Agilent Technologies Signal Analyzer N9030a - Manual (Page 555)

6 RLC Swept SA Measurement Front-Panel & SCPI Reference
BW
1. If the detector is Peak and the EMC Standard is set to either CISPR or MIL, use 10.0 (we use
wide VBWs to capture peak levels accurately).
2. Otherwise, if the detector is Negative Peak, use 1.0 (in the Negative Peak case, there are no
known significant use models so we use a medium ratio).
3. Otherwise, if the detector is Normal, use 1.0.
4. Otherwise, if the detector is Average, and the span in nonzero, use 0.1. The use of a small ratio
in Average detection is desirable because of its effect on the sweep time equations. The VBW
filter is not actually in-circuit when the average detector is on. If the detector is Average, and
the span is zero, use 10.0, which gives optimal behavior for Interval Markers in zero span.
5. Otherwise, if the detector is EMI Average, Quasi Peak or RMS Average, use 10.0. In fact this is
a “don’t care” since no VBW is used for these detectors, as noted under “Dependencies” for the
VBW key
6. Otherwise, the detector is simply Peak or Sample. These two detectors can use the same rules. In
these cases, if any active trace is in max hold or min hold, use 10.0, because Max and Min Hold
operations will usually be intended to capture peaks and pits without smoothing from the VBW
filter; otherwise, use 1.0 as a compromise, because you have not set the analyzer in a way that
implies that you are measuring noise, pulsed-RF or CW signals, and for backward compatibility
with earlier analyzers.
Note that because the above couplings depend on which traces are active, they are re-examined
whenever any trace goes active or inactive, except when this leaves no traces active. Transitioning
to the state where no traces are active should not affect the couplings; in that way, the annotation
will always reflect the state of the last trace which was active.
Span:3dB RBW
Selects the ratio between span and resolution bandwidth.
Normally, Span:3dB RBW (Auto) selects a Span:3 dB RBW ratio of 106:1. If you manually enter
the ratio, Man will become underlined, which enables you to manually select ratios more suitable
for certain measurements.
When the Span:3dB RBW is manually selected, it may be returned to the coupled state by pressing
the Span:3dB RBW key until Auto is underlined. This may also be done by pressing Auto Couple
or by performing a Preset.
Key Path BW
Remote Command [:SENSe]:FREQuency:SPAN:BANDwidth[:RESolution]:RATio <integer>
[:SENSe]:FREQuency:SPAN:BANDwidth[:RESolution]:RATio?
[:SENSe]:FREQuency:SPAN:BANDwidth[:RESolution]:RATio:AUTO OFF | ON | 0
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Remote Language Compatibility Measurement Application Reference 555