Ceyear 4051 Series, User Manual

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8. Specifications and test methods
8.5 Performance characteristics test
655
b) Test equipment
Synthesized signal generator (E8257D/1464 is recommended)
c) Test steps
1) Connect the test equipment as shown in Figure 8.3.
2) Set the synthesized signal generator frequency as 1 GHz and the amplitude as 0 dBm.
3) Reset 4051 and set as follows:
Center frequency as 1 GHz
Span: 1MHz
Fig. 8.3 Schematic diagram of residual frequency modulation
4) Gradually reduce the frequency span to 100 Hz and press Peak Search to move the signal to the center
frequency.
5) Set 4051 amplitude scale as 2 dB/division and adjust the output amplitude of the signal generator to place
the signal peak at the reference level.
6) Execute Peak Search to adjust the peak to the center and execute Marker Delta.
7) Turn the analyzer knob anticlockwise until the Marker Delta amplitude reading is closest to -5 dB.
Execute Marker Delta.
8) Turn the knob anticlockwise until the Marker Delta amplitude reading is closest to -10 dB.
9) Record current frequency difference Δf and the amplitude different ΔL of the Marker Delta, calculate the
demodulation sensitivity S according to the formula (7) and record the result in the 4051 Auxiliary Form.
10) Execute Peak Delta and Marker Delta. Turn the knob anticlockwise until the Marker Delta amplitude
reading is closest to -10 dB. When the marker points step by 1 Hz at such time, select the marker point
closest to -10 dB, execute marker-to-center and set the frequency span as 0.
11) Set the analyzer sweep time as 1 s, execute Single Sweep, press Peak Search, execute Marker Delta and
turn the knob to move the marker to the lowest. Record the absolute value of the Marker Delta amplitude
(amplitude offset) ΔA in B2 of the 4051 Auxiliary Form.
12) Change the output frequency of the signal generator and the center frequency of the 4051 analyzer and
repeat step 2 ~ 11.
d) Test records and data processing
13) Calculate the residual frequency modulation RFM according to the formula (8) and record it in the 4051
Auxiliary Form.