Ceyear 4051 Series, User Manual

Page: 686 / 751

8. Specifications and test methods
8.5 Performance characteristics test
672
The signal peak amplitude offset displayed in the signal/spectrum analyzer will be the resolution bandwidth
switching error only by inputting a stable signal and changing the resolution bandwidth of the 4051 analyzer.
b) Test procedure
1) Reset the 4051 analyzer and complete all calibrations.
2) Set the 4051 input as the calibration interface and the calibration source as 500 MHz and set the following
parameters:
Center frequency: 500MHz
Span: 500kHz
Reference level-18 dBm
Logarithmic scale dB/division1 dB
Resolution bandwidth: 300kHz
VBW/RB: 0.1
3) Execute Peak Search and Marker Delta.
4) Set the 4051 analyzer according to the resolution bandwidth listed in the 4051 Auxiliary Form and set the
ratio of the frequency span against the resolution bandwidth as approximately 2 times.
5) Execute Peak Search and record the marker difference reading as current resolution bandwidth switching
error.
6) Repeat Step 4 to 5 for remaining resolution bandwidths in B12 of the 4051 Auxiliary Form.
c) Test records and data processing
7) Determine values in all test items in B12 of the 4051 Auxiliary Form and find the positive maximum error
value Δ A
max
and the negative minimum error value Δ A
min
of each band. Such two values should fall
within the resolution bandwidth switching error range of the 4051 analyzer, otherwise it will be
considered as noncompliant.
8) Calculate the resolution bandwidth switching error ΔA according to the formula (20) and record it in the
4051 Record Sheet.
8.5.1.2.8 Reference level
a) Test items
The calibrated vertical scale position on the screen of the signal/spectrum analyzer is used as the reference for
amplitude measurement and the reference level usually refers to the top scale line. Switching of the reference
level will cause the linkage of gain/attenuation. The reference level switching error is used to assess the error
of the switch gain of the 4051 analyzer. By changing the set value of the standard attenuator, the error
between the marker reading difference and the calibration value of the standard attenuator caused by
switching of the reference level will be the reference level switching error.
b) Test equipment
Synthesized signal generator (E8257D/1464 is recommended)
84906L is recommended for the standard attenuator.
11713C is recommended for the attenuator drive.
c) Test steps