Agilent Technologies Signal Analyzer N9030a - Manual (Page 1356)

6 RLC Swept SA Measurement Front-Panel & SCPI Reference
Trace/Detector
traces for which this detector is selected (other than to slow down the sweep, because of the
coupling to Sweep Time of VBW). If any traces are active for which VBW does not apply (traces
with Average, EMI Average, RMS Average or Quasi Peak detectors), then an * displays after the
VBW annotation on the front panel.
Selecting a specific detector type turns the “ "Auto " on page 1351 ” (to false for this trace
(manual).
Selecting a detector for a trace (pressing the key or sending a [:SENS]:DET:TRAC command) puts
Update On and DisplayOn for that trace, even if that detector was already selected. Note that
the legacy command [:SENS]:DET[:FUNC] does NOT exhibit this behavior.
Selecting a detector, whether by pressing the softkey or sending the equivalent SCPI command,
will turn trace math to Off for the selected/specified trace.
Initial S/W Revision A.02.00
More Information
In the past, Quasi Peak and EMI Average measurements were often made on a linear display scale
because those detectors only worked properly with signals on a linear (voltage) scale. The X-series
analyzers are capable of making Quasi Peak and EMI Average detected measurements correctly on
a log scale, due to the digital IF. This latter capability means that the user can observe detected
EMI levels on a log scale, allowing a large visible dynamic range.
Also in the past, EMI analysis equipment would need to perform a ranging operation to set the
reference level when one of these detectors was turned on, but the X-series analyzers do not -
because of its digital IF, there is no need to set the reference level (range) to improve the accuracy
nor to allow visibility of the detected level.
EMI Average
Only appears with the N6141A or W6141A application or Option EMC installed and licensed.
The EMI Average detector in Agilent’s X-Series analyzers is so called to distinguish it from the
Average detector, although EMI users typically refer to it simply as the “Average detector”. The
intent of this detector is to provide a standard means to “smooth” the signal while still providing
compliance to CISPR pulse response standards.
Unlike the regular Average detector, which averages on a bucket-by-bucket basis using either a
power, log-power or voltage scale (a bucket is the same as a trace point), the EMI Average detector
displays the average value, on the voltage scale, of the overall amplitude envelope, independent of
the trace bucket width. It is defined for EMI measurements by the CISPR 16–1–1 standard and,
in the X-series, uses a sophisticated algorithm to implement a lowpass filter that conforms to the
latest CISPR standard.
1356 Remote Language Compatibility Measurement Application Reference