Tektronix RSA6100A Series, Help Manual

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Analog Modulation > FM Trace Tab
Trace Tab
The Trace Tab allows you to set the display characteristics of displayed trace.
Setting
Description
Show Shows / hides the trace. If the instrument continues to run, the measurement results
below the graph display continue to update even if the trace is hidden.
Detection Sets the Detection method used for the trace. Available detection methods are +Peak,
-Peak, and Avg (VRMS). Not available for saved traces.
Function Selects the trace processing method. The only available setting is Normal.
Freeze Halts updates to the trace.
Save Trace As Saves the trace to a fi le for later recall and analysis.
Show Recalled trace Displays a saved trace instead of a live trace.
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Detection
Detection refers to the method of processing the data acquisition points when creating a trace. The IQ
samples in a data acquisition can be detected in a variety of ways. The number of IQ samples available to
each trace point varies with both analysis length and trace length. For example, with Spectrum Length set
to ‘Auto’ in the Analysis menu, the instrument analyzes just enough samples to produce one IQ sample
pair per trace point. In this case, the detection method chosen has very little effect, as the +Peak, -Peak,
and Avg (VRMS) are all equal. Changing the Spectrum Length causes the available detection methods to
differ in value because they have a larger set of samples for the various detection methods to process.
The available detection methods are:
+Peak – Each point on the trace is the result of detecting the positive peak value present in the set of
IQ samples available to that trace point.
-Peak – Each point on the trace is the result of detecting the negative peak value present in the set of
IQ samples available to that trace point.
Avg (VRMS) [Average V
RMS
] – Each point on the trace is the result of determining the RMS Voltage
value for all of the IQ samples available to the trace point. When displayed in either linear (Volts,
Watts) or Log (dB, dBm), the correct RMS value results. When the averaging function is applied to a
trace, the averaging is performed on the linear (Voltage) values, resulting in the correct average
for RMS values.
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RSA6100A Series Real-Time Spectrum Analyzers Help