TB 9-4931-534-35
NOTE
Sliding terminations and mismatches only: Adjust sliding load
to phase the standard with the TI by establishing a minimum
and maximum return loss indication.
Average the two
indications and record results as TI return loss.
(7) Disconnect TI from directional coupler and connect short to directional coupler.
(8) Adjust synthesized signal generator RF output level to reference established
on receiver system in (3) above.
(9) Repeat technique of (3) through (8) above two times and average values. Return
loss averaged value in dB will be within the limits as listed in Appendix A.
NOTE
If out-of-tolerance condition is consistently indicated, replace
waveguide adapters and repeat performance check.
(10) Repeat (7) above.
(11) Adjust synthesized signal generator frequency to next frequency test point
recorded in 7 a above and RF output level to reference established on receiver system in (3)
above.
(12) Repeat technique of (5) through (11) above for remaining frequency test points
determined in 7 a above.
b. Adjustments. No adjustments can be made; however, a correction chart may be
prepared showing actual VSWR values at test frequencies.
10. VSWR,
Waveguide Mismatches, and
Terminations (18 to
26.5 GHz)
a. Performance Check
(1) Connect equipment as shown in figure 3 and allow equipment to warm-up for 1
hour.
recorded in 7 a above and RF output level control for a power meter indication of -7 dBm.
(3) Determine signal generator frequency (LO) required for the desired
measurement by calculating the following equation: