Ceyear 3943B, Руководство по эксплуатации

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8 Technical indicators and testing methods
8.5 Performance characteristics test
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d) Recording and data processing
Process the test data according to the following formula and record the calculation results in the auxiliary
table B.11. The minimum value of the calculated mirror frequency rejection ratio in each band is recorded
as the summary of the mirror frequency rejection ratio in this band in the functional performance test
record table A.1.
R
image
= P
in
− P
image
.....................................
（
6
）
Where:
R
image
: Mirror frequency rejection ratio.
P
in
: Mirror frequency signal input power.
P
image
: The mirror frequency interference signal level value.
8.5.1.12 Mirror frequency suppression (2 IF)
a) Description of the test items
During frequency mixing, two input signals can generate the same IF signal with that of the LO signal
with the same frequency, with one signal frequency one IF lower than the LO and another signal
frequency one IF higher than the LO. In this case, one of the signal is called the mirror frequency of the
other. Each frequency of the LO has a mirror frequency of corresponding input signal, with the difference
of two IFs between the signal and the mirror frequency. This test is to measure the ability of the
equipment to be tested to suppress the interference signal whose input frequency is the second IF mirror
frequency rate of the equipment.
b) Test diagram and test instruments and equipment
Synthetic Signal Generator ..................................... Recommend 1464/E8257D
Power Meters .............................................. Recommend AV2436/E4419
Power Probes ............................................ Recommend AV71710/9304A
Power Divider .............................................. Recommend 11667C
3.5mm(f)-N type(m) connector
Fig. 8.12 Schematic diagram of the test for mirror frequency suppression (2 IF)
c) Test procedure
1) Connect the test equipment as shown in Figure 8.12.
2) Reset the device to be tested. The device to be tested shares a common time base with the