Absolute Amplitude Accuracy at 50 MHz Performance Test

This test measures the absolute amplitude of the EMI receiver at 50 MHz. A synthesized signal source and two precision attenuators are used as the signal source to the DUT. A power meter is used to measure a reference power level from the signal source. The precision attenuators are switched to provide a series of signal power levels below the reference power.

The combined attenuation of the 10 dB and 1 dB precision attenuators is never set below 5 dB in order to maintain a good match between the signal source and the DUT. In addition, a 10 dB fixed attenuator is placed between the DUT and the precision step attenuators to further improve the match. Also, a 6 dB fixed attenuator is placed between the source and the step attenuator to control match.

Varying the signal level at the DUT input causes various ADC ranges to be enabled. The resolution bandwidth and frequency span on the DUT are varied, resulting in different pre-filter path and bandwidth switching errors. These errors are all absorbed by the DUT in giving its indicated reading of the exact absolute power levels presented by the signal generator/attenuator chain. The test is performed on both the RF Input 1 and RF Input 2.

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.

 

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Required Test Equipment

Test Equipment

Model Number1

Microwave Signal Generator #1

PSG Models
(see equipment list)

Power Meter

N1914A

RF Power Sensor

N8482A CFT

Attenuator, 10 dB Fixed

8491A Option 010, H33

Attenuator, 6 dB Fixed

8491A Option 006, H33 

Attenuator, 10 dB Step

8496G Option 001, H50 

Attenuator, 1 dB Step

8494G Option 001, H50 

Attenuator Driver

11713B

Attenuator Interconnect Kit

11716A 

Cable, Type-N

  • 2 required

11500C 

Cable, BNC

8120-1840 

Viking Cable (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
  • For Option 544

11903B

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

1250-1472
  1. Refer to the main Required Equipment table for a list of alternative models.

Connection Setups

Power Meter Calibration

 

Measure Source Setup

 

Absolute Amplitude Accuracy Test Setup (RF Input 1)

 

Absolute Amplitude Accuracy Test Setup (RF Input 2)