Input Attenuation Switching Uncertainty Performance Test

This test evaluates the accuracy of the input step attenuator (electromechanical or electronic). A source is connected to the analyzer through a composite 10 dB step and 1 dB step precision attenuator. The external (reference) and internal (DUT) attenuators are stepped in opposite directions to maintain –81 dBm at the input mixer of the DUT. The DUT display is used to indicate the difference between the change in the internal attenuator and the change in the external composite precision attenuator. As the DUT attenuator is changed, the reference level is changed to keep the trace near the same position on the display.

This test requires step attenuator calibration data to obtain valid results. Make sure you enter the calibration data for the step attenuators that you're using. Please refer to the Enter Equipment Calibration Data section in the TME Help for details on how to enter this data. You must enter the data for the following columns to obtain valid results: Attn(dB), Uncert(dB), and ReflSize.

Required Test Equipment

Test Equipment

Recommended Model Number1

Microwave signal generator #1

PSG models
(see main equipment list)

Attenuator, 10 dB fixed

8491A Options 010, H33

Attenuator, 6 dB fixed

8491A Options 006, H33

Attenuator, 10 dB step

8496G Options 001, H50

Attenuator, 1 dB step

8494G Options 001, H50

Attenuator driver

11713B

Attenuator interconnect kit

11716A

Cable, Type-N (m) to Type-N (m)

  • 2 required

11500C

Cable, BNC (m) to SMB (f)

8121-2063

Cable, Viking
(for attenuator control)

8120-2703

Adapter, 3.5 mm (f) to Type-N (f)

  • For 3.5 mm source

1250-1745

Adapter, 2.4 mm (f) to Type-N (f)

  • For 2.4 mm source

11903B

Adapter, 3.5 mm (m) to Type-N (f)

1250-1750
  1. Refer to the main equipment list for a list of alternative models (if available).

Connection Setup