HP 84811A Operating And Service Manual page 8

Page 6
HP 84811A
RETURN LOSS PERFORMANCE TEST (cont'd)
non-radiating open if operating below 10 GHz. Readjust the source so that the reading
on power meter #1 is equal to the incident wave reference level measured in step #3.
Measure and record the power level using power meter #2, at the reflected port.
Power Meter #2 (reflected port)_
5. Terminate the test port with a type N coaxial short. Readjust the source so that the
reading on power meter #1 is equal to the incident wave reference level measured in step
#3. Measure and record the power level at the reflected port as in the previous step.
Power Meter #2 (reflected port)_
6. Compute the average power measured on power meter #2 in steps 4 and 5 above.
This value is the return loss reference.
Return loss reference_
7. Connect the Peak Power Sensor and Peak Power Meter to the test port. Using power
meter #1, monitor the power level at the incident port and adjust to the same level
as in step 3 if necessary.
8. Read and record the power level indicated on power meter #2.
Power Meter #2_
9. Determine and record the maximum error of the test system using the following
data:
Test Frequency Error
100 MHz to 8 GHz
8 GHz to 12 GHz
12 GHz to 18 GHz
1.5 dB
2.1 dB
1.4 dB
Error_dB
10. Compute the return loss for D.U.T. using the following formula.
(Power Meter #2 reading — step 8)_
- (Return Loss Reference — step 6)-
+ (Maximum Error of test system — Step 9)-
Return Loss of D.U.T.-
For frequencies between 100 MHz and 12 GHz return loss for D.U.T. must be > 14 dB (or
< 1.5 SWR).
For frequencies between 12 GHz and 18 GHz the return loss for D.U.T. must be > 9.55 dB
(or <2.0 SWR).