Setup
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