Tektronix P6248, Руководство по обслуживанию

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Performance Verification
14
P6248 1.7 GHz Differential Probe Service Manual
Common-Mode Rejection Ratio
The following steps prepare the network analyzer for measuring common-mode
rejection ratio. The actual settings may vary with different models of network
analyzer. Refer to the user documentation supplied with the network analyzer for
details on performing these steps.
NOTE
. The alternative procedure for testing CMRR without a network analyzer
begins on page 39.
The 1103 power supply can operate two probes. To keep the probe warmed up,
move it to channel 2 of the 1103 while normalizing channel 1.
1. Set the network analyzer to measure transmission loss, S
21
. Attach cables to
both ports.
2. Set the display format to log magnitude, 1 dB/div, reference value 0 dBm,
and linear frequency.
3. Set the start frequency to
≈
1 MHz and stop frequency to
≈
2 GHz.
4. Set the test port power to 0 dBm.
5. Attach the cable from port 1 to the 1103 channel 1 input connector (Tek-
Probe connector). Use a male BNC adapter, if necessary.
6. Attach the cable from port 2 to the 1103 channel 1 output connector
(conventional BNC). Use a male BNC adapter, if necessary.
7.
Normalize the network analyzer to remove the loss through channel 1 of the
1103 power supply.
1.
Disconnect the port 1 cable from the 1103 channel 1 input connector.
NOTE
. Do not remove the end connected to the network analyzer. Connect the
cable to the BNC-to-Probe Tip adapter.
2.
Move the probe from the 1103 channel 2 to channel 1 input connector.
3. The setup should now appear as shown in Figure 8.
Preparation
Verification