User`s guide

User’s and Service Guide 6-3
Service
Performance Tests
Insertion Loss
Step 1. Recall the full two-port calibration.
Step 2. Connect the cable that is attached to Port 1 of the 8720D to the
Transmission port of the 87050A Option K24.
Step 3. Connect the cable from Port 2 of the analyzer to Port 1 of the 87050A
Option K24. Select Transmission Port 1 using the 8720D. Record the
results in the Performance Test Record, Table 6-1 beginning on
page 6-6.
Step 4. Repeat step 3 for each of the remaining test ports 2 through 24.
Step 5. Repeat steps 2 through 4, but connect the cable in step 2 to the
Reflection port of the 87050A Option K24. In step 3, select the
Reflection port instead of the Transmission port.
Return Loss
This test will check both 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 6-2 beginning
on page 6-9.
Step 3. Repeat this measurement, but this time select no active port. The
display should show “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.