Performance Tests
2
Keysight N1911A/1912A Service Guide
25
Output Standing Wave Ratio (SWR) Test
Description
Connector mismatch is the largest single contributor to measurement uncertainty,
so this specification must be warranted to provide assurance of instrument
accuracy. The 1 mW power reference level test must be carried out prior to this
test, as the VSWR specification is only valid at 1 mW. This test measures VSWR by
equating relative powers (measured by the test system power meter and its
sensors) when the power reference is exercised under different load conditions.
Equipment
– Required test equipment:
1 unit of 8753ES/ET network analyzer
1 unit of 85032B Type N calibration kit
1 unit of E4419B or E4417A dual channel power meter
2 unit of 8481D power sensor
2 unit of 11667A #001 power splitter
1 unit of 20 dB pad, male to female (e.g. 8491A)
1 unit of 30 dB pad (e.g. 11708A reference attenuator)
2 unit of 11730A power sensor cable
– An alternative network analyzer can be used, as long as it can measure S11 in
the 45 MHz-55 MHz range
– Either of these E4419B or E4417A power meters can be used
– These specific models of power sensors and power splitters must be used
– Any type of pad can be used (as long as there are no additional mating
connections, or differing pad values)
– 1 unit of 11667A, 1 unit of 8481D and the 30 dB pad combine to create the
‘Calibration System’
– 1 unit of 11667A, 1 unit of 8481D and the 20 dB pad combine to create the
‘Measurement System’
