Ceyear 4051 Series, User Manual

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8. Specifications and test methods
8.5 Performance characteristics test
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Fig. 8.5 Schematic diagram of frequency span accuracy test
2) Set the output power of synthesized signal generator #1 as 0 dBm and the frequency output as on.
3) Set the power of synthesized signal generator #2 as -10 dBm and the frequency output as on.
4) Set the 4051 analyzer according to the relations of frequency span and center frequency listed in B4 of the
4051 Auxiliary Form.
5) Set the synthesized signal generators according to the frequencies of synthesized signal generators #1 and
#2 listed B4 of in the 4051 Auxiliary Form.
6) Execute Single Sweep and wait; execute Peak Search and Marker Delta and then Next Peak Search.
7) Record the Marker Delta frequency value Δf displayed in the 4051 analyzer.
8) Repeat Step 5 to 8 for all frequency span set values and frequencies of the signal generators in relevant
test items in B4 of the 4051 Auxiliary Form.
d) Test records and data processing
9) Calculate the frequency span accuracy δSPAN according to the formula (10) and record it in the 4051
Auxiliary Form.
Where Δf refers to the Marker Delta frequency value Δf displayed in the 4051 analyzer (Hz);
SPAN refers to set frequency span value of the 4051 analyzer (Hz).
8.5.1.1.8 Sweep time and trigger
a) Test items
The amplitude modulation signals are demodulated into periodic amplitude change signals when the
signal/spectrum analyze is in the zero bandwidth state. When the modulation rate of the modulation signals
reasonably correspond to the sweep time of the signal/spectrum analyzer, demodulation signals will be
uniformly distributed on the screen. Calculate the peak value of demodulation signals to obtain the actual
sweep time and then compare it with the designated time to obtain the sweep time accuracy. The sweep time
accuracy is guaranteed in the design. In order to reduce the test time, the typical sweep time will be tested for
verification.
The Trigger function of the analyzer is also guaranteed by the design.