User`s guide

User’s and Service Guide 31
87050A Option K24 Performance Tests
Return Loss
This test will verify the internal termination load of each port and the through match
when the appropriate input port is terminated with a load.
Step 1. Perform a one-port reflection calibration at the end of a 50 Ω cable over the
frequency range of 50 MHz to 20 GHz on the analyzer. Verify the calibration is
active and that the terminated cable displays a return loss of 0 (± 0.2 dB).
Step 2. Connect the cable (already connected to the Reflection measurement port of the
analyzer) to Port 1 of the 87050A Option K24. Connect a high-quality 50 Ω load to
the Transmission port of the 87050A Option K24. Measure the return loss of Port
1 by selecting Port 1. Record the results in the Performance Test Record, Table 9
beginning on Page 36.
Step 3. Repeat this measurement, but this time select no active port. The display should
indicate “Transmission-Terminated, Reflection-Terminated”.
Step 4. Move the cable to Port 2 and repeat steps 2 and 3, selecting Port 2. Repeat steps 2
and 3 for the remaining ports.
Isolation
Isolation must be measured only on adjacent ports. Two 50 Ω loads are required for this
test.
Step 1. Recall the full two-port calibration. Make sure the calibration is active and that
averaging is On when making measurements.
Step 2. Connect a 50 Ω load to the Transmission and Reflection ports of the 87050A
Option K24.
Step 3. Connect the two cables from the network analyzer to Ports 1 and 2 of the 87050A
Option K24. The exact order does not matter.
Step 4. Select Reflection Port 1 and Transmission Port 2. Set the 8720D to measure
Transmission. Record the results in the Performance Test Record, Table 14
beginning on Page 41.
Step 5. Repeat steps 3 and 4 for the next two adjacent ports; 2 and 3. Repeat again for
ports 3 and 4, then 4 and 5, and so on, ending with ports 23 and 24.