Ceyear 4051 Series, User Manual

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4. Operating Instruction
4.1 Function operation guide
83

Voltage Average Detector
Also called average (AVG) detector. Take linear average for all sampling data assigned to each trace point;
the 4051 Series Signal Analyzer envelopes the detector for the RF input signal and obtains linear voltage.
After summing those voltage values, divide the number of sampling data points corresponding to each trace
point. When the scale is logarithm, take 20 times of logarithm transformation for these RMS values (with 10
as base) and obtain the trace data. When the scale type is linear, those average values are trace data.
 Video Average Detector
Also called Logarithm Power Average Detector, i.e., take the logarithm power average value for all data
assigned to each trace point; earlier Series Signal Analyzer generally displays the measurement trace of
logarithm scale, and all filtering and averaging are based on the logarithm power data; the trace is generally
called as video signal. After digital IF processing is adopted, to make measurement results same as the earlier
Series Signal Analyzer, the video average detector function is added.
The trace detector mode of 4051 Series Signal/Spectrum Analyzer can be manually set or set as auto selection.
When the detector mode is set as auto selection, the Series Signal Analyzer will automatically select the
suitable detector mode based on the current trace processing mode, marker function and trace average type.
2) Concept of trace processing
When the Series Signal Analyzer is in the continuous sweep mode or has carried out the sweep measurement
continuously for many times, the trace processing mode determines how the current measured trace deals with
the previous measured traces to obtain new trace.
The 4051 Series Signal/Spectrum Analyzer has four trace processing modes:
 Refresh
New trace is directly assigned with the current measured trace, irrelevant with the previous measured traces.
 Average
Based on the average count N set in the
【
Meas Setup
】
, update trace is obtained after averaging the
performance index of the measurement trace.
Detailed algorithm:
New trace = ((K-1) previous trace + current measurement trace)/K
Where, K is accumulated average count.
Under continuous measurement, when K is accumulated to the average count N set in the
【
Meas Setup
】
,
the K will always equal to N. Under single measurement status, when K is accumulated to the average count
N set in the
【 Meas Setup 】 , the measurement will stop.
 Max. Hold
The new trace data is assigned with maximum value of previous measured trace data.
 Min. Hold
The new trace data is assigned with minimum value of previous measured trace data.
For each trace activated, the trace processing mode is defaulted to refresh in the 4051 Series Signal/Spectrum
Analyzer.
3) Trace display ON/OFF
The trace display ON/OFF indicates whether the trace will execute and be displayed on the display are of the
front panel. There are four types of the 4051 Series Signal/Spectrum Analyzers:
 Refresh Display
(Trace on)
New trace will execute refresh in the internal part of application (backstage) and will be displayed on the
display area of the front panel.