National Instruments PXIe-5185, Руководство пользователя

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PXIe-5185/5186 Calibration Procedure | © National Instruments | 11
18. Repeat steps 15 through 17 for each configuration in Table 2, recording each result as
splitter output 1 power , where each configuration has a corresponding value.
19. Calculate the splitter imbalance for each frequency point using the following equation:
splitter imbalance = splitter output 2 power - splitter output 1 power
20. Disconnect the 50 Ω SMA terminator (f) from splitter output 2. Refer to the remaining
assembly as the power sensor assembly . The power sensor assembly will be used in the
Verifying 50 Ω AC Amplitude Accuracy and Bandwidth procedure.
BNC Adapters
This procedure characterizes the power splitter imbalance when using BNC adapters. The results
of this characterization are later used as a correction in the
Verifying 1 M Ω AC Amplitude
Accuracy and Bandwidth procedure.
1. Connect the BNC (f)-to-N (f) adapter to the power sensor. Refer to this assembly as the
power sensor .
2. Zero the power sensor as described in the Zeroing the Power Sensor section.
3. Connect the RF OUT connector of the signal generator to the input port of the power splitter
using an SMA (f)-to-N (m) adapter and an SMA (m)-to-SMA (m) cable.
4. Connect an SMA (m)-to-BNC (m) adapter to one of the power splitter output ports. Refer
to this assembly as
splitter output 1 .
5. Connect the 50 Ω BNC terminator (f) to splitter output 1.
6. Connect the other SMA (m)-to-BNC (m) adapter to the other output port of the power
splitter. Refer to this assembly as
splitter output 2 .
Table 3.
Power Splitter Characterization with BNC Configuration
Configuration
Test Point
Impedance Frequency (MHz) Amplitude (dBm)
1 1 M Ω 0.05 -0.5
2 1 M Ω 425 -0.5